First off let me say, Thank You in advance.

2002
Chevrolet
Cavalier
2.2 L
56,000 miles

I have a problem with overheating, last week I was driving home with the A/C on and the car just started to overheat (Never had problem before). Shut it down and towed home, changed the thermostat (180 Degree). Same problem, temperature just keeps climbing. Changed the water pump and serpentine belt. Same thing, Keeps overheating. Flushed the entire system out, Heater core, Radiator, Took the Reservoir tank off and flushed it, Hoses....anything I could find. Put all new 50/50 mix back in. Cycled it a few times and checked the level. Started driving it with the heater off car ran normal (195-200), turned the heater on and the temperature started to climb, 215, 220, 235... I turned the heater off and continued driving about 35-45 mph and the temperature dropped back down to 195-200. Now I don't have a full head of hair , But now I have even less from pulling it out. I have bounced this off several auto mechanic friends and they came up with I need a new reservoir pressure cap (Done), I need to burp the system (Done), Etc, Etc..... PLEASE HELP.
Anything you guys can come up with will be appreciated. By the way this is the first posting for me here, and if i posted in the wrong section I apologize.

One this one considering every thing you've done I would probably confirm that it is actually overheating. Does it seem like it's getting hot, any obvious signs?

If you have access to a scanner, compare what the computer is seeing to what is registering on the gauge. If not, use a temp gun around the T stat housing and see what kind of a reading you are getting..


(This post was edited by Sidom on Aug 30, 2009, 5:59 AM)

Put the OE thermostat back in asap! 180F is just as open as OE at 195F so that was a foolish move and confuses the car.

Use an infrared thermo if needed to see where heat goes or doesn't,

T
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Tom Greenleaf - MetroWest, Boston

Have you checked the coolant level to determine if it's lost any coolant?




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Tom, I looked this up in chilton's, and 180 is OE according to them. Also, I threw the old thermostat out. Can you explain what you mean by confusing the car? (UPDATE) ...I drove the car this morning for 30 minutes (outside temp 65) and the temp stayed around 195-198. Put the heat on and it started climbing to about 225 or so. Coolant level was perfect before test. Just checked it now that it's cooled down, still good. Oil level has not changed. Could it be a bad heater core? I really can't afford to keep changing parts without cause. I've read some of the responses on this site and you guys are very clever in your thoughts. I'm crossing my fingers for the "MAGIC" answer.

"Notes: 180 degrees Original equipment temperature. " ******************************** Egad! I stand corrected! 180 was OE and my fault entirely. Many for decades have been 192-195F and lowering that doesn't solve an overheat problem. If a car was designed for the higher temp it can think it's too cold and make wrong adjustments - not the case here. Now it's back to basics. Why did it overheat to begin with? From that you need know if all air is out - not just the recovery tank, and proceed with diagnostics for usuals like no fan or at worst a head gasket issue. Try to avoid replacing parts as a solution, both costly and screws up a diagnosis IMO. Can you feel heat blowing off radator? Also - can you verify if it's really overheating or just bad info?? Sorry for the mistake in OE temp spec., T
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Tom Greenleaf - MetroWest, Boston

I'm not sure what your reading but this car takes a 195 thermostat.

The electric fans don't even come on until 223 degrees. In slow traffic, 225 to 230 is acceptable and normal




78 Corvette Pace Car For Sale-18k mi orig-Florida

Crap! That's what AutoZones parts said!! WT hell do I know? If there's a mistake in all that it sure isn't helping the fix!

Folks used 160s and 180s in boats TMK NOT cars!

T??
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Tom Greenleaf - MetroWest, Boston

You know, I'm finding that in the application catalogs too but I find it hard to believe. I don't think an 02 car can pass emissions with a 180




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Cooling System Description and Operation

Cooling Fan Control
The engine cooling fan system consists of one cooling fan and one relay. The relay is powered by the battery positive voltage circuit and controlled by a switched ground from the powertrain control module (PCM) .
During operation, the PCM supplies the ground path for the cooling fan relay through the cooling fan relay control circuit. This energizes the cooling fan relay coil, closes the relay contacts, and supplies battery positive voltage from the cooling fan fuse through the cooling fan motor supply voltage circuit to the cooling fan. The cooling fan motor is grounded through its own ground circuit.
The PCM commands the fan on under the following conditions:

• Engine coolant temperature exceeds approximately 106°C (223°F) .
• A/C refrigerant pressure exceeds 1310 kPa (190 psi) .
• A/C is requested and vehicle speed is below 100 km/h (62 MPH) with A/C pressure above 1413 kPa (205 PSI) .
• Vehicle speed is less than 8 km/h (5 mph) for more than 750 seconds. The fan will turn off when vehicle speed is greater than 8 km/h (5 mph) for more than 20 seconds.

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Tom And Hammer, I just checked with Hanes repair guide and it backs-up Hammer's point of 195 degree for 2.2 OHV. But, it also says 180 for a 2.2L OHC. Now, when I went to Advanced Auto they asked for the 8th letter of the VIN which is a "4" which I was told means I have a 2.2L OHC which calls for a 180 thermostat. Now, I also must say that the car always ran about 195 (according to the dash gauge)before this happened. And, it's running about 195 now (without the heater running). In your opinion, do you guys think it will make a difference to switch this T-stat out to a 195? At this point I'll try just about anything.

Show off! Good for you and nice find.

This "Bud's" for you,



T
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Tom Greenleaf - MetroWest, Boston

I don't think it will fix your problem either way. If your not losing any coolant and it''s still overheats at highway speeds, it's probably a restricted radiator.




78 Corvette Pace Car For Sale-18k mi orig-Florida

We crossed swords for a second there.

VERIFY by VIN # if need be for correct temp. Trust me - it matters!

T
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Tom Greenleaf - MetroWest, Boston

Alright fellas, Newest update.. Drove it for the last 45-50 minutes. Temp was fluctuating between 197-225 with heat going and sitting still for 5-6 minutes(outside temp 71...Nice summer Chicago is having). Temp never went above 225. When driving about 40-50mph, temp stayed about 197-205. Maybe the flush treatment jarred something loose? Blockage worked it's way out? So I guess the question I have is, will driving the car within this temperature range be OK? Going to drive it to work tomorrow (about 32 miles), stop and go traffic.

Those temps are all normal. You haven't really tested it on a hot day though. you likely need a radiator.




78 Corvette Pace Car For Sale-18k mi orig-Florida

Hello,


When the cooling system of engine fail to absorb, transport and dissipate heat it cause overheating in engine, use high quality coolant, make sure that there is no external or internal leak in coolant,poor airflow through the radiator or defective radiator cap may also cause overheating, so check all these points properly, you may find your solution there.


Regards,
sarah_9


Please remove the advertising from your signature ASAP

(This post was edited by Hammer Time on Sep 5, 2009, 1:52 PM)