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Cooling Systems -- Problems & Solutions (Radiator, Fan, etc)

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Comments

  • ptinkptink Member Posts: 13
    help i have a 2003 chysler pt curs. and for the last 2 weeks I have had problems,
    it ran hot (but not up in the red) on a real cold day (18 over nite ) and i was told it was the thermastat well changed that and 2 days later i drove the car 35 miles and the needle never went off the C on the guage, took cap right off the radiater when I stopped and put finger in the water was cold!!!! , changed the thermastat again (figured it was a bad one) ran great for 2 days ... the temp. started to rise again...???
    no leaks no steam no hissing no nothing.... any guessess?? oh the water pump, and fan are working fine please help i love my car :cry:
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    You might have air trapped in the cooling system. When replacing coolant or opening up the system in any way, you have to follow the manufacturer's procedures for "bleeding" the system of air as you fill it.
  • ptinkptink Member Posts: 13
    thanks i will try that :)
  • a90myersa90myers Member Posts: 9
    Hello I have a 2000 Cadillac Seville SLS. I had the car in the shop a while ago because it kept using anit-freeze{none in the "burp" tank} The shop fixed the problem now it has started it again The car will run above the normal range before I add the anti-freeze. I add the anti-freeze, goes back to normal. It did it again. Added more anti-freeze. What can the problem be?
  • burdawgburdawg Member Posts: 1,524
    It's either leaking out somewhere on to the ground (obviously easy to tell) or it's leaking internally into the engine. It doesn't just disappear. What did they do to "repair" it the first time?
  • 0patience0patience Member Posts: 1,712
    Try this first..................

    Bulletin No.: 00-06-02-001
    File In Section: 06 Engine/Propulsion System
    Date: January, 2000
    Subject:
    Engine Running Hot, Overheating and/or Loss of Coolant (Polish Radiator Filler Neck and Replace Radiator Cap)
    Models:
    1999-2000 Passenger Cars and Trucks with Composite Radiator End Tank
    Condition
    Some customers may comment on one or more of the following conditions:
    ^ Engine running hot or
    ^ Engine overheating, and/or
    ^ Loss of coolant/low coolant message
    Cause
    The radiator filler neck may have an imperfection in the sealing surface.
    Correction
    Important: DO NOT REPLACE THE RADIATOR.
    Using a piece of 400 grit wet/dry sandpaper backed with a flat piece of wood, polish the filler neck sealing surface using a circular motion.
    Replace the radiator pressure cap with a cap of the same part number as shown in the GM Service Parts Catalog.

    Or this one..............
    File In Section: 06 - Engine/Propulsion System
    Bulletin No.: 99-06-02-019
    Date: December, 1999
    TECHNICAL
    Subject:
    Coolant Leak at Engine Heater Inlet Pipe Connector/Fitting (Tighten Connector/Fitting)
    Models:
    2000 Cadillac Seville with 4.6L Engine (VINs Y, 9 - RPOs LD8, L37)
    Built between VIN Breakpoints YU151384 and YU151853
    Condition
    Some customers may comment that engine coolant appears to be leaking from below the EGR valve pipe assembly at the rear of the water pump housing. A pink tell-tail line of coolant below the attachment of the EGR valve pipe assembly and the heater inlet pipe connector/fitting, at the rear of the water pump housing1 may be visible. An accumulation of coolant on the transmission case directly below the heater inlet pipe connector/fitting may also be visible.
    Cause
    This condition may be due to the heater inlet pipe connector/fitting threads with sealant not being sufficiently engaged to the engine assembly.
    Correction
    Ensure the heater inlet pipe connector/fitting is tightened to the proper torque specification.
    1. Disconnect the transmission shift cable from the shift lever.
    2. Use a 11/16 inch off-set wrench to tighten the connector/fitting taking care not to exceed 40 N.m (30 lb ft).
    Important: If the connector/fitting is torqued to specification, the cause of the coolant leak may be an insufficient amount of thread sealant. Apply GM Goodwrench/Locite(R) Pipe Sealant, P/N 12346004, (or an equivalent sealant that meets GM Material Specification 9985473) to the connector/fitting threads.
    3. Connect the transmission shift cable to the shift lever.
  • a90myersa90myers Member Posts: 9
    I don't remember what the dealer did but the cap was very hard to get off. The low coolant light does not come on. If you have the heat on and the temp goes up the fan blows cool air. After the temp goes down it blows heat
  • sandeep_kaileysandeep_kailey Member Posts: 1
    Hi,

    I have a 2002 olds Intrigue. about 2 months ago the water pump broke down and leaked . my uncle is a mechanic and he replaced the water pump . he told me that he thinks there is no or very little effect on head gasket or engine.

    car is running fine, the niddle of heat gauge on the dashboard is between 25% and 50 % of heat while car is moving, and shows about 55% when car stops at a signal, and goes back to less than 50 % when car is moving.

    the probelm is when car is ON but not moving for couple of seconds fan turns ON and I can feel the vibration of it like its running full speed.

    and it stays ON for about a minute after the car is turned OFF. I can hear the noise of the fan even if the hood is closed.

    and if I turn ON the car after say about 1/2 hour, I can't here the sound or feel the vibration.

    I think It only happens when niddle on temp gauge crosses 50 % mark .
    car doesn't overheat . no effect on the mileage.

    plz help me with this
    thanks in advance
  • burdawgburdawg Member Posts: 1,524
    That sounds like normal fan operation to me - when the engine temp reaches a pre-determined point the fan turns on, and turns off when it goes below that point. Some models also run the fan after the engine is shut off to cool the radiator down also, but not all. When you sit still with the cooling system warmed up and no air flowing over the fan then the temperature rises causing the fan to go on. Vice-versa when your moving the air flow over the radiator USUALLY is enough the do the job without the fan, but heavy traffic and ambient air temp has a lot to do with it also.
    If the fan is loud and causing a lot of vibration, it may signal that an impending fan failure is around the corner. It might be time to have the fan checked......
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I'd agree. Sounds normal except for the vibration part perhaps. When you turn an engine off, there is a "heat sink" effect, meaning the engine actually gets HOTTER then when it was running, --- for a few minutes. This might prompt the fan, through the sensors, to run for a while.
  • bolivarbolivar Member Posts: 2,316
    I agree with what previous posters said - this pretty much sounds like normal temp and fan performance.

    Unless, before the water pump replacement, the temp guage always stayed at the mid-point, and the fans seldom ran.

    If so, you might have air in the system. Is the coolant overflow/recovery container - the place where you check the coolant level - is it at the 'normal' level. If not, especially if it is empty, add a 50/50 mix of coolant and water and drive and stop the car a few times. After a car is warmed up, then stopped and cools down, if there is a need for additional coolant in the system, the vacuum generated will pull coolant back into the system from the recovery tank as it cools down. So, if it is low, add some and also check again after a few drives, because you might need to add even more.

    And, your uncle is not a bad mechanic if you need to add some coolant. This is something that can easily happen, not being able to get the system completely full, after opening up the system, such as replacing the water pump.

    A low level of coolant in the system, meaning there is air in the system, could cause variations in the temp guage reading, and could cause the coolant to overheat upon shutdown, causing the fan to run after shutdown.
  • edw6edw6 Member Posts: 2
    Hi, I recently purchased a 1993 chev truck with a 6.2 diesel motor and it has a coolant leak coming from the joint between the timing gear cover and the block. I removed the water pump and I see that the water pump pumped the coolant into the block through a passage in each side of the timing gear cover then into the block. My plan at this time is to replace the water pump and re torque the bolts on the water pump and cover in the hopes that will stop the leak, if it doesn't I guess my next options would be to try a stop leak product or take it to a shop ( to replace the timing gear cover gasket requires removal of the intake manifold, injection pump and oil pan etc...probably more than I am interested in doing myself.), so I am just wondering what your thoughts would be concerning this repair?, would you try a stop leak product or just take it to a shop if you were me?
    Thanks for your feedback.
    Ed
  • luvmystatusluvmystatus Member Posts: 4
    I have an `02 Dodge Stratus sedan, 2.7 liter 24 valve DOHC. Last month, took it into a dealer to have it serviced because, first of all, there was no heat coming into the car, the temp guage rose above normal reading, and some steam coming from hood. did not drive the car after this, except to take into dealer service center. they replaced the thermostat and housing(?). One month later, no heat again coming into car. temp guage ok. Took it in again. Now they are telling me that my water pump needs to be replaced, and while they are at it, i should have my timing chain replaced also because the coolant from the water pump could have corroded the bearing on my timing chain? I've called a couple of other mechanics to get quotes for having my water pump & timing chain replaced. First question: can a service technician tell if it is actually the water pump that is leaking without tearing the car apart? Second question: Is it necessary to have the timing chain replaced also?
    I can give more info if you would like.
    Thank You.
  • roger821roger821 Member Posts: 6
    Hey Guys,

    No one ever got back to me on this problem. Since I first left this message, I have replaced my water pump and timing belt, and it is still happening. Does anyone know what the problem can be here? Thanks...
  • dgrasserdgrasser Member Posts: 12
    If the water pump is leaking, you should be able to see coolant on the driveway. From my experience, the bearings usually go out first and the coolant ends up leaking from the bearing housing on the water pump.
    W.r.t. the timing chain, that sounds like non-sense that the coolant leaking would come into contact with the chain and cause it to corrode.
    Now, if in having to remove the water pump requires that they remove the timing chain housing and expose the time chain anyway, and if you think you have high enough mileage that warrants changing it now, that is another issue.
    I have had a couple dozen vehicles over my lifetime and have NEVER, EVER had to change a timing belt on any of them.
    This sounds like the old, "As long as we're changing your oil, let's change your air filter, PCV valve, etc.", that is to say, once they get your car into the garage, they will want to "fix" alot of things and charge you for it, even if it really doesn't need fixing/changing !
  • luvmystatusluvmystatus Member Posts: 4
    Thanks for your response. In my quest to get quotes on this repair, 2 of the service men I've talked to, didn't understand why the original diagnosis included replacing this timing chain either. My car does have 121400 miles on it. I thought that was pretty average with today's cars. Knowing this, do you think it would be a good idea to have the timing chain replaced, or just checked?
  • ptinkptink Member Posts: 13
    ok I own a 2003 chrysler PT it ran hot last month and I have changed the water pump ($700.00 labor) the thermostat, the sensor, the hoses are fine, there are no leaks any where and I have bleed the line it is still running hot the pump is working, and the thermostat is too... WHAT ELSE COULD THIS BE :sick:
  • burdawgburdawg Member Posts: 1,524
    A clogged radiator, failing temperature sensor (if there was no outward sign of overheating), or intermittent/ failed cooling fan.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    also head gasket issues. But radiator is a good place to look, especially if the car is an automatic.
  • ptinkptink Member Posts: 13
    thanks we drained the radiator when we did the water pump and put new fluid in. and we changed the sensor also. I don't see any water in the oil and there is no leaks any where on the engine
  • ptinkptink Member Posts: 13
    i was afraid you'd say head gasket... it did not run hot enough i don't believe to warp it.... but they are alum. heads is there any help for that but a new engine because i hear it can mess with the rest of the engine.
  • burdawgburdawg Member Posts: 1,524
    Just draining the radiator and refilling it won't help if it's clogged. The only remedy for this car with a clogged radiator is to replace it, since it can't be taken apart and rodded out. Hard to believe a clogged radiator though on a 5 year old vehicle, but possible.
    Shifty may have a point with an internal coolant leak, but you didn't say you had to add coolant to my recollection.
    How many miles?
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Here's a pretty exhaustive discussion on overheating:

    http://www.troubleshooters.com/tautomot.htm

    As you can see, overheating is really a complex problem that requires very careful diagnosis.

    As a general rule, if you overheat at LOW speeds but not on the highway, you have an AIR problem

    If you overheat at highway speeds but not necessarily at idle, you have a CIRCULATION problem.

    If you overheat VERY quickly, you probably have either a stuck thermostat or a bad head gasket (also known as a Tea Kettle, because it boils water).

    Very often, water pumps and thermostats are replaced for no good reason, because the mechanic is not thinking logically or doing simple tests.

    But sometimes even the best mechanic pulls his hair out (not in my case as I don't have much) with an overheat problem, because you can't really SEE or COMPUTE the problem, You have to use other senses to get at it.

    In your case, I'd test for combustion gases in the coolant, and I'd pressure the system with a pump and pull some spark plugs and look for coolant on them.

    If that's not it, I guess I'd pull the radiator or at least have it inspected by a pro. I presume your cooling fan is in order and I presume you DO overheat on the highway speeds.
  • ptinkptink Member Posts: 13
    miles are 140,600.coolant was leaking out slowly thats when i took it in and they told me it was the water pump but know i have not been having to add any on a reg. bases
  • ptinkptink Member Posts: 13
    wow there is alot more to running hot then i thought !!!
    ok i got alot to think about ... it now runs hot quickly when i first had it fixed (thermostat ) it did not even move off of cold for 35 miles and the coolant was still cold when i got home.
    the car has never steamed up nothing like that but i read where that didn't mater a head gasket could still warp.
    and it went 2 weeks then ran hot on the expressway this last time after everything had been fixed....i went 45 miles in traffic to work just fine the needle never moved till I came off the express way then shot up ...... then on the way home 9 hours later it started running hot after only 5 miles on the expressway, no traffic.... that's when i parked it, i could not think of any thing else to do to fix it.
    thanks for all your help
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Very weird. I wonder if your cooling system has air pockets in it and needs to be bled, because the behavior seems so inconsistent.

    A bad head gasket may not mix water and oil. That's not a sure way to tell since it depends where the head gasket breaks or leaks. It can leak water into oil, oil into water, exhaust gas into water, or everything to the outside of the engine.
  • luvmystatusluvmystatus Member Posts: 4
    I've just taken my car in to another mechanic to "verify" original diagnosis from a dodge dealership service center. The original diagnosis was that I need a new water pump & should have the timing chain replaced, at a cost of $1250.00. My car has 121,000 and is an '02 Stratus, 2.7 liter, 24 valve DOHC. This second diagnosis, from a non-certified dodge mechanic, did some research on my car prior to me coming in. He asked me about whether there were puddles under my car. I park my car in the garage every night. He asked me if I were adding coolant, how much & how often. The answer I gave him, was that I hadn't seen a puddle except for the day after I had the first diagnosis. But because of this first diagnosis, I have been adding a small amount of coolant every other day while the car was cold, only because I couldn't really see the minimum marking on the tank, and because I wasn't sure if what I could see was actually coolant level, or if my tank was just stained "orange". So I have been adding a little. Anyway, what this second mechanic told me, was that it is NORMAL, for my type of car to "weep" coolant. He told me that I should place a piece of cardboard under the right side of the engine, and check the cardboard periodically to see if there are just drips or if there are actual puddles. Is this "weeping" normal for my type of car??? If so, why?
    Please help.....I've talked to 5 different service centers, and they are all telling me different things!
    Thanks.
  • luvmystatusluvmystatus Member Posts: 4
    To give you more info, the reason that I had the first diagnosis, was because the heat in my car totally went out. About a month prior to this, my heat went out and my car overheated. So I brought it in between christmas and new years, and they replaced my thermostat and housing. After that, I did have heat, but it wasn't "hot" like i've normally experienced with my car. Then I started to notice - about 2 weeks ago, that I would only get heat when I was driving on the highway, not when I was driving at lower speeds. Then finally, no heat. That is why I took it in again to the service center that replaced my thermostat, and thats when they told me i need to replace my water pump and timing chain. That I've lost a gallon of coolant. So I asked them, "wouldn't I see puddles under my car if I had lost that much coolant?" They told me that it probably landed on the frame and evaporated, and that is why I didn't see puddles. Now, obviously, I have no mechanical background, but I find it very hard to believe that losing a gallon of coolant in one month, and not seeing puddles, is a hard one to swallow. But, like I said, I have no mechanical background, and I know that cars are very sophisticated nowadays. Anyway, the "second opinion" mechanic told me that it is possible, that when they replaced the thermostat a month ago, that they might not have bleed the air out, leaving an air pocket in the system. And that it is possible that I didn't lose a gallon of coolant, that's just how much of an air pocket was in my system when they looked at my car 2 weeks ago. What do you think???????? I need an objective, non-monetary opinion. I love my car, and would like to keep it as long as I can. However, I can't keep putting $1000.00 into it every month.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Everybody is guessing is my conclusion/opinion.

    Have the system pressurized (they use a pump attached to the radiator) and see if a leak appears.

    No, you aren't supposed to "weep" coolant.

    No, sprayed coolant doesn't "evaporate" on your chassis---it's quite sticky and oily in nature and will form a residue.

    Water pump? Possibly, if the impellers (the little blades inside) are eroded and eaten away. But if a water pump were leaking, you'd see it.

    Over-heating can be a very complex problem to diagnosis and one has to go at it step by step. A mechanic just can't throw parts at the car and hope he/she hits something.

    If no leaks appear upon pressurization, the spark plugs should be pulled out to check for coolant on them (head gasket).

    You could be burning the coolant in other words.

    Timing chain? If your car has a timing chain, instead of a "belt", then it should never need replacing. I can't recall which your engine has. If it's a belt, then follow the recommended replacement mileage, which you can find here:

    http://www.edmunds.com/maintenance/MaintenanceServlet
  • ptinkptink Member Posts: 13
    welcome to my world this is the same thing that happen to my 2003 PT cruiser I have tried everything you did. I have replace every thing bled everything and pressurized everything and it still runs hot... i love my car too but i just parked it :sick:
  • roger821roger821 Member Posts: 6
    This is a repost of a message I sent back on January 3, and no one ever responded. Since I originally posted this message, I have replaced my timing belt and water pump, and the same thing is happening. It seems to happen only when I'm running the heater - otherwise, the temp stays in the normal range.

    If this is a thermostat issue, it should be easy to fix, but even the mechanic who replaced my timing belt didn't know exactly what the problem was. Can any of you help me?

    "Hi there...

    I have a 1997 Honda CR-V with 143K miles on it. Today when I was driving home from work, my dash temp was showing the regular 1/2 setting, which is where it has stayed after I replaced my radiator 6 months ago. Tonight, it suddenly dropped and almost went back to the cold setting - it dropped to about 1/8 while I was driving on the freeway at speed. It stayed there even when I slowed down off the freeway for about 5 minutes, and then it returned to the normal setting. I didn't notice any smells, steam/smoke, or noises in my engine. The air temp is now 42 degrees in Houston, which is way colder than normal, but my car's never done this before. Does anyone have any ideas as to what happened? Thanks..."
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Yep sounds like thermostat sticking wide open. Of course, one can't always trust a temp gauge, and a real reading with a mechanic's thermometer would be in order.
  • kiawahkiawah Member Posts: 3,666
    Roger,

    You may have an electrical problem, as opposed to the temperature actually chaning. Could be a temperature sensor, wire connector at the temperature sensor is loose, or the gauge itself is going bad.
  • detomacdetomac Member Posts: 1
    My 96 olds regency, 3.8 front wheel drive is leaking coolant from a tube(may go to head) above the water pump. What is this tube and how do I repair this?
  • kiawahkiawah Member Posts: 3,666
    Don't know specifically about that tube in your vehicle.....but I had a 96 Suburban that had an aluminum tube which had a leak. I ended up going to the dealer to get a replacement. Had to buy the whole assembly (couple long hoses and the tubing), even though I only really needed the tubing.
  • traci65traci65 Member Posts: 1
    I have a 99 Ford Taurus. My trouble started with no heat. I have had the system flushed several times and the last time I took it in for no heat (approx. one month ago) the mechanic told me all it needed was antifreeze. He added antifreeze and I had good heat. As I said that was the end of January. Since then I have had to add a gallon of antifreeze on Feb 11 and on Feb 19 because I had no heat again. Just last night it happened again...no heat. I need to add more coolant today...less than one week since the last time. I have been reading some of the posts here and notice no white smoke from the tale pipe. The only thing I have noticed is that there are times when I stop and there is what I considered to be steam coming from under my hood. I have had the thermostat changed and my temperature gauge never rises above the halfway point so I'm not "overheating". Honestly, I'm tired of the whole trial and error way of figuring out what the real problem is. I just want to know what it is so I can fix it. There are no puddles under my car so it doesn't appear to be leaking onto the road.

    Yes, I'm a female and no absolutely nothing about cars. I desperately need help here. I'm afraid if I go into a shop they will talk me into something that is not the true problem.
  • kiawahkiawah Member Posts: 3,666
    You are either leaking anti-freeze out onto the ground (or evap into the air).....or you are leaking into the engine. If going into the engine depending where it is going, it either gets burned up and sent out the tailpipe, or it gets into your engine oil and ruins your engine bearings.

    If you are tired of the trial and error way of fixing something, take it to a compentent shop where they can pressure test your radiator system and figure out that you are loosing pressure or not (we pretty much know that you are).....and then they can detect if it is leaking external to the engine. If leaking and not external to engine....then you know you have an internal engine problem and probably need new head gaskets.

    If its leaking external to the engine, most of the time you'll be able to see the leak. Leaks on the radiator may be difficult to see, depending upon where it is.
  • jipsterjipster Member Posts: 6,244
    The "Low Coolant" light has started to come on with a cold engine. When the engine warms up, usually within 1-5 minutes depending on how cold it is, the light will go off. I put a couple cups of coolant mix in the resevior, it was slightly below low, but this didn't help. When I took the radiator cap off with cold engine it was down maybe an inch. The temp gauge has functioned as it normally does. Any ideas?
    2020 Honda Accord EX-L, 2011 Hyundai Veracruz, 2010 Mercury Milan Premiere, 2007 Kia Optima
  • kiawahkiawah Member Posts: 3,666
    Your radiator should be filled completely.

    There is an overflow tank associated with the radiator. It should be filled up to between the lines. Explaining operation. Radiator is completely filled up. As the engine warms the fluid in the radiator expands and is pressurized. When the pressure exceeds the radiator cap pressure rating, the cap opens slightly which allows the excess to flow into the overflow tank and it is captured. When the engine cools, the fluid cools and shrinks in volume, drawing a vaccuum on the radiator cap, which draws fluid back out of the overflow tank and refills the radiator.
    So the radiator should always be completely filled up to the top.

    Top off your radiator, and then fill up the overflow tank to in between and hot and cold markings with a 50/50 mix of antifreeze and water (or the premixed).
  • burdawgburdawg Member Posts: 1,524
    Good advice from kiawah, let me add my 2c. The low coolant sensor is in the overflow tank, consisting of a switch and float. It's possible the switch is going bad and has become sensitive to the ambient temperature. Try shaking the overflow tank a little when it's cold and the light is on to see if it goes off.
    It doesn't sound like the radiator was low, 1" or so below the cap could be normal for cold. If you had to add coolant to the overflow tank because it was low then I'd keep an eye on it for awhile just to be sure there's no problem cropping up......
  • jipsterjipster Member Posts: 6,244
    Thanks for the comments all. I just checked the radiator and it was full to top (this time but not last time???) ... overflow tank was fine as well. I tapped the tank to see if the light would go off, it wouldn't. But, it's bolted down pretty good so couldn't get a "shake", only a tap .

    I have had to add a little coolant in the past. I have always suspected a very very slow coolant leak. The dealership tested a couple years ago and said no leak. But, I did see a little brownish/blackish gunk (oil) stuck to the filler neck. Nothing in the coolant itself that I could tell. Oil level and dipstick is always fine. So, I guess that would be the manifold gasket?
    2020 Honda Accord EX-L, 2011 Hyundai Veracruz, 2010 Mercury Milan Premiere, 2007 Kia Optima
  • burdawgburdawg Member Posts: 1,524
    Hard to say. A pressure test is the only true way to know for sure. I've had cars that seeped coolant a little, especially in cold weather, and actually I have an MGB that does it now. Once it's warmed up it stops, and it's a really small seep from one of the radiator hoses where it connects to the radiator. You probably wouldn't know it unless you looked for it. The only way I know is that I never drive the MG in and out of the garage, I only push it, so those few drops on coolant on the floor aren't hard to see.
    Check along the side (or top/bottom) tanks on the radiator. These modern aluminum radiators with plastic tanks that are crimped to the core have a tendency to leak slightly at the core to tank seal, and your about at the age where it happens. It can be very difficult to see. You could also have a leaking radiator cap that allows a little seep to escape when it warms up, or a slightly leaking heater core.
    I think you can see where this is going, back to the pressure test.
    One other thing, it's also possible that the overflow tank has a small leak in it, either through a stress crack or the seal for the low level sensor.
  • kiawahkiawah Member Posts: 3,666
    You shouldn't really ever have air in the top of your radiator, if everything is working correctly. When the radiator gets hot, it builds pressure, and the cap releases the pressure, then the air gets purged to the overflow tank (since the air is always at the top of the radiator). When it cools back down, it draws in coolant.

    If you do have air, then there are a couple of typical causes:
    - you could have a leaky overflow hose (that goes from the radiator cap to the bottom of the overflow tank). If this had a leak, when the radiator was cooling back down and sucking the coolant back into the radiator, it could suck air in. You might want to cut an inch off where the line attaches to the radiator, give yourself a new rubber stretched joint.
    - you could have a bad radiator cap. The cap is built to hold pressure up to a given amount of pounds and then open up to allow the radiator to purge air/coolant into the overflow tank. Upon cooling and reduction in pressure, overflow coolant should be sucked in. The rubber seals and spring of the cap enable this, and there should not be any leaking (pressure in either way), to the outside air. The seals should only pass coolant between the radiator and the overflow tank.
    - your overflow tank is empty, and it's drawing in air instead of coolant
    - the worst....a leaking head gasket. If the gasket is damaged, then air mixture from one of the cylinders can be forced into the cooling chambers as the piston compresses the mixture. Since the pressure in the cylinders is 150ish lbs-ish, and the pressure in the coolant is 15 lbs-ish. the air is forced into the coolant, which is then ultimately purged out and released by the radiator pressure cap.

    It is also possible that a hose is allowing air into the system when it cools down. However, if it was that loose that air would enter there versus the radiator cap...then you'd see the leak as the hose was pressurized.

    So when checking your radiator when it's cool, if you have air, you have one of those problems.
  • jipsterjipster Member Posts: 6,244
    thanks for the additional input guys. I'll do the visual checks you guys suggested. I'm due for an oil change in about a month, I'll have the dealership do a pressure check. I don't think it urgent, and I have a coupon for free coolant system check with regularly scheduled maintenance. Will post back in about a month on the results.
    2020 Honda Accord EX-L, 2011 Hyundai Veracruz, 2010 Mercury Milan Premiere, 2007 Kia Optima
  • jipsterjipster Member Posts: 6,244
    I'm guessing a coolant system pressure test wouldn't exacerbate the problem of a cracked gasket? I plan on keeping the car a couple more years. A small coolant leak that isn't hurting anything is something I can live with. But, don't want to go to the land of big bucks with a car that is almost 10 years old.
    2020 Honda Accord EX-L, 2011 Hyundai Veracruz, 2010 Mercury Milan Premiere, 2007 Kia Optima
  • ray80ray80 Member Posts: 1,655
    Is this a 6 CYL that is well known for intake manifold gasket troubles (3.X) ? Typicly I think you may be able to see it as an oily looking residue around gasket area (externaly)
  • nettykayenettykaye Member Posts: 1
    I just recently bought a 2003 Jeep Liberty. I noticed that there is no water in the overflow (where you add the water). SO before leaving for work I filled it to the fill line. I just checked it again (4 hours later) and there is NO water in the overflow again......Is that normal???? :confuse:
  • jipsterjipster Member Posts: 6,244
    Is this a 6 CYL that is well known for intake manifold gasket troubles (3.X) ? Typicly I think you may be able to see it as an oily looking residue around gasket area (externaly)

    It's the 3.8 engine, suppose to be one of G.M's best. I have read before that select model years had trouble with intake manifold gasket. When I bought the car 4 years ago there was a bit of oily residue around what I thought was the valve cover gasket. Never a problem... doesn't seem to have gotten any worse.
    2020 Honda Accord EX-L, 2011 Hyundai Veracruz, 2010 Mercury Milan Premiere, 2007 Kia Optima
  • ray80ray80 Member Posts: 1,655
    I took a quick look around here and there and while it may not be as prevalent on the 3.8 as it is the 3.1 or 3.4, it appears it does happen. Lookin at the engine from top down, the valve cover gasket should be first followed by intake gasket . If it is that it may eventually continue to crack and leak into engine oil, wouldn't be good.
  • burdawgburdawg Member Posts: 1,524
    No. If the overflow is empty you should check the level in the radiator if possible (some don't have radiator caps). Once all is filled up to normal, then watch for the coolant level dropping in the overflow. My feeling is there's a problem unless on the off chance the coolant was just changed and not filled up all the way.
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