My son has a 97 Cavalier, we have had the therostat and a couple of other connections fixed. Now it seems to be leaking from the resevoir, not all the time but to often to not fix it. Any Idea what is causing this, Not sure if its the cap resevoir itself. Why would there be that much presure??
My guess is the mechanic didn't purge the cooling system of air after working on the cooling system. Take it back to the mechanic that did the work and have him fix it.
Were the repairs made because of leakages, or something else?
Dont know what engine you have in that car, but several of the V6 engines have some typical weaknesses, some of which could result in communication between the combustion chambers and the cooling system...If you have a leakage of hot exhaust gas into the water jackets, of course you may see overheating and coolant being pressured out of the reservoir.
Sorry to bring up this bit of pessimism...May be something a lot simpler and easier to resolve.
I had this exact issue on my F**d pickup truck, the problem was two connections reversed on the neck of the radiator (bypass hose for heater was switched with the overflow hose causing the system not to pressurize; it would puke when hot.)
Other possibilities include a weak radiator cap, a crack in the overflow bottle, or worst, a blown head gasket allowing the engine to push combustion gases into the cooling system.
nate
There are a few cars (VW for one) that maintain a pressurized overflow tank, but most others do not maintain any sort of pressure in the overflow tank. In fact, if you look closely, you will probably find a hole near the top of the tank to allow excess overflow to simply pour out.
If the radiator cap is bad (not holding pressure), then more coolant will push out into the overflow than should. Get the cap checked.
On some cars, an air bubble in the system can cause spectacular boiling out into the overflow. Since you've just replaced the thermostat and some "other" things, air was probably introduced into the system. Check to make sure the system was properly "burped" of air.
Other possibilities are ugly and expensive, like blown head gasket, cracked head, etc. You really want to hope its just a radiator cap or air bubble.
The '97 Cavalier uses a pressurized bottle, very similar to the VW.
Aren't most cars pressurized in the bottle now? No caps on radiators. Only on bottles. No?
quoted text -
My son has a 2000 Malibu with the 3.1 liter V6. He had this happen on a trip out west two years ago. After replacing thermostat, water pump and flushing the system, the problem was determined to be a bad recovery tank cap. The tank is pressurized during engine operation and is in fact the only place coolant can be added. The radiator itself has no cap.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.