Coolant System

[jkubiak14]

Looks like I over tightened the cap on the coolant tank. The plastic threads appear to be stripped and it will not tighten very much. I did find a position where the cap feels kind of tight but if I turn much past that it goes to loose again. Can this be fixed without replacing the entire coolant tank? I was thinking of maybe some kind of silicone sealant on the threads might help. The system seems to be OK for now after a brief test drive, but I am worried about losing pressure if the cap is too loose. Anyone else have this problem? Thanks for any advice.

[dadio]

Given the fact that the cap is supposed to go on with a good bit of force I'm a more than little surprised you were able to strip the treads of the tank. Have you tried a new cap ? If it's the treads on the tank you destroyed silicone isn't answer. You'll need to replace the tank and the cap at the same time.

[jkubiak14]

Thank you for the response dadio. I am puzzled and surprised as well. I originally took off the cap about a month ago to take a look at the fluid color and get a better look at the coolant level. It was difficult to remove by hand. Seemed ok so I tightened it up by hand. Later I drove to work about 20 miles and when I shut off the engine, steam arose from the rear engine compartment and I saw about a gallon of collant on the parking lot pavement. I was able to get some antifreeze and put almost a gallon in the tank and tightened the cap by hand even harder. I made the trip home ok, but the next day I was worried that the cap wasn't on tight enough. Like a dummy, I applied a wrench to the cap and got it really tight. Everything was fine for a month, but I was still worried and tried to remove the cap to check the fluid again. It was so tight I needed a wrench to loosen it. Upon putting the cap back on I discovered that it wouldn't tighten very much and that when running the engine, fluid leaked out and ran to my garage floor. I played with the cap, finding the tightest position possible and test ran the engine. It seemed ok. I just made it back from work, about a 40 mile round trip with no problems. Temp guage needle just a little right of vertical splitting the 8 and 0. The sysyem appears to be sealed, but I am nervous about the cap being on too loose. Any ideas besides don't fix it if it ain't broke? Thank you.

[Aerkuld]

Have to agree with dadio on this I'm afraid. Look at it this way;

A new header tank is a hell of a lot cheaper than the problems you are likely to encounter with an overheated engine.

Another possible problem - what antifreeze did you use? If you use the wrong stuff you might run into more problems. The Porsche antifreeze can turn into jello if you mix it with an incompatible type.

I don't want to scare you, but I'd hate to see this turn into a catalogue of disasters.

[eric523]

If you used prestone or the like then you should flush out the system and use the proper Porsche coolant for your car. In the event you need to top off and don't have any available, just use water.

I have never heard of somebody overtightening the cap, but if you cranked on it with a wrench and stripped the threads then yes, you should replace the tank. Using silicone or band-aiding it will just cause more problems in the future. Save yourself the hassle later and replace the tank properly.

Overheating these cars is a big no-no as with any. If it does start overheating, turn it off, don't "try" to make it home or around the corner etc. Seen too many failures due to cracked heads etc.

[jwetering]

Tanks are cheap - about $200 and replacement can be done DIY. The cap is on it's 4th version or something by now also. Replace that too.

There's lot's of threads on coolant tank replacements, if not here then at Rennlist. There's a procedure written on Renntech I think, or 6-speed online...maybe it's at Rennlist. Sorry, I can't remember exactly where it is, but it's not hard to find once you start looking.

I've done two now, both in the 3.6 litre cars, and they are harder to do.