Topic: Blown Head Gasket?

[98Black5.0]

Ok here is the problem. my 96 gt is overheating but only when im driving it. If it is just idleing then its straight. my fan light comes on and then it will go off. but it wont stay on while the coolant temperature sensor is plugged in so i keep it unplugged. I took it to a shop for someone to look at it and he plugged the sensor back up and it started to kick on like its suppossed to. he looked at it and said the motor seems to be fine then he kept squeezing the radiator hose and it had a lot of pressure and said that itis prolly a head gasket problem. Can someone give me their opinion on this problem? I also have the heater core bypassed.

[Soaring]

If it were a head gasket blown, then you would see white smoke coming out the tail pipe and most likely water in your oil, and oil in your radiator.  Take your thermostat out and  drill a small hole in it, then put it back in and see what you get. 

[98Black5.0]

There is a little white smoke but its hard to tell cause its cold. Condensation coming out the tail pipe and he looked at all that checked the oil and there is no water and nothing mixed in with the antifreeze but he still said its a head gasket issue cause of the pressure building up. and you can feel it in the radiator hose.  I mean what else could it be?

[Soaring]

A little white smoke at startup at this time of the year could just be condensation burning off.  If either the intake manifold  gasket or the head gasket is blown, you will experience a distinctive miss from those cylinders.  If, after driving for a few miles, and you punch it, you will get a lot of white smoke out the tailpipe if the gaskets are blown.  The pressure build-up on the hoses is quite normal, but something you may want to pursue.  You may have some blockage in the system.  Take a compression test on each cylinder to see if one or two cylinders are below normal from the rest of them.  If it is, then you could possibly have a blown gasket.

[98Black5.0]

ok well i havent noticed any white smoke come out while im driving or while i get on it but i do hear a weird sound while i get on it around 3000-4000 rpms but only sometimes. there are no physical signs of a blown head gasket to me but it could be. i have noticed that a couple times when i start it and give it a little gas it stumbles a little bit from idle - 2500 rpms. it might be a  dirty fuel filter or something but it goes away as soon as i rev it up and doesnt ever do it again while the car is started.

[Soaring]

That's the typical reaction from a blown intake manifold. 

[98Black5.0]

well the intake manifold on it is new from what the mechanic said and from what i see. its black and real clean. do you mean intake manifold gasket? how could i tell if it is blown

[Soaring]

OK, I guess I misunderstood.  Now, you say it is black smoke and real clean.  I don't understand how it can be black and clean.     If the smoke is black, then it has to do with worn rings, and blow by.  The cylinders are burning oil if it is black, or you are running a very rich mixture of gas through your carb.  If the intake gasket is blown, you will get white smoke on startup, then after the engine gets warmed up, 'you can rev the engine and blow the water out of the cylinder, therefore getting a big puff of white smoke from the tailpipe.  If the smoke is constant, and is black then that is not your problem.  You need an engine overhaul if the smoke is constant black. 

[ol dirty doug]

i think he is talking about the black plastic intake manifold, it being black and clean.

[Soaring]

i think he is talking about the black plastic intake manifold, it being black and clean.

Oh, OK.  I thought he was talking about what was coming out the exhaust. 

[rmodel65]

go to autozone and rent the coolant system pressure tester...pressurize the coolant system and see if the pressure maintains of drops....



how does your oil look? does it look like a milkshake? if so its a blown gasket.....does it look like theres oil in the radiator fluid??

[98Black5.0]

The oil is fine. Also something that concerns me is that when i changed the thermostat that there was some krums of something in there. its hard almost like jb weld. About a dime size but was all broke up.

[Soaring]

Change out the rad fluid again, and replace that thermostat with a new 180.