Car is over heating.... Please help!
09-09-2008, 02:28 AM
#16
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Join Date: Sep 2006
Location: Cliffside Park, NJ
Posts: 30
i had the same problem and it was the water pump. If you have checked the fans then the water pump is the problem. I really don't think it's the fans if it's doing it at highway speeds. I just had mine replaced by the dealer for about $600. It comes with a lifetime warranty too. Thats why I went with them.
I'll see if me and my friend can do, I really think it's the water pump also.
09-09-2008, 12:53 PM
#17
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I'm a little "miffed" on what would be failing on your waterpump? Its a very simple centrifugal pump & the impeller is directly driven off the shaft. If the pump (seal) is not leaking, I don't see how the pump could be bad? The impeller slipping on the shaft? Don't think so ~ the ones I have rebuilt (LT-1s)~ I've had a hard time getting the impeller off the press-fit shaft. Is your serpitine belt good? If its slipping, that could cause the pump to be under speed & get overheating? As for the radiator ~ jack the front of the car up, crawl under w/ garden hose & flush the rad & AC coil out directing the water from the engine forward. You can easily remove the electric fan assembly to gain access. You could also do it with a blow gun & air compressor.
09-10-2008, 12:57 AM
#18
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Join Date: Sep 2006
Location: Cliffside Park, NJ
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I'm a little "miffed" on what would be failing on your waterpump? Its a very simple centrifugal pump & the impeller is directly driven off the shaft. If the pump (seal) is not leaking, I don't see how the pump could be bad? The impeller slipping on the shaft? Don't think so ~ the ones I have rebuilt (LT-1s)~ I've had a hard time getting the impeller off the press-fit shaft. Is your serpitine belt good? If its slipping, that could cause the pump to be under speed & get overheating? As for the radiator ~ jack the front of the car up, crawl under w/ garden hose & flush the rad & AC coil out directing the water from the engine forward. You can easily remove the electric fan assembly to gain access. You could also do it with a blow gun & air compressor.
Also, check this out. I know when the engine is getting hot, because let's say I have the AC on, and i'm driving 55-65mph, everything's good. Then I pick up the speed and travel at about 70-90mph, and you see the coolant gauge rise, and it starts blowing warm air. But as soon as I hit 60mph, everything goes back to normal. ???? It doesn't make sense! I was thinking it can't be the pump, but then thought, maybe it's just wearing out? I hear people with similar stories, and they swear it's the pump. Is there a test I can do to see if it's shot?
09-10-2008, 10:13 AM
#20
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Join Date: Dec 2007
Posts: 117
I hear people keep saying its the pump ~ but I am at a loss to understand the failure mechanism of centrifugal pump if its not leaking at the seal? There is only 1 moving part (the impeller) and you cannot "wear" the impeller or the volute out. Short of starting the antifreeze holy wars ~ I'd stay w/ Dexcool. I'd change the serpentine belt to a new Goodyear Gatorback belt & clean the outside of the radiator before I go spending $150 on a new water pump.
09-13-2008, 01:44 PM
#21
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Join Date: Nov 2000
Location: Bergen Co, NJ
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Generally, overheating at speed is an indication of a flow problem in the cooling system or airflow to the radiator problem. At speed you are generating a good deal of heat and both the air and the coolant need to flow faster.
Let it cool down, remove the cap, then start it up. You should see the coolant running fast out of the small pipe at the neck. Once it warms up a bit, raise the throttle and you should see the coolant flowing through the radiator.
Make sure the air dam, is intact and there is nothing in front of the radiator (check from underneath).
Let us know what you find.
Let it cool down, remove the cap, then start it up. You should see the coolant running fast out of the small pipe at the neck. Once it warms up a bit, raise the throttle and you should see the coolant flowing through the radiator.
Make sure the air dam, is intact and there is nothing in front of the radiator (check from underneath).
Let us know what you find.
09-13-2008, 09:39 PM
#22
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Location: Akron, OH
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i bet u dont have an airdam. mine did the same thing b/c it didnt have one on it. put it on a few weeks ago and it hasnt gotten past 170deg in traffic. its a long black plastic piece...its what usually hits a curb first instead of ur front end.
09-15-2008, 12:06 PM
#24
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Join Date: Apr 2008
Posts: 53
Dumb question. Now if you don't bleed the system... why would it start to heat up at about 70-80 mph? Wouldn't it be the opposite? Like, shouldn't the car stay hot at idle if that was the case?
My car right now has a little over 81,000 miles. It sounds like a lot, and it is... but it's mostly highway. How would you clean the debris if it's blocking the radiator, because i have checked and it doesn't look dirty. How should I bleed the system, and is there a way to check to see if it is the water pump? My car runs great, but like I said, if I stay at 70 or 80mph it heats up, but as soon as I let go of the gas and hit about 60, it just starts to cool off. It's really pissing me off! Thanks for all the help so far guys!
My car right now has a little over 81,000 miles. It sounds like a lot, and it is... but it's mostly highway. How would you clean the debris if it's blocking the radiator, because i have checked and it doesn't look dirty. How should I bleed the system, and is there a way to check to see if it is the water pump? My car runs great, but like I said, if I stay at 70 or 80mph it heats up, but as soon as I let go of the gas and hit about 60, it just starts to cool off. It's really pissing me off! Thanks for all the help so far guys!
I'm sure everyone here is more experienced and would know better than me, but if you dont bleed your system correctly the air bubbles will get to the temp. sensor and cause a false reading showing its hotter than it is.
And I only have procedures for bleeding an LT1 but they should be similar.
Coolant Drain and Refill
Drain
Park vehicle on level surface.
Remove radiator cap (best to do this on a cold engine).
Slowly rotate cap counterclockwise 1/4 turn and stop.
Wait until hissing stops, indicating remaining pressure has been relieved.
After all hissing ceases, continue rotating cap to remove.
Open radiator drain valve Note: catch and dispose of used coolant properly.
Open bleeder screws 2 or 3 turns (protect the optispark from coolant).
Remove block drain plug on lower LH side of engine and knock sensor from RH side.
Allow system to drain completely. Alternate: You can put a garden hose in the radiator neck if you want to force clean water through the radiator. This may not force the water through the block if the thermostat is not open (probably won't be with cold water present). You can remove the thermostat to allow the water to more easily reach the block. Allow to drain after flushing.
Refill
Close radiator drain valve.
Install block drain plug and knock sensor (if removed during drain procedure).
If you did the alternate flushing above and have removed the thermostat, you might want to fill the block with your coolant mix through the top of the water pump before placing the thermostat back in. Some people report that this helps to lessen air pockets. Fill until the water pump remains full, install thermostat and water neck, then continue with the next item.
Using a 50/50 mix of coolant to water, fill the system through the radiator neck (bleeder valves open). You should hear a hiss of air from the bleeder valves as you pour in the coolant.
LT1 coolant capacities for the 4th gen F-body:
With Manual Transmission - 15.3 quarts (14.5 L)
(It's 12 quarts for an LS1)
With Automatic Transmission - 15.1 quarts (14.3 L)
Close bleeder screws when bubbles disappear and only coolant is visible.
Fill the coolant recovery reservoir to the COLD fill mark. This will provide the extra coolant required to replace the air left in the system upon the first couple of thermocycles.
Install coolant recovery cap.
Block wheels and run engine in Park or Neutral with the radiator cap off until thermostat opens (you should see coolant circulating in the radiator tubes).
With the engine running, add coolant to the radiator until the level is as high as you can get it. This may be tricky if you have an electric pump because coolant may try to gush out-be careful. Install cap sooner if coolant gushes out.
Install radiator cap.
Check for leaks after the engine is up to running temperature.
Monitor engine temperature. If the temperature goes up into the red zone, turn off engine and allow to cool. After it has cooled, check the level in the remote reservoir and correct if necessary. Open the radiator cap and check the level there, too. Run engine again until the thermostat is open and check again for air at the bleeder screws.
If, after doing work, you want to verify the coolant level for a few days, check that the level is to the top of the radiator neck when the engine is cold. Add coolant to top it off, if needed. Then, also make sure that the level is correct in the remote reservoir. Note: It is possible that the LOW COOLANT lamp may come on after this procedure. It should go out after the engine has gone through several heat and cool
Last edited by spltblkribbon; 09-15-2008 at 11:50 PM.
09-16-2008, 07:06 AM
#25
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Location: Charlotte,MI USA
Posts: 6,249
Mine would over heat while idling but sometimes when I went around 80 it would start to overheat too.
I'm sure everyone here is more experienced and would know better than me, but if you dont bleed your system correctly the air bubbles will get to the temp. sensor and cause a false reading showing its hotter than it is.
And I only have procedures for bleeding an LT1 but they should be similar.
Coolant Drain and Refill
I'm sure everyone here is more experienced and would know better than me, but if you dont bleed your system correctly the air bubbles will get to the temp. sensor and cause a false reading showing its hotter than it is.
And I only have procedures for bleeding an LT1 but they should be similar.
Coolant Drain and Refill
And just an FYI an air pocket around a temp sensor will always give a false low reading.
10-15-2008, 11:49 PM
#27
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Join Date: Sep 2006
Location: Cliffside Park, NJ
Posts: 30
Hey, I just wanted to say thanks to everyone that helped me out. It turns out that it really was the water pump. I went online (Ebay), to see if i can find a brand new one, they ranged from $185-$200 including shipping. I then asked my friend who works at a dealership, and he told me he can get me one for $180 with his discount. Just when I was about to call him to order one, I went down to Advance autos, and my buddy there, got me a brand new one, for $150! So, thanks again, and take care!
10-25-2008, 10:53 AM
#30
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Join Date: Oct 2001
Posts: 2,685
That is something to check, since it happens at highway speeds.
The pump can also be bad internally even if it is not leaking - the impellers can wear out or corrode and are less efficient - even the housings can wear.
People also overlook the rad cap, which can cause overheating if it wont hold pressure.
The pump can also be bad internally even if it is not leaking - the impellers can wear out or corrode and are less efficient - even the housings can wear.
People also overlook the rad cap, which can cause overheating if it wont hold pressure.