Engine overheating - summer problem?

yabadayabada Member Posts: 19
edited March 2014 in Chrysler
During last hot days the temperature gauge in my Concorde LXi goes all the way up till the last white line while using AC. It happens in stop and go traffic but I don`t think this is normal. After about 20-25 minutes of heavy traffic I have to turn off the AC and open the windows. I had the same problem when driving with AC turned on with the speed of about 90 miles /hours for about 2-3 hours. The strange thing is that when I stoped and turned the engine off, after about 10 minutes, the engine temperature dropped 3 points on the scale. Anyway, what may be the problem.
The AC, the thermostate or the temperature sensor. Or maybe it is absolutely normal. Anybody with the same problems?


  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    My LXi (and yours, I'll bet) has a remote overflow tank that is part of the PRESSURIZED zone of the cooling system. The radiator cap sits right on the remote tank, not on the radiator. Let me discontinue further explanations and ask you to check and see if in fact you have enough coolant and water mixture in your cooling system. It can be hard to inspect and see the level! This can be critical after a bit of leakage. Also, replace your radiator cap if it does not test out to hold prescribed pressure. Please let me know what you discover.
  • yabadayabada Member Posts: 19
    Thanks for your message. This is a '98 Concorde that I bought 2 weeks ago so I am not very familiar with the engine compartment. I will check the coolant level tomorrow, though it is indeed difficult to see.
  • alcanalcan Member Posts: 2,550
    Verify that the engine cooling fan comes on when the AC is turned on.
  • jgmilbergjgmilberg Member Posts: 872
    If you just got the car I would change the thermostat, and flush and fill the cooling system, just to be safe. That is one of the first things I recommend doing when you buy a used car, along with an oil change, air filter, and pcv valve. Alcan is also on a good lead, make sure that fan comes on, if not you have problems that need to be addressed. Another thing to look at is the radiator, make sure it's cooling fins are not clogged up. If you are handy loosen the radiator, and get the leaves and other debris from in between the radiator and A/C condenser. It is not unusual for the engine temp to rise slightly with the A/C on, but if it takes you to the edge of overheating it needs to be looked at. The A/C condenser is in front of the radiator, so the air going through the radiator is going to be warmer than regular air temp while the A/C is on.
  • yabadayabada Member Posts: 19
    Thanks a lot. I just checked the coolant level and it`s OK. The fan comes on also. The dealer who sold e the car said that all oils and liquids were changed in the car be their mechanics (huge dealership). I checked them and I can confirm that they are fresh but I am not sure about the PCV valve and thermostat. I don`t think they were changed, so this is my next step. My temporary emission inspection expires in two days so that would be a good opportunity to visit a mechanic.
    I will post you with my findings.
    Thanks again.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Also it depends on how extreme the outside temperature is.

    If you are crawling in traffic in Phoenix AZ in summer with the a/c on, or slowly and laboriously climbing some long hill in brutal hot weather, I suspect just about any car will overheat. There's a point here where heat simply cannot be dissipated fast enough.
  • yabadayabada Member Posts: 19
    In my understanding any car (pretty new I mean) should handle a 90-100°F weather but I am afraid I was wrong.
  • swschradswschrad Member Posts: 2,171
    of course, that's assuming they can move along so there is an assist in airflow through the radiator than just the fan. on a upper-70s day or warmer, during a/c testing, GM manuals used to warn that a big old shop fan should be put in front of the radiator to insure the car didn't get out of the normal range. a/c is from a 10 to 15 HP load depending on car size and thus compressor size, and there is generally also an idle speed boost when the a/c is on to prevent stalling at idle, so you are working the car noticeably just sitting and honking in traffic.
  • jgmilbergjgmilberg Member Posts: 872
    It really depends on the car and the type of driving you are doing. If the previous owner did not maintain the car you could have a plugged/corroded radiator from the coolant turning acidic. If that is the case no amount of flushing will help at all. Get that thermostat changed out, that should help. If it still is a problem before you replace the radiator loosen it and check for debris stuck between the radiator and condenser. That debris really cuts down on the cooling ability, so get that cleaned out good. You almost have to remove the radiator to clean it out good. Autozone sells the radiator for $320 so make sure it is clean before you change it out. Also while you are messing with the thermostat change the radiator cap, it's cheap insurance against overheating.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    If you have a good radiator shop in your town, you might want to go there for a little advice on your situation. They can take a look and give you their opinion.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Your radiator can be flow tested. It doesn't have to be "fixing by guessing".

    Overheating is actually a difficult diagnosis since there are so many causes, many of them internal and not inspectable.

    You could also try some "water wetter"--might help a little.
  • jgmilbergjgmilberg Member Posts: 872
    I forgot all about that water wetter stuff. A friend of mine uses that in his big block Camero. It cut his temp down by about 10 degrees. You can get it from http://www.summitracing.com or http://jegs.com

    Shifty I never heard of a shop flow testing a radiator. I may be going to the wrong shops, none of them ever offered to flow test it, they just said "You need a new one" I wish I could find a shop that would do more than leak test the things.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    Some radiator shops are just drop off places for people in the car repair business. They stick to fixing delivered radiators. At the other end of the spectrum there are some radiator shops that do it all, and could well be called automotive cooling system specialists.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Here's how I look at it...if I can look down into my radiator and see a clogged, rusted mess, okay, you pull it out and recore it---but if the core looks good visually or I can't see it, then I want it flow-tested and I'll pay for that.

    Otherwise what have I got? Potentially, a brand new core and the car still overheating.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    My most recent encounter with a radiator specialist shop was about five years ago, and the propietor is a guy I've known forever. He rebuilt my radiator core (rodding and cleaning, soldering). He is a master of the business and a fine human as well. He gave up the shop to his partner for health reasons not long ago. I am wondering if he is an Americana treasure that will not be replaced after his partner retires, too. Maybe the general expectation is now becoming a change of parts with no more rebuilding.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    Especially with plastic radiators---sure, switch and swap is the future, let's get used to it.

    Things change, "progress" marches on, nothing you can do about it except act silly and wave your arms around like a lunatic demanding that your radiator core be flow-tested rodded and repaired.
  • yabadayabada Member Posts: 19
    Well, during my todays visit at a local mechanic I described the problem and asked for the price of the thermostat replacement. The guy ( in spite of the almighty dollar) didn`t want to change it because as he said "I don`t have a problem with the thermostat". During the emission test (NY)
    the engine didn`t overheat, so his conclusion was that everything is OK. The next thing I plan to do is to flush the radiator. Do you know what cost I should expect. Unfortunately I can`t do it myself. The car has 69k and was used in TX, though I don`t know the owner and I don`t know how he maintained the car. Do you think this is my last resort before changing the radiator?
  • yabadayabada Member Posts: 19
    Can anybody help me to locate thermostat in Concorde LXi (98)? I decided to replace it myself if the job doesn't require disasambling the whole engine. I found one on www.chryslerparts.net for
    $12.30 I believe this is a fair price.
  • swschradswschrad Member Posts: 2,171
    literally. two big hoses come out of the radiator. One goes direct to the bottom of the engine. the other goes up higher, near the water pump. at the point of attachment, there is a metal (usually cast iron) knobby held onto the engine by a couple bolts. get a replacement gasket and some #1 "non-hardening" gasket compound when you get a thermostat, because when you drain the radiator, and pull those bolts, underneath is the thermostat. put the new one in the groove exactly as the old one was (there is generally a preferred "up" position), put the gasket with a thin continuous layer of gasket compound on there in the right posiition (don't get any sticky goo on the 'stat) and bolt the knobby flow director back on over it. refill the radiator and engine with the proper 50/50 mix, leave the cap off, and start up the car. if it leaks, fix the leaks. if not, keep pouring in 50-50 until the 'stat opens at temperature, the level of fluid drops, and after you fill it up this time, it starts to rise and trickle over the neck of the radiator. now stop and cap everything up, make sure the overflow bottle is up to the "full cold" mark with good 50/50, restart and check for leaks as the heater blows hot air and the engine gets fully to warm-up.

    no leaks? the job is done. leaks? go back and undo the short cut ;) don't ask me how I know that.
  • jgmilbergjgmilberg Member Posts: 872
    You can find the t-stat at the local parts store. You can get the actual location of the t-stat from the store, and the gasket and gasket sealer. The sealer is in a little brown bottle the stuff I use is called Indian Head. The parts are very common to the stores, and are probably cheaper than ordering online and paying for shipping.

    Another thing I do is boil the t-stat with a thermometer in the water before installation to make sure the thing opens at the right temp., I have had them not open at all brand new from the box.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    A bad thermostat will usually give you a pretty fast overheat won't it? I mean, it's not like you can drive long long distances with a thermostat stuck shut, correct?
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    You can drive forever with 'em stuck open, but your engine will not maintain an optimal running temp, nor support the heating system in cold weather. Etc. ad nauseum.
  • zr2randozr2rando Member Posts: 391
    It's easy and doesn't take long to do.
    Fleetwoodsimca, I have also heard of some vehicles that if the thermostat was removed or was stuck open, would actually OVERHEAT because the water did not stay in radiator long enough..(older vehicles had bigger radiators and would cool enough (or too much actually like you described) but newer vehicles could overheat, weird huh?.
    I have noticed an odd behavior with the thermostat on my Blazer. My Blazer is a 95 with the 4.3 motor.
    Motor has been replaced, and the original replacement was also replaced under warranty (bad reman job).
    I have noticed ever since it was new, and this behavior has been consistent with all 3 motors and all 6 thermostats (I have replaced them a couple times just checking them)...that the first time the thermostat opens it is slightly hotter than the normal operating temp. After the initial opening the temp stays at normal temp (except on VERY hot days where it operates slightly hotter especially on uphill grades). I have a 99 truck, same engine, does NOT show anything like this.
    I think there is an air bubble at the thermostat that delays the first opening, and then the bubble goes through the system and the thermostat is properly submerged and works normal after that point, but I'm only theorizing here. Anybody got any other suggestions?
    I think that year model is just marginal on cooling capacity actually.
  • SPYDER98SPYDER98 Member Posts: 239
    I think every car has its limitations. Last summer on my way to the beach, my car began to overheat for the first time ever on the highway. Especially on the inclines. It was also 100 degrees that day.

    I've never experienced overheating since.
  • bolivarbolivar Member Posts: 2,316
    If you can't 'find' the thermostat on your own, I'm not sure I can recommend you attempting this on you own.

    It could be a relatively simple job. Or it could be a mess. On my 4L Ranger truck, the 3 bolts holding the housing on took 2 different size wrenchs. And one of the bolts was tough to get out and back in. I've done a fair amount of mechanic work, and I once broke a housing putting it back on.

    I just would not recommend this as a first attempt at mechanicing.....
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    Good advice. Concorde Chryslers have a special air bleeding valve at the thermostat area to deal with that would complicate matters.
  • jgmilbergjgmilberg Member Posts: 872
    I have had a couple of thermostats not open completely, the car would run at normal temp around town, but when you got out on the freeway for 1/2 hour it would start to overheat, not enough water passing through the radiator. That is one of the reasons I test them now before putting them in, makes sure they open completely and at the correct temp.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    Buying top quality thermostats can save a lot of repeat work, as well. I try to buy premium quality ones at NAPA, when they are available for my particular applications.
  • bolivarbolivar Member Posts: 2,316
    The only new thermostat I've ever had a problem with was a NAPA. The first time it opened, from a cold startup, from the temp gauge it looked like it was opening about 20 degrees (or more) above the 'usual' temperature. After the first opening, it seemed to work fine.

    But this bothered me so much, I could just see the thing staying closed and overheating, I pulled it, made NAPA refund my money, and put a Delco in the GM vehicle. It worked fine.
  • jgmilbergjgmilberg Member Posts: 872
    I get the OEM ones if available, if not I get Robertshaw. I still boil the things to make sure it opens at the right tempo and all the way. I doesn't matter how good the manufacture is, they still end up with a bad one from time to time.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    I have found that the NAPA premium thermostats are very dependable in the German Ford pushrod V6 4 Liter engine. I had an early demise of the OEM 'stat in my bought-new 1993 Explorer, and never touched it again after installing the NAPA. I now have a 1999 Ranger with that motor (last year for push rod, I understand) that did the same tango on the OEM, and I have replaced it with a NAPA. I am confident... I think!(:o/
  • yabadayabada Member Posts: 19
    I just returned from a weekend in Vermont.
    While driving in those mountain terrain my Conc`98 overheated again even without the AC on. I believe it must be a thermostat problem. I suspect that it doesn`t open completely but I want to flush the radiator also. What should I do first, change the thermostat or flush the radiator. I want to find out what caused the overheating problem an that is why I don`t want to do it at the same time.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    Have you checked your water pump?
    How many miles on that car?
    Is "Conc" a Chrysler Concorde?
  • yabadayabada Member Posts: 19
    1. I didn`t check the water pump
    2. 70,000
    3. "Conc" is Chrysler Concorde (LXi, `98)
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    After posting my last note, I later recalled your vehicle from prior postings. Checking out the sanitation on the radiator is a good idea, considering you have 70K. You may need to get the radiator "rebuilt" (rodded and cleaned, at least) or replaced. I read in Consumer Reports that Concordes are noted to have problematic cooling systems. I have a 1996 with just under 22K on it. No, that ain't no typo!
  • jgmilbergjgmilberg Member Posts: 872
    Pull the t-stat, and put it back together w/o the t-stat, then flush it. Then take it apart install the t-stat again and fill the system with new antifreeze. From what you are saying I would really look at the radiator. If you can't look into it, see about having flow tested. Also make sure there is not a bunch of junk between the A/C condenser, and the radiator as well.
  • yabadayabada Member Posts: 19
    Today I visited a mechanic and asked about the price of the thermostat change. He asked me to open the hood and said "it`s a huge job, I have to disassemble the upper part ( he called it somehow) so it`s gonna be about $200-$300". I didn`t like it too much so I went to another guy who lifted the car and said the thermostat is in the lower part of the engine and he would charge me $95. I told him about the other guy but he insisted that he`d seen the thermostat from the bottom. I didn`t have time to go somewhere else but I will definitely do it on Monday.
    My car is Concorde LXi `98.
    Is it that difficult to find a thermostat in a
    fairly popular car like Concorde?
    I used to do some easy job on my previous cars
    but it was in `70s when the guts were pretty straightforward. Now with all this electronics under the hood I have to rely on others who are supposed to know their damn job
  • alcanalcan Member Posts: 2,550
    Mitchell Labor Guide, hours:

    Thermostat &/or Outlet, R&R
    Concorde, LHS, 300M
    2.7L engine.......... 2.0
    3.3L engine.......... .7
    3.2L, 3.5L engines... 1.3

    Time depends on the engine, which you didn't post.
  • yabadayabada Member Posts: 19
    Thanks alcan, but what is Mitchell and R&R abbreviation in your post. It would be very useful to determine cost of other labour. Anyway
    Thanks a lot.
    (my engine is 3.2)
  • alcanalcan Member Posts: 2,550
    Mitchell Mechanical Labor Estimating Guide, probably the most widely used to determine labor charges. There are also Chilton, Alldata, etc.
    R&R = remove and replace (or re-install).
  • ghuletghulet Member Posts: 2,564
    Today, my '87 Honda Accord DX w/153k miles, appeared to be overheating (outside temp ~85, steam coming out of the grille). The temp gauge was in the middle, normal range. I opened the hood and saw radiator fluid (nice bright green water/coolant mix) that appeared to be leaking slightly out of the top of the radiator, or possibly from one of the connecting hoses. I drove it a few miles home in light city traffic, and the car sounded awful (not the engine, but the driveshaft was abnormal) by the time I arrived. I'm hoping the car didn't totally overheat and warp the heads or something. The car has a new radiator, so new coolant, and no fluids were leaking out to the ground.

    What does this sound like? I'm thinking/hoping thermostat, since the gauge was reading normal, which would likely have prevented the fan from engaging, and obviously there's a leak somewhere. Oh yeah, this car doesn't even have a/c, so that wasn't a contributor.

    Any help or educated guesses would be most appreciated.
  • zr2randozr2rando Member Posts: 391
    Sounds like there may be a hose clamp needs tightening, or maybe the cap..could also be the new radiator has defect/leak that just opened up.
    Being as the radiator is new, the work to put it in would be suspect.
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    The reason your temp gauge didn't work is that the sender cannot read when there is no water touching it. It can't read steam in other words. So you could have seriously overheated even in the gauge says no.
  • jc1973jc1973 Member Posts: 63
  • alcanalcan Member Posts: 2,550
    Thermostat, replace:
    302 (5.0L), 351 (5.8L)
    1.1 hours
  • yabadayabada Member Posts: 19
    Can you tell us all where to find the information that you have about the time needed to replace or fix something? The Mitchell webside doesn`t provide this info on line.
  • dunkmydonutdunkmydonut Member Posts: 35
    Hello , I have a 96 Ford van E150. I just took a look at the thermostat housing on my 5.8. I think most of the time stated for changing out the stat is for taking out the Air intake system. The housing has 2 bolts, holding it on. I had an old duster that would overheat in the summer. It got to where I would just take it out in the summer. No problem, I just kept it in a glass with antifreeze in it, so it wouldn't corrode. They claim you need a stat for emissions even in the summer. Luckilly my inspection date was Noveber. It got to where I could change it in 15 minutes. I sold it to a guy who still runs it [bless those slant sixes] and it's a 74. Just a piece of advice, I called 5 radiator shops and got 5 different prices.
    My last radiator I called for prices on ranged from 149 to 499 dollars. I picked the 149. Worked just fine till I sold it. The cheapest and most expensive were both made by the same company. Moen or something similar. I run rear wheel drive, not popular in New England, But that's what I learned on in the trades. I've driven front wheel drive, and they are much better in the snow, but I think I'll stick with the rear wheel drive.
    I worked on them since I was a kid. I like the sound of a V8 anyway. I know they have a few front wheel drive V8's, but they really looked crammed in. I don't mean to be disrespectful of anyone, but if you need a manual to change a thermostat, you might be better using the time to find out who's the better mechanics in the area, and do some price shopping. The bolts on the thermostat usually use a half inch wrench, and they're very easy to break off. That's true tightening as well as loosening. Sorry to run on, good luck to anyone giving it a try themselves.
  • alcanalcan Member Posts: 2,550
    Mitchell prints a mechanical labor estimating guide every year, covering domestic and imported cars and light trucks. It's about 6" thick and covers everything from AMC to Yugo. A friend works at a dealership which updates theirs every 2 years, and gets me their discards.
  • grishergrisher Member Posts: 4
    I bought '94 F-150 w/5.0 v-8 with 75K mi. in April. I've been having overheating problems since air-conditioning weather arrived. Cross-town driving coupled with sitting at a few stoplights causes temp gauge needle to go into highest third of range. Coolant can be heard boiling after I shut off engine. Couple times it has boiled a quart or more out of coolant reservoir. I've plunked down $500 so far at nearby Ford dealership, and problem continues. They replaced thermostat (I later noticed in maintenance book that previous owner replaced t-stat last August...I know, I'm a dope for not looking at the book before taking it in.) Next drained and flushed radiator and replaced radiator cap. Last time in they replaced cooling fan clutch assembly. Most recently I reduced my coolant/water mix in radiator to about 20 percent coolant, and I added Water Wetter product. Still boils. Any ideas?
  • swschradswschrad Member Posts: 2,171
    plugged radiator and bad water pump come to mind, but I hope somebody has used an exhaust gas sniffer at the radiator cap opening to see if the "boiling" has exhaust gas in it. if so, you got a head gasket problem, and you're already in serious trouble.

    if not, the radiator should be flow tested and rodded or replaced if indicated. hoses should be checked to make sure they are not going flat on you. I had a bad radiator cap that never allowed pulling water back in from the overflow, and that sucked my hoses flat, so if you see that, you now know what to do (your cap has been replaced, but doesn't mean they didn't get a bad one in the parts box.)

    if that doesn't do it, the water pump is a likely villain, and should be considered.

    how's the serpentine belt? if that or the pulleys are glazed, loose, cruddy, or beat up, you can't turn the water pump with the belt, and that causes the same issues. if you're fully instrumented on the dash, the battery charge indicator would not indicate charging with the a/c on and the lights on.

    it's a little outlandish to have dumped over $500 on the work done so far. if you've got an independent radiator shop in town, have them look it over next, the dealer has been missing something pretty obvious to this point.

    I'll bet somebody else's money it's either a gooped up radiator or the pump/and/or/belt issue at this point. the way ford makes those crimped aluminum radiators, if there are issues indicated there I'd just replace the darned thing.

    oh, yes... I am assuming you don't have a six-inch layer of bugs all over the front of the radiator, or anything else blocking airflow between the fins. doesn't matter if everything else works, no airflow, no cooling.
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