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Chevy Venture Engine Problems

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Comments

  • msargent76msargent76 Member Posts: 1
    I have an overheating problem with my 2000 Venture also. I have replaced the water pump, thermostat, changed the radiator cap to a vented one in case it overheats again, flushed the system, and when that didn't work, I clean out the system and used blue devil for the head gaskets. The radiator is building tremendous back pressure that backs up into the reservoir when it gets really hot. If you look down into the radiator while it is running, you can see a little rust circulating in the new antifreeze, so I know there is sludge down in the system, how much? I don't know. At an idle, the radiator starts pumping water out where the radiator cap would be, but if you increase the RPMs the water sucks back down into the radiator and you can see the vents in the radiator circulating. The thermostat checks out fine, fans are fine, circulation flows through the water pump and out to the radiator so water jackets seem fine in the engine. Could it possibly be the catalytic converter clogged with the sludge? I'm at my wits end! :confuse: :sick:
  • AJGWHEELSAJGWHEELS Member Posts: 10
    you need to purchase a Special GASKET KIT design for VENTURE , its by VICTOR FLINTZ ( hope I got the name right) if it was never done , you need to replace the PLENUM GASKET & THE EXTERIOR GASKET & the rest of the kit parts that come along so you can have Piece of mind , If your good with tools then
    buy the HAYNES REPAIR MANUAL for this vehicle , it should take about 2 to 5 days to complete this project. AJ
  • james1967james1967 Member Posts: 1
    this issue sound similar to mine, i have 98 venture ..had a head gasket changed, after it was overheating, found hole in the gasket.. now the engine seems ok except there is air or pressure in the hoses.. the the needle stays low, except for idle.., i took it in and mechanic fiddled with the relay fuse and put another used one in, and the engine check light went out and the pressure was fine, until i took it on the road for a test..after i gave it some gas couple times..the engine light returned with a little power loss on the accelerator and pressure came back in the hose again and remains that way.

    this issue is kind of screwy,;mechanic said pump is working but he didn't test it and i changed a new thermostat before i got the head gasket changed (prior), ( used a stop leak product for the rad before i changed head gasket also) there's no leaking of fluids and nothing contaminating the oil, rad been flushed too.
    Only other thing i can think of is the AC light stop working short time ago and couple other electrical issues hasn't worked for a longer period.
    and when i accelerate putting more load on the engine..(like up hill) the check engine light flashes and power is reduced on the accelerator.
  • ace14uace14u Member Posts: 1
    Hey everyone,I have a 99 venture check engine light comes on so I check it and got the codes p0171 p0300
  • 442dude442dude Member Posts: 373
    edited July 2010
    Try this: replace your PCV valve and make sure that the hose is in good shape...

    I got the same 2 codes on ours and that was the fix...I can't guarantee it will fix yours but its worth a $5.00 try...my mechanic couldn't even figure it out, a friend suggested it and it worked...
  • fleastifffleastiff Member Posts: 52
    About how much would replacing a PCV valve and hose cost?
  • bwaymirebwaymire Member Posts: 1
    I know mini vans are not racers, but I'd like a little tighter ride in my Silhouette. Would the struts from a Montana be better, or are there any other suspension options?
  • 442dude442dude Member Posts: 373
    Talk to your local auto parts guy. He can check right in their catalog to see what fits and tell you which ones would be stiffer and would fit your van. There aren't a lot of options but there are likely a couple.
  • 442dude442dude Member Posts: 373
    You're under $ 20 for both at your local auto parts store
  • phisher0420phisher0420 Member Posts: 2
    My venture is starting rough or taking 30 seconds or more to turn over. I pulled battery and it is fine. What can it be next?
  • hido4hido4 Member Posts: 1
    have a loss of power/acceleration on steep hills but goes like hell on the level and/or downhill? what say somebody that knows chev venture 2003 mani80@netzero.net
  • jrumleyjrumley Member Posts: 3
    I have a 2002 venture. If it idles it slowly goes to red, driving, after five minutes. When in red, heater blows barely warm. The radiator cap and top of engine just warm. In red the engine will preignite and stall. Once stalled it has to sit for fifteen minutes before it will start again. When this happens water vapor comes out of the air cleaner box and water droplets are on the surface of the maf screen.
    I have taken out the thermostat, vented the cooling system. I have taken it to a radiator shop, they are not sure. No exhaust gases in radiator. Where is the water vapor coming from. Could it be a bad manifold gasket? Thanks
  • davy2davy2 Member Posts: 3
    With you vehicle running open the hood and check to see if both cooling fans are running. If not turn on your A/C and check again. There are 3 resistor switches inside the fuse block that drive the cooling fans. Turning on the A/C overrides the temp sensors
  • jrumleyjrumley Member Posts: 3
    Thanks for the reply. The fans are working and sounds like the correct speed.
  • jrumleyjrumley Member Posts: 3
    Iam the previous owner of the above problem,but. I found it. I pumped up the cooling system to fifteen pounds. Hissing came from the intake manifold near the throttle body. This is critical, since lower cooling system pressure the lower the boiling point, check it out. Anyway, will order the manifold gasket kit from GM.

    Tha
  • awil28awil28 Member Posts: 13
    Hey everyone, im hoping i could get a little insight on a car im working on. I purchased the car and the seller told me it had started overheating and acting like the head gasket was starting to go bad but not blown, there was never any oil-coolant contamination, and he gave me the full gasket set for the engine with the car. I drove the car home, had to stop twice to add coolant because it was all pouring out the coolant overflow, and then tore the engine down. The head gaskets did not look that bad, the lower intake gaskets looked ok, and the upper intake gaskets looked like crap. I replaced all of them since i had them, also replaced the following, spark plugs (gapped .060), plug wires, thermostat, coolant resevoir lid, power steering pump, valve cover gaskets, pcv valve, throttle body gaskets, exhaust manifold gaskets and bolts, fuel injector o-rings, air filter, and oil/ oil filter. After i did all this i put the engine back together and started it up, it started right up but is not idling smooth and also is still spitting all the coolant back out the overflow. Ive flushed the system and burped it 3 times for 45 minutes each time and it still does it. I also ran a compression test and got 130psi from 5 cylinders and 120psi on the #5 cylinder those numbers sound low but im not sure what they are supposed to read. Also the small vacuum tube connected to the pcv valve is collapsing when the engine is idling and the engine seems like its stalling out. Ive had suggestions that the heads where warped and now i need to redo the head gaskets, the heater core is bad, something is wrong in the vacuum system, and the water pump is bad. So with all this info can anyone tell me what it sounds like im hoping i dont need to redo the head gaskets but that looks like where its heading. Thank you to anyone that helps.
  • awil28awil28 Member Posts: 13
    Hey everyone, im hoping i could get a little insight on a car im working on. I purchased the car and the seller told me it had started overheating and acting like the head gasket was starting to go bad but not blown, there was never any oil-coolant contamination, and he gave me the full gasket set for the engine with the car. I drove the car home, had to stop twice to add coolant because it was all pouring out the coolant overflow, and then tore the engine down. The head gaskets did not look that bad, the lower intake gaskets looked ok, and the upper intake gaskets looked like crap. I replaced all of them since i had them, also replaced the following, spark plugs (gapped .060), plug wires, thermostat, coolant resevoir lid, power steering pump, valve cover gaskets, pcv valve, throttle body gaskets, exhaust manifold gaskets and bolts, fuel injector o-rings, air filter, and oil/ oil filter. After i did all this i put the engine back together and started it up, it started right up but is not idling smooth and also is still spitting all the coolant back out the overflow. Ive flushed the system and burped it 3 times for 45 minutes each time and it still does it. I also ran a compression test and got 130psi from 5 cylinders and 120psi on the #5 cylinder those numbers sound low but im not sure what they are supposed to read. Also the small vacuum tube connected to the pcv valve is collapsing when the engine is idling and the engine seems like its stalling out. Ive had suggestions that the heads where warped and now i need to redo the head gaskets, the heater core is bad, something is wrong in the vacuum system, and the water pump is bad. So with all this info can anyone tell me what it sounds like im hoping i dont need to redo the head gaskets but that looks like where its heading. Thank you to anyone that helps.
  • jimmie60jimmie60 Member Posts: 1
    I have replaced the thermostat on my 1998 Chevy Venture and filled the coolant resevor; however, the car still is overheating. I have checked for leaks and have found none. Any suggestions on what could be the problem? The thermostat does not seem to be opening up at all.
  • driftersdrifters Member Posts: 1
    98 Chevy Venture overheated replaced thermo,hoses,& rad. cap.. Still don't seem right heater blows cool then hot then cool again what the problem? :(
  • russ23russ23 Member Posts: 25
    Had all that on my engine. I am presuming you did not install thermostat upside down and that it ran hot even without the thermostat. Consensus of IATN (major mechanics website) is blown headgasket. You check that with block tester abt $50 at NAPA. Install in radiator cap opening and check for change of fluid color. You might be able to fix it with just the intake gasket set, but that is a gamble. A word on anti-freeze. I do not like the DEXCOOL GM uses. Turns to mud and clogs everything up and there is no good cleaner to clean it out. If you know one let me know. Also possible the radiator is clogged up with DEXCOOL mud. No way to clean it out, have to replace.
  • phisher0420phisher0420 Member Posts: 2
    i have a 2000 venture that needs a new thermostat. Wheres is it and is it hard to change?
  • russ23russ23 Member Posts: 25
    Thermostat is under the throttle body assy (driver side facing the engine). Look for the radiator hose follow it to the block. It is contained in a aluminum housing. To get to it remove air cleaner hose. Book says you should be able to get to it that way, but I doubt it. May have to remove the upper intake manifold. If you want to change thermostat because of an overheating problem, that may not fix it.. Main cause of overheating on this engine is leaking cylinder head and/or intake manifold gaskets. If cylinder head gasket, it is probably cheaper to get another engine from junkyard, that is what I did. To test use a block checker (bulb with colored fluid). Insert in radiator cap opening, with engine running sample air in radiator. If fluid changes color you have a cylinder head gasket leak into the coolant which causes overheating. If no change in color, go for both upper and lower intake manifold gaskets.
  • bob_d1963bob_d1963 Member Posts: 1
    If I am not mistaken, the thermostat will only fit in one way.
  • russ23russ23 Member Posts: 25
    Not sure if you can install the thermostat incorrectly. I presume the basis of the question is that you installed it and not sure you did it correctly!!! If so you might be able to remove the radiator hose and maybe look inside. Better not see the thermostat spring!! If engine is still overheating, I would recommend pulling the thermostat entirely and running engine without it. If it overheats then the above problems are the cause.

    Thermostat must always be installed so the spring/capsule is inside the engine.

    MURPHY's LAW is usually in operation and if it can be done wrong it is highly likely you will do it the wrong way!

    It is best to remember how the thermostat works rather than depending on how it looks to install it correctly. Thermostats are always mounted in the water OUTLET end of the engine that moves water to the top of the radiator. The water pump is the INLET/SUCTION side and it draws water from the radiator bottom (cooler water because heat rises). Purpose of thermostat is to restrict water flow in the engine until the engine heats up. When water temp gets hot enough the heat capsule weakens up and allows the spring to open the thermostat valve. IF THE CAPSULE/SPRING IS NOT ON THE ENGINE SIDE THE CAPSULE CANNOT BE HEATED. By the way I have been there and installed the thermostat wrong because I was looking at how it looks rather than how it should work.
  • josechilljosechill Member Posts: 3
    Hi
    I have a 98 chevy venture. my problem is overheating. I change the thermostat,thermostat sensor & waterpump but she still overheats. I've read everybody commets and answers but i haven't read about the fans.
    My fans don't turn on when the car is hot. I turn on the ac and then it turns on.
    But thay turn off after a while and then she starts to over heat again. only when
    she gets real hot the fans may kick in. Dose anybody out there ever notice this
    and is there a solution for this fix. Can someone help.
    I love my car and i don't want to get rid of her.
    Thanks to all of you.
  • russ23russ23 Member Posts: 25
    I wished I could make easy for you but it isn't. No silver bullets here. I have a complete set of factory service manuals for my 1998 Venture and troubleshooting this problem is over a dozen pages. You might have to bite the bullet and go to the dealer and at least pay for the diagnosis rather than wasting more money throwing parts at it. The fans are controlled by the engine computer based on input from the engine coolant temp sensor (and probably other sensors as well). All those can cause the problem to include wiring. You did not mention messing with the coolant relays? These are the usual problem.

    Note: fan position is from drivers seat, so it is reversed when looking at them from the front of the van.

    Under the hood over the battery is a fuse box. Fuse #6 (30amp) powers the right/low speed fan you say does not come on (w/o A/c). Check to make sure it is okay. Also check fuse #1, which controls the other left/high speed fan (in case I get this mixed up). Presuming they are both ok relays #9,10 and 12 (gray color?) control both fans. They are all the same but #12 (by itself) controls the right/low speed fan. I am guessing it might be the culprit. Pull #9 and install it into #12 (leave #9 out). Nothing will happen until the engine overheats, so go for a short ride. If the fan then comes on the relay you pulled is the problem. If it still does not come on, (with engine running) pull the relay and use a digital voltmeter on 20 volts dc scale and test cavity #30 (one probe there and one to ground) for power. If you get power that relay is also bad, if no power you might want to call a priest because it gets real tough now. The problem is in the engine computer or another sensor/wiring or what the hell. It could be anything. Good Luck. Don't you just love cars!!!!
  • russ23russ23 Member Posts: 25
    This is let everyone know that you can pull the engine out the top and do not have to drop it from the bottom. I have pulled my 1998 three times out the top so I know what I am talking about. Too long to tell you but if you email me at lloydballard@hotmail.com, I will be glad to send you might experience. It is pretty straight forward. Key is to just rope up the hood to protect the windshield (do not remore). Remove the windshield wiper assembly as one piece with the arms (6 screws under the plastic apron). Then remove all the junk like cruise control, battery, upper intake manifold, all exhaust manifolds, etc. You will then see there is plenty of room to pull out. I used a cheap cherry picker. The key is to use a chain stretched tight against the block so you have room to lift with the nose of the cherry picker. Anyway, it is not magic. I have pulled a half dozen different chevy engines and this is the easiest. Astro van is the hardest.
  • darangodarango Member Posts: 1
    I had the Intake gasket replaced about 6 months ago. Yesterday i had the water pump,and the Thermostat changed. but still getting high back pressure at the Radiator cap,and a jumpy Temp Gauge.
  • russ23russ23 Member Posts: 25
    Sounds to me the cylinder head gaskets are gone and allowing combustion gas to heat the coolant. Remotely a clogged radiator. To be sure you need to perform a block test. Sold at most parts houses and definitely NAPA it is turkey baster type tester you stick into the radiator cap opening and watch change of color in test liquid. If it changes from blue to yellow you have blown cylinder head gasket. If you have high miles, I would recommend used engine instead since heads can be warped from heat and bearings could be worn out or getting ready to go.
  • david357david357 Member Posts: 1
    I have a insurance adjuster company we have 6 chevy ventures bought new or with low milage. They are awful each week I am spending 200 to 300 dollars to keep them running. I have overhauled the entire cooling system. Nothing works, Chevrolet should be ashame selling such bogus version of a van. If you have one sell it quick before something else go wrong
  • jeanzjeanz Member Posts: 1
    Haven't had this issue with Venture but other GM vehicles would overheat then cool down with heater full blast. With these vehicles a thorough radiator flush completely solved the issue, also with these vehicles the flush was an annual event, at 13 months all would over heat again.
  • smoringsmoring Member Posts: 1
    Just out of curiosity, if you let the engine cool down to the point where you can remove the radiator cap, shouldn't you see fluid moving from the upper radiator hose (furthest from cap on top of the radiator) through the cooling fins back tot he lower hose once the thermostat opens?

    I don't see any fluids moving on mine, my thought is water pump and/or thermostat. The top radiator hose gets warm but not hot, and the lower hose is ice cold. Only takes about 2-3 minutes for the engine to go from zero to 50%, then another minute to get to 75% of the gauge.

    Thoughts?
  • wintersetwinterset Member Posts: 4
    First,

    IMO, there is no issue with Dexcool and sludge. the "sludge" is an supplement/additative GM added to the coolant as "insurance". it's basically ground walnut shells, and ginger root. Cast aluminum is pourus, and this can seal up any micro leaks. this will easily pass thru any coolant system, and when it does, it'l be ground up by the water pump. when exposed to air, the mixture turns to a jelly like rubber sealant.

    Second, I would suggest anyone that suffers from the cold coolant in the overflow, or temperature fluctuations, cold heet in cabin to have their thermostat changed, but have a 1/8 hole drilled into the outer portion of the t-stat. (between the thermo mechanism, and where the rubber gasket is. seems the 3.4 does indeed suffer from HG issues, but it is made worse by the fact that when the thermostat is closed (on a cold engine), or a running engine that's moving down a cold highway where the thermostat closes for some time. what happens is that tiny amount of air bubbles (less than a cup full) float up to the thermostats thermo sensor, and prevent the thermostat from properly detecting the temp of the coolant!. it varies, because if you make a turn, are on a bouncy road etc, the coolant will splash up & sometimes open the stat enough for you not to overheet, but you will see it on yor gauge as fluctuations. by drilling a hole, your 3.4 will indeed maintain it's 195 degrees, BUT any air trapped under the stat will be forced up to the highest point in the coolant system (luckily the cap), and as the pressure increases, it will be slowly expelled without damage to the overflow tank. Sometimes, small amounts of coolant will be dripped into the tank as well (even happens with a healthy engine), but during normal driving with acceleration, some of you know that the cooling system has a vaccume where it sucks in. - seen by a radiator hose collapsing a little or getting soft on a hot engine. - the good news is that the hose in the overflow tank is submerged in coolant, and it will suck that in, and not the air. as the pressure in the cooling system gets to operating temps, and 15psi, the amount of exhaust gases squeezed into the system diminishes. DO NOT USE HG IN A BOTTLE. you fill screw up the entire cooling system.

    BTW, many cars have self purging systems that resolve this issue unfortunately not the 3.4 we must make it ourslves.

    GOOD LUCK
  • willy30willy30 Member Posts: 2
    Hi, I've recently had the intake gaskets replaced, 200,000 kms/162,000 miles. I was smelling the coolant in the cab and could see some leaking on the engine. Works great, like new except there is a reduction of fuel mileage from 33-34mpg to 29-30. Mechanic does not have any ideas.
    Anyone out there encounter same?
  • neustkgneustkg Member Posts: 35
    Wow! How were you getting 33-34mpg? At best on the highway we got something like 30-31mpg but that was when we were keeping the speed between 65-70mph. We drive across Wyoming and Idaho once a year and since the speed limit is 75, we keep it between 75-79 and get an average of about 27-28mpg (which makes sense due to the higher speeds) depending on the wind. You pretty much have to drive at least 75 or you get ran over by semis (hypermilers would be in danger on these highways).
  • willy30willy30 Member Posts: 2
    I have to clarify that I was doing 60 mph most of the time, on repeated long trips and this is in Imperial gallons, which are larger than U.S. Gals., also using nothing but Shell gasoline. Alas I can't seem to recover my former fuel mileage.
  • kellermeierkellermeier Member Posts: 1
    I might of found a very effective way of ilemminating the air pockets in the cooling system with out opening the bleed off valves all the time. My daughter has a 2002 Venture and has been having problems with over heating and no heat for defrosters or interior of the van. A mechanic changed the thermostat, but problem remand. Everytime we bleed the cooling system, it would go away for short periods and we had heat in the van. I had an idea, thinking of the old cast iron radiators in homes with the pressure relief valves, these are closed loop pressurized systems, and they had automatic bleeders to remove any air pockets, so why wouldn't this work on the van. Well, I found one thru a McMaster catalog for $26.78, Installed it and right away it started working as thew van should of. The valve is made by Maid-0-Mist and is called Auto-Vent No.78. All you have to do is remove the total bleeder assembly on the passenger side of the motor, and screw the automatic bleeder valve with the 1/8" NPT valve body directly into the bleeder port. Done, about three minutes and no more overheating problems and instant heat/defrosters in the van again. Doing research, it looks like you can order these automatic air eliminators right from your friendly Ace Hardware stores for a cost of $10.00 to $15.00 dollars.
  • ckelley1ckelley1 Member Posts: 1
    Does anyone know the true answer to this problem???
  • wintersetwinterset Member Posts: 4
    WOW KellerMeier - that's great you got this going. I am curious how this works out in the long run. I just did a Head gasket job on my Venture, and the gasket was intact, but the head had a small warp that the machine shop milled out. I'm sure your solution will work for many 3.4's that have a very minor amount of air entering the coolant - that reaks havic on the ability of the water pump to move the coolant thru the block. aside from the 1/16 drill hole in the stat, I also thought of using a 180 degree stat to keep the block 15 degrees cooler, and thus reduce the amount of expansion on the aluminum heads. Unfortunately because of emissions standards, it will be hard to find anyone who will match up a 180 to a 195 & sell it to you.
  • russ23russ23 Member Posts: 25
    What problem?
  • wintersetwinterset Member Posts: 4
    Yes. I know.

    The 2 heads are aluminum & the block is cast Iron & each has a different rate of contraction & expansion. the head gaskets are made of multi layered steel (MLS). If the cooling system is not maintained properly (not kept full, car allowed to overheat etc.), air is trapped in the cylinder heads, and form hot spots, and the expansion/contraction is made worse. additionally the head gaskets themselve (steel), can begin to rust. All that is needed is a little leak between the cylinder portion of the gasket, and the coolant portion of the gasket, and you will get air pushing into the coolant.
    think of it like this oIO where "O" is the cylinder, and "o" carries coolant thru to cool the engine block. if "I" rusts and breaks down, compressed air from "O" can now get into "o" and causes the car to overheat.
    best advice if your Venture is OK is to keep that overflow tank filled to the line with 50/50 dexcool. If you have to keep filling it up, you have a leak, and you really should get it fixed. - these vans are really reliable if taken care of. Unfortunately for those of you who purchased 2nd hand, you have no trustworthy way to know how it was maintained. everything on this van is simple and straight forward.
  • fred150fred150 Member Posts: 1
    Not calling you a liar as much as i'm calling myself stupid..If someone can be kind enough to explain i sure would be appreciative..The maid o mist thing is designed to vent at 75 psig and the radiator cap does the same thing at 15 psig or a whichever one it is.Soo how can the maidomist vent before the caps does??
  • davet_1961davet_1961 Member Posts: 5
    Here's my experience with the 98 venture I own. After a year of overheating issues I replaced everything in the cooling system. Here's the list...radiator, hoses, heater hoses, engine coolant temp. sensor, relays (all 3) maf sensor, egr valve gasket, thermostat, water pump, upper and lower intake manifold gaskets (twice), the upper intake manifold (try finding one of those in a junk yard, tons of engines without the intake manifolds on them) and rebuilt ecm. After replacing all this the first few times it overheated (according to the gage) I 'bout blew my top. I took it to a reputable shop and has them diagnose it. They checked the block for minute cracks (none) and then let the engine run for 4+ hours to check the temp. It never overheated but the gage showed it running hot. The official verdict was this, since the coolant temp sensor AND the ecm were new, the sensor wasn't correctly calibrated so the ecm was reading that the engine was hot. Temp at the sensor was 225% when the fans came on. Runs great now, I just don't worry about the temp gage until I see steam!
  • fleastifffleastiff Member Posts: 52
    How long should a radiator and water pump last?
    2002 Chevy Venture runs hot all the time and recently got well into the Red zone.
    Mechanic says its needs a new radiator and water pump but he did that 4 or 5 years ago.
    Is 500.00 a fair price for this job?
  • russ23russ23 Member Posts: 25
    There is no magic timeframe for radiator or water pump life. Pull radiator cap and look at the seal and inside of the radiator. If it is muddy brown, that means your anti-freeze has gone bad. The GM a/f is Dexcool and has a habit of turning to a brown (acid) sludge if not changed frequently. Changing it does not fix overheating since the damage is done with the muddy a/f that gums up everything and eats cylinder head and intake manifold gaskets. To make your life more challenging, there is no known cleaner to clean the coolant out of your car. EPA has eliminated most of the heavy duty cleaners. The most common cause of overheating is failure of the cylinder head and/or intake manifold gaskets. So just changing the radiator/waterpump may not fix the problem. A cheap way to tell is to pull the thermostat and run the car and see what happens. You need to do a block test to check for combustion gasses overheating the coolant. That tester is $50 at NAPA (turns a blue liquid to yellow if you have a cylinder head gasket leak. If you are losing coolant, this may be your problem. Of interest, how does your heater work? A dirty radiator also means a dirty heater radiator. That small radiator acts as a filter and it clogs easily.
  • ybkybk Member Posts: 1
    Here is the technical discussion on throttle position sensor (TPS) and high idle.
    When throttle is closed Powertrain Control Module (PCM) sees about 0.5 (plus minus 0.2 or so depending on a particular sensor) Volts. When ignition is turned on PCM records the voltage as 0% throttle.

    If TPS is worn out or wires are loose the voltage may drop below initially recorded by PCM and PCM will assign 0% to a lower voltage, for example 0.3 Volts. As a result the original voltage of 0.5 Volts is interpreted by PCM as 4% open throttle, enough for PCM to start thinking that throttle is partially open and stop idle control loop completely.

    Check engine light goes on only when TPS voltage drops below 0.2 Volts or so.

    I was only able to figure it out after borrowing a professional scan tool and monitoring sensor data while driving.
  • dmosserdmosser Member Posts: 4
    Hello eveyone, just wanted an opinion from all you experts about why my transmission still seems to slip after just getting a rebuilt one put on. Literally within 1 week of rebuilt one put on, same issue back again. Van has 143k on it and tranny has felt like its slipping past 3 years. Before new tranny it was slipping getting on ramp on hwy and then at 60-70 speeds. Now its slipping on hwy again AND in town since new tranny put on? Any ideas here are greatly appreciated.
  • russ23russ23 Member Posts: 25
    The obvious answer is to take the car/trans back to the company that rebuilt it and say fix it. I am not a trans guy, but I own a 98 Venture with 165k and the trans runs as good as the day it was installed. I am not the original owner, but the previous owner did do maintenance on it so I presume the trans was serviced. I had the trans serviced at 140k. The engine is another story, it is the second one that died at 135k.

    Here is my thinking. It just so happens the trans in the van is UNIQUE only to 1997 and 1998. It is called a GM 4T60-E transmission. You might want to google Wikipedia 4T60E. It gives a lot of good info that might be relevent to your situation. A key issue here is that trans came in 12 different combinations and it is possible the wrong parts were used. You say your trans was rebuilt. Does that mean the original trans was rebuilt or they exchanged it with another that was supposedly rebuilt? It makes a difference if they installed one of the other 11 different trans into you car. Another thought is in 1999 the trans was changed to a 4T65E. Not sure but remotely possible one of those was installed and it was not intended to work.

    Since the trans has the same problem of the original, it is highly likely they just screwed up in the fix especially if they did not change out the torque converter.
  • destiny6destiny6 Member Posts: 1
    I purchased a used 2002 Chevy Venture last year. It started leaking water into the floorboard and then overheating. So we changed the heater core. The problem got worse. So we changed the thermostat, and found that the water pump was leaking so we changed that too. The overheating got worse. The leak in the floorboard got worse, so we changed the heater hoses and found that one of the clamps was bad allowing water to leak into the floor boards. We did a compression test, and it has good compression. However, we cannot drive it for more than a mile without it completely overheating. We cannot figure out what is going on please help. Also I don't know if this is relevant but the heat does not work either.
  • russ23russ23 Member Posts: 25
    Continuous loss of coolant has probably caused engine to overheat to point of no return. Might possibly get by with replacing cylinder head gaskets and intake gaskets. Overheating on this engine very common problem. A used engine from junkyard probably a cheaper fix. I attempted to repair my 1998 Venture with new cam bearings (cam failures also a problem) and when thru it started leaking oil. Ended up with a junkyard engine that cost less to replace than the fix. Have been happy ever since.
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