Hello,

I have a friend that has just purchased a Porsche 944 5-speed (non-turbo) about two weeks ago!! We have just replaced the overflow cap and the thermostat!!! Now we have major overheating problems!! The car when being driven, the tempature guage is passing the yellow mark!!! Then when we turn the car off the overflow is sucking in air so it looks like it is boiling and it is leaking out of the overflow hose!!! We have bought a new thermostat which is 180 F and and new overflow cap at 13lbs!!! If anyone has any suggestions I would greatly appreciate it!!! Also if someone can list some good sites to get parts or good pages about 944's would be great help!!

Thanks,

Shawn

 

did you bleed the cooling system? maybe theres air in it?

 

Yes I bled it!!! It worked fine going home and then on the way back it started up again!!

Thanks,

Shawn

 

Is the passenger footwell wet?

Could have a leak and the least noticeable is the heater core, which has a tendency to leak into the footwell.

 

No,

It is dry!!

Thanks

Shawn

 

Bleed the system after you have driven it a little. Also, a VERY common cause of overheating is the fan switch. That is what was wrong with mine and quite a few other peoples. Let the car sit and idle and see when the fan cuts on, and then of course bleed it yet again.

 

You're new to the board, are you aware that these cars have very specific bleed technique? Just wondering.

 

How excalty are you suppose to bleed it?? What I was doing was filling the reseviour and taking the cap off the top of the hose and letting the water come out and then filling it agian!! It worked enough for the night!!

Shawn

 

Nope, that won't do it. Do a search for the correct bleeding technique, there are several recent posts on this topic.

The bleed screw is on top of the engine beside the fuel rail.

You have to keep doing it until no more bubbles come out, just coolant.

 

Whoa, that's a lot of exclamation marks.

 

Best to put the front of the car a foot or so higher than the back. Putting the back wheels in the gutter of a drive way enterance usually does it.

Open the heater valve to let coolent circulate in it and keep the bleeder open as the car heats up. Really have to remove all of the air before you close the bleeder. Don't break off the bolt!

As mentioned above the temp switch on the radiator and the relay for the cooling fans on the radiator can cause porblems if they don't work correctly.

What year is the car?

 

I had a similar problem recently -- overheating with excessive pressure at the reservoir cap. I thought I just didn't bleed the system correctly, but the problem didn't go away no matter how I bled the system. On top of it all, I was also losing coolant, slowly but surely...

My problem turned out to be a blown head gasket (hence the coolant loss and excessive pressure). Unfortunately, I didn't figure it out until I started getting white smoke out the exhaust -- by that time, I had already scorched a cylinder

I don't know how you can tell that you're having the problem, but don't keep driving the car until you figure out what's going on!

 

Yup, I think Joe has your answer. Luckily, changing the head gasket is definitely in the realm of feasibility for a moderately well-equipped home mechanic, and is also a great excuse to take the head to a machine shop for milling, new guides, seals, and lapping. If corrosion is the root problem, some welding may have to take place. GL!

 

shawn,

Don't freak out, it could be your head gasket, but that isn't the end of the world. Well, the end of your friends world anyway.

The bleed screw is on top of the engine where the coolant line runs into the engine. It is a little 12mm bolt that points straight down. It is really easy to see. Just get the car warmed up a bit and loosen that bolt and wait for coolant to come spewing out. Then wait a few more seconds. Fill the resevoir back to the line and drive the car for a few minutes and try to bleed it again. I have never had any problems getting the air out of the line. I don't know, maybe it is just certain cars that have problems.

Try that and if that doesn't work just let us know and we'll get an opinion about what else it might be.

 

www.paragon-products.com has alot of stuff you could use.