coolant leak
 

Hey everyone
I came out of the store to find a trail of coolant leading to my car, and a puddle in front of my passenger side rear tire, rats. drove it home, same thing puddle by tire. I've inspected the tank, no coolant in trunk, carpet dry. The hose connections on the engine side, all dry. Coolant is all over the lower wishbone and the inside of the wheel. The only sign of moisture is at the tip of what I suppose to be some kind of a coolant overflow hose which is clipped to the brake line. It's a 2000s, All was well with the coolant level two days before, car runs at about 180. Help, please.

Did you check the coolant tank itself? It's a notoriously terrible design and they often crack. If that's the case, take a look at the link below for the DIY replacement procedure.

https://www.pelicanparts.com/techarticles/Boxster_Tech/33-WATER-Coolant_Tank/33-WATER-Coolant_Tank.htm

Thanks Dmitry
I don't see any evidence of a tank leak. the trunk is dry, i took up the carpet. Should I pressurize the system to be sure?

Same thing had happened to me... after some spirited driving. It burped. I had the same trail of coolant.

Added distilled water to bring it to level... opened the vent to allow the system air to escape (for a few days). Paid attention to the level... hasn't happened since.

IMHO... if you found no wet in the trunk... leave the coolant tank alone.

Likely just a one-off. Surely a real pro will chime in.

The relief valve that you use to burp the system can sometimes get tired. There are o-rings under it that might be worn and I had one that actually split in half at the track with the coolant pouring out of the overflow hose causing a spin! End of my event, obviously.

I just went through this very same issue. A shop had recently replaced the relief valve on the tank and neglected to remove the original o-ring. So I had two o-rings in place and both were mangled due to them trying to tighten everything down.

Pelican hooked me up with o-ring dimensions (47x4) and Pep Boys hooked me up with free o-rings. 5 minute job to replace it, but be careful tightening down those screws into the plastic housing.

Got the low coolant level light for a few days even after topping off, but I had lost nearly a gallon of coolant and figured I had air in the system.

Could also be the tank cap. It happened to me. Replaced the cap and the problem is now solved.

If the part number on the blue cap end with a "-01" then this is your number one suspect. It must end with the revised part number: "-04"

I also agree with cap, check what version you have....besides, it's the easiest thing to check (and most likely the issue).

thanks for the great response! I can't wait to try your suggestions. You guys are amazing.

If inside carpet is dry probably the cap. I had some overflow last year cause the service was done in oct. Fluide was on max, so when hot weather hit 42c had some overflow, stopped after it dropped a bit below max.loose or cross threaded cap will cause it to over flow some also.

I'll chime in with probably the cap, especially if the part number on the cap doesn't end in -04. If it doesn't, change it anyway. It's cheap (under $15). If you get it at a local Porsche dealer remember to ask for your PCA discount. :) Also be careful when installing the cap. The same thing can happen if the cap isn't screwed back on quite right.

Thanks, NA. Hadn't considered that valve/o-rings as a wear item. Nice to know.

I did fail to reveal that I replaced the cap with the current part.

Man, I love this forum.

I'm in agreement with the other forum members on replacing the coolant cap. It's a cheap step to avoiding coolant loss.

I had a similar coolant dump that was caused by a crimped o-ring in the pressure relief valve. I sourced a replacement locally for $5. As others have noted- it is a 5 minute job to take the valve apart to inspect the O-rings- there are two. Just be careful not to strip the screws when you re-assemble it.

Yeah, another nod for a cap... or there was an air bubble trapped somewhere that finally found its way out. My $$ is on the cap.

I had exact similar issue. I took out carpet - no coolant. Borrowed pressure testing kit from autozone, no pressure drop or leak. Changed the cap to .4 I had .1 . Added Porsche coolant (that's what car had), burped the system and leak is gone for good. Pistonhead has a step by step instruction on how to burp the system.

coolant cap and o rings on the way, thanks again everyone.

problem solved! new cap did the trick, thanks again to the boxster bros!

I also had similar problem solved w/updated cap 2004 S. Installed new water pump (twice)yesterday. 1st time I had folded up the gasket but knowing I'm a clutz I had ordered an extra. Flushed coolant system and installed new Tstat and housing. One new radiator hose and have a new motor mount but was not strong enough to break any of the bolts loose? Anyone else installing water pump for the first time should watch youtube video by Ben Burner for his "FRANKENWRENCH" works great for that one bolt you cant reach!!

I seem to have a similar problem. Carpet in trunk is normal, when I pull it up including the foam type insulation it is sticky on the metal under the foam. I presume that this is coolant?