I have 2 sunfires...one is a 99 gt convertible automatice and the other is a 98 gt manual.
Both of them are having the same issue. If I am stuck in traffic or sitting at a light the a/c compressor cuts in and out (almost like it is surging) and the car begins to overheat. As soon as I start to accelerate the a/c kicks in and the engine cools down (it remains that way until I come to a stop again)
If I open the hood the coolant is boiling out of the top. Any ideas?
Do you know where the thermostat is and how to change it?
Hopeing for your sake that it is the thermostat, but it could be the water pump. The 2.4's have a water pump that is kinda prone to go out. how does your car run without the A/C running? If it does the same thing, it could be the pump.
98 Z24
RIP Specks
Agreed. The thermostat is the likely cause but if the pump is out, it'll cause the same effect. Or if something like mixing the wrong antifreeze together. Then you got a whole heeping of ("slap your momma") trouble.
Another thing is if the fan doesnt come on when it is hot, its not cooling the fluid in the radiator. Then this means that your temp. switch is out.
...They just HATE it when you ...POINT - LAUGH - then DRIVE OFF AND AWAY-!...
See your in the orange state ..where i'm in the whole crap it just dropped to dam it's cold province (Ontario) Canada where a thermos is the way to go ..here in below freezing time we let it warm up 15 mins before we hop in a themo is work are no work day ....ya I'd check it out .. Here everything freezes than summer rolls around and everything is worn out from hot and cold thermos and pumps seals etc your thremo should say on it 160* 180* i would go with a lower settting one check the pressure in the hose while its running and see if there movements of water that way you know the water pump is working and the thremo is opened ....worst comes to worst take out the thremo and runn it with out in hot temps....its only there to get your car to warm oparating temps..
sorry if i misspelled anything i just came back from the bar! ...but you get the jus of it ...
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Could someone explain to me how a mechanicly driven water pump with steel pump vanes "fails" without locking up or bearings making disgusting noises and stalling the engine? I fail to see how the steel vanes could suddenly stop pumping without something jamming them up, clogging them up, or breaking them off. The pump doesn't have a clutch or anything.
Sounds like a thermostat...it's only 5 bucks anyways and is supposed to be replaced every time the cooling system is flushed(30 months or 30k miles) which almost none of them are which leads you to thermo failure and radiator cap failure.
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'96 Cavalier Good ol' Pushrod 2.2
-24X,000 miles on factory build
-Some oil loss between changes, me thinks it be rings.
the a/c cycling on and off is a sign that the a/c compressor is overheating and shutting itself down. once you start moving, air flows through it and cools the a/c back down and turns it back on. that said, the a/c gets a majority of its cooling from the radiator fan. the radiator fan not turning on could also be the cause of your car overheating. i suggest you first start by turning your a/c on and seeing if your fan turns on. if it doesnt, start by checking the relay in the engine bay (swap it with the fuel pump relay, turn the a/c on, and turn the car to On but dont start it) and see if the fan runs. if it doesn't, it could be the actual fan that is bad. then from there, i suggest you start messing w/ the water pump and thermostat. its the easiest way to begin.
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- Sold my beloved J in April 2010 -
^^^^ X2 a oversight on my part yeah check to see if the fan is running
Could someone explain to me how a mechanicly <(mechanically)driven water pump with steel pump vanes "fails" without locking up or bearings making disgusting noises and stalling the engine? I fail to see how the steel vanes could suddenly stop pumping without something jamming them up, clogging them up, or breaking them off. The pump doesn't have a clutch or anything.
#1 A seal protects the water pump Impeller shaft bearing from contamination by engine coolant. If this seal fails, a weep hole in the water pump snout will leak coolant on the underside of the pump when this happens shaft failure will follow. Note that some weep holes are on top of the water pump .Ether bearing noise or bearings dislodging from the seats
To identify this Grab the water pump pulley and try to move it up and down side to side and if it moves the the bearing is worn out
#2 It's possible for a water pump to be bad, even if it doesn't howl or squeal or leak water. Some times the fins on the back of the impeller can corrode and wear down untill the pump is no longer effective. the only way to check for this is to remove the pump and check it
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If the coolant is acidic enough to corrode and wear down the vanes the waterpump shouldn't be the only thing you worry about failing.
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'96 Cavalier Good ol' Pushrod 2.2
-24X,000 miles on factory build
-Some oil loss between changes, me thinks it be rings.
It "shouldnt" be the only thing to worry about, but it can be a likely cause to it.
Looks heres your solutions 99GT:
1) Thermostat
2) Water pump
3) Cooling fan switch/temp. switch
4) Clogged radiator (unlikely)
5) Fan motor
6) Fan clutch
Hope it helps
...They just HATE it when you ...POINT - LAUGH - then DRIVE OFF AND AWAY-!...
OK, I'm the new guy here, but I know a little about cars.
Am I the only one to find the boiling coolant strange? I mean how hot does it have to get for a proper mix of anti-freeze to boil????
I suspect a bad mix or low pressure in the system. Just a stab in the dark.
Mike
97 Cav 2.2
I could be wrong, but I am 95% sure it only takes 212 degrees. The only reason it does not boil under normal conditions is because it is under pressure (in a sealed environment).
Remember, coolant is mostly water, with stuff in it to make sure it doesn't freeze and stuff to lube the water pump.
"The Blue Bullet"
Jon wrote:I could be wrong, but I am 95% sure it only takes 212 degrees. The only reason it does not boil under normal conditions is because it is under pressure (in a sealed environment).
Remember, coolant is mostly water, with stuff in it to make sure it doesn't freeze and stuff to lube the water pump.
That is the boiling point of plain water like in a pot on the stove. That is why I'm wondering if he has proper pressure. If the pressure is high enough the boiling point can be much higher.
Mike
97 Cav 2.2
David Jones wrote:If the coolant is acidic enough to corrode and wear down the vanes the waterpump shouldn't be the only thing you worry about failing.
Ok so what are you saying? Don't check the water pump.. Run out buy a Thremo and put it in and thats it?
It that what you do every time a problem comes up buy a part and hope its the right one?
"If the coolant is acidic enough to corrode and wear down the vanes the water pump shouldn't be the only thing you worry about failing".
^^^^^^Thats great shows me i have no idea of what I'm talking about or the 10 years of building water pumps for Hayward Gordon (google) it's called wear and tear combined with hard water(non- De-ionized water) and ethylene glycol
water pumps do wear and it was shown as a possible
Instead of thowing a word up. Used six times before your post. And riding someone elses coat tails did you metion how a pressure check might show him how it could be a leaking head gasket, Rad cap, etc? No. Lets say it was a failing thermo which it might be. Did you tell him the best way and cheapest way is to have have the car running and put his hand on the upper hose and see if its hot or feel for water movement? thanks your a big help !
99Gt things that might be needed anyways are a low-rad fluid check, hydrometer check , The antifreeze mixture should be atleast 50 percent but not more than 70 , maybe a pressure check Oh ya some mentioned check the fan clutch. There is no clutch on a electric non- belt driven fan
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My bad. I didn't realize that GM put so many different metals into their cooling systems making it common place for the metals to corrode in the system. I was speaking from experience where even after 300k miles on a diesel semi engine the pump itself looked fine even with the bearings shot to hell.
Plus you can deduct that pressure isn't the problem because it actually cools back down. If the coolant was constantly boiling in the block because of a lack of pressure it wouldn't cool back down. By that we can assume the radiator is ok, the cap is keeping pressure. We cannot say the thermo is ok and apparently can't say the pump is ok.
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'96 Cavalier Good ol' Pushrod 2.2
-24X,000 miles on factory build
-Some oil loss between changes, me thinks it be rings.
Ok on the other end i myself have a 2.2l with over 400,000 k and the water pump had gone on it. The bearings looked like new However there was alot of corrosion on the fins one of the fins had broking maybe lack the molding However this cause damage to the pump the rad was replaced 2 times before i owned the car . yes its unlikely to happen in 10% of all 2.2l but anything is possible and the hole point of posting a answer here is to help the person look at all options plastic, rubber, nylon., aluminium, steel, copper, etc mixed with water anti-freeze dirt, carbon, oil, gas. Theses thing DO react to one another and in time softer metals corrode and come apart. Adding to the part of the cooling system what has more contact with this the fins or the bearings?
Gm has used copper rads alum, plastic etc each for a reason...
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Plus you can deduct that pressure isn't the problem because it actually cools back down. If the coolant was constantly boiling in the block because of a lack of pressure it wouldn't cool back down. By that we can assume the radiator is ok, the cap is keeping pressure. We cannot say the thermo is ok and apparently can't say the pump is ok.
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Ok so theres pressure but is it in the hole system? isn't a working pump that causes the pressure? than why can't we say the pump is ok ?
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My bad. I didn't realize that GM put so many different metals into their cooling systems making it common place for the metals to corrode in the system. I was speaking from experience
Dex-Cool and Intake Manifold Gasket Class Actions
Girard Gibbs LLP has filed federal and state lawsuits seeking class action status concerning alleged Dex-Cool and intake manifold gasket problems in GM vehicles.
Consumers complain that a corrosive sludge-like substance clogs Dex-Cool equipped vehicles’ cooling systems leading to cooling system part failures, overheating, and internal and external coolant leaks. In particular, consumers complain of clogged radiators, heater cores, water pumps, hoses, caps, thermostats, and engine blocks.
Consumers also complain that certain intake manifold gaskets prematurely fail necessitating costly repairs.
General Motors has issued three technical service bulletins that relate to the sludging and intake manifold gasket problems.
If you've experienced similar problems with Dex-Cool or intake manifold gaskets in your GM vehicle, please let us know.
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Jimmaaaay! wrote:.........................................................................................................................................................................................
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Ok so theres pressure but is it in the hole system? isn't a working pump that causes the pressure? than why can't we say the pump is ok ?
Sorta, but no. The pump moves fluid. The fluid moves into a space already full of fluid, therefore, fluid moves because it can't compress. The pump just creates circulation.
The PRESSURE which we are talking about is from the expansion of the coolant. When the coolant heats, it expands and causes pressure.
"The Blue Bullet"
OK so i replaced the thermostat and still no go. Obviously I replaced the coolant and tested it out but it does the same thing. I turned the a/c on and again it would cut in and out. It was night time so the engine temp did not get as hot . Here is my other question, when is the fan suppose to turn on beause I had the car on for about 1/2 an hour and it never turned on? If it was the water pump wouldn't I have a lot more problems such as water leaking?
Try checking the fuse for the fan and see if it's blown. if it's not then try bypassing the relay for the fan or switching it with the abs relay right above it or that other relay above that, they are all the same, If that doesn't work try connecting the fan directly to the battery,
It's more then possible that the a/c cutting off is because the highside pressure skyrockets without the fan and it cuts off the a/c. The fan should ALWAYS be on when the a/c is going unless the car goes above what 35 or so. Apparently we were all wrong, I tend to think since I'd check a few things such as a fan that it's a given and forget that others aren't as experienced. Without the a/c the fan should come on when the temp is approximately 3/4ths thru normal.
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'96 Cavalier Good ol' Pushrod 2.2
-24X,000 miles on factory build
-Some oil loss between changes, me thinks it be rings.
