pls tell me its not a cracked head

[mickeymousin]

Ok- I have read the "sticky" and will be as specific as I can. Not sure about engine type. I can tell you it is a 95 grand am gt. hope that is enough....


I have had heater core replaced twice in 2 years.
Had the thermostate replaced approx 4-6 mos ago. At that time, car was overheating and when temp would rise cold air would blow out when heater was on. Then temp would go down and heat would blow out again.

Now-the same thing has happened a few times but then again-there hasnt been a need for the heater everytime I drive. Also, the temp gage will sometimes go bezerk! heating up and then instantly go all the way down or down to normal and them almost always shoot back up. Car doesnt seem to heat up on reg roads-just hwy and it seems at speeds over 65 (which I for some reason cant seem to drive below that ) Water has to be put in quite often.

Well took it to shop. Husband called them and was on phone with them and they said they put a pressure tester (?) on it and the next morn checked it and no pressure lost. then said that after starting it, water was leaking out tailpipe. At that point, H said he had to go and hung up on them! He is a DJ at a bar so he only had 3 min to talk.

Anyway-that is where I am at. Any ideas what Mech was getting to based on that?

[GTP Dad]

Is there any way you can find out if this is a 4 cylinder or a V6? If it is a 4 cylinder I would believe the problem is in the water pump not the head. If you don't overheat while sitting in traffic and only on the highway that indicates to me that the water pump is not working well enough to keep the water circulating. If it is a V6 then the waterpump could be your culpret too but I would suspect that there may be a problem with the intake manifold gasket. The Gasket can break down and cause water to enter the combustion chamber just like a cracked head. Have you seen any foam or evidence of water in the oil? Sometimes when an intake manifold gasket goes it will put water into the oil causing problems. As far as water coming from the exhaust, ask them if the water is clear or is it green or red. If it is clear then that is a natural part of the combustion process where the catalytic converter changes the exhaust gases to CO2 and water. If you don't smell antifreeze and there isn't a cloud of white smoke, I would look at the intake manifold gasket first as well as the water pump. You may also want to change the temperature sensors as there may be something wrong with them causing false temp. readings. I would also have another thermostat put in the car and check all hoses to insure they have not gone bad. The current hoses will go bad internally without showing problems on the outside and can cause you problems. As far as you question concerning a cracked head, I can't tell you for sure it isn't but if the garage did a pressure test then it should be OK, although it could be cracked and only showing up once the head is warm. Ask them to pressure test it with the car warmed up to operating temperature that should tell them for sure. Hope this gives you somewhere to start.