Hi everyone! This is my first post on Rennlist though I'm quite active on Pelican.

First off, my car: 2007 997TT with 97K Kms; I got this sweet car on a trade with my 2006 C4S back in June 2014.

The problem: As I was about to store the car for winter late last November, I noticed a small puddle of coolant under the RIGHT (not left) side of the engine. I hadn't driven the car for about two weeks at that time. I checked the coolant level to find it at just above the min level.

FFW to last week: I took the car out of storage and checked the coolant level. It was still just above the min level. I added distilled water to just below the max level and ran the engine for about 1/2 hr (fully warmed up). I then let the car sit for three days....no leak. I then performed a coolant pressure test with a Stant tester and appropriate adapter...20+ minutes @ 16psi...no leaks...pressure held steady! I then drove the car (not aggressively mind you!) for about 2 hrs. I parked the car in the garage and then I just let her sit. I kept checking for the leak about every 4-6 hrs...nothing. And then this morning, after it sat for 2.5 days....the puddle is back!

After doing some research here on previous posts, my first thought was to replace the (blue) expansion coolant tank cap. What say you gentlemen (and ladies?)?

Cheers!

Alex

 

if you notice white residue on the exansion tank its from a leaking tank cap.

replace it for around $35

 

As you point out, it's odd that it would be the right side that's leaking if it's the cap. The reservoir and the water pump are both on the left.

The cap is a cheap try, but i wouldn't hold out a ton of hope with that. My engine is out, I'll look around to see what connections could be the culprit.

 

CincyScott, yes it is odd that it's the left side...that's why I highlighted that fact!

I would greatly appreciate your input here as you mentioned that you've currently got your engine out....yes, please have a look around and see what you think!

Alex

 

^^^Sorry! I meant RIGHT side!

 

mmm... It cannot be the coolant fittings this early on a street car?

If it were the fittings you think you would see the white smoke when driving...

 

I hate to say it but that's exactly how my coolant leak started. At first I thought it was just AC condensation because it was so infrequent and on the right side, but eventually it became more frequent. The right side was just because the fluid was wicking that direction from where it was coming out. If you search you'll find pics of my car when this happened. This happened on my car when it had 34k miles and was before I ever really took it to the track.

 

Could be a coolant fitting starting to let go. These are glued into the block and it was determined that Porsche switched this glue on the 997 Turbo and GT3's. Many have fittings let go and the car doesn't have to be tracked to have the problem. It's just a matter of time and luck before they do let go.

 

oops! double post!

 

Unfortunately this might be the answer. I believe mine was also leaking on the right well away from the coolant tank. I think you're gonna have to drop the engine to be sure.

Maybe it's the water pump? I don't remember which side of the engine that's on. If so that's a cheaper fix.

 

Water pump is on the left.

 

So I went to visit my car today, and here's some pics of the right side of the engine (Passenger):



The main component missing from this pic above is the intake on the right side. The gaping connection open is the feed line for the radiators, comes in the left side, goes out the right. If that one was leaking, I'm sure you'd know it.

Below is the line on the right side of the oil sump (this is one of the 3 that you replace with the sharkwerks kit that are plastic from oem). It's underneath the intake, and will very hard to spot.



This last one is the fitting where the above connects to the main cooling body in the rearmost section. This is one of the fittings that gets pinned or welded when they come out:



So the fitting under the oil sump on the right side follows along under the intake with a rubber hose and connects to this fitting in the rear of the engine. You MAY be able to see this one with the engine in. I tried to highlight it with a screwdriver.

Hope this helps!

 

I'm still getting the occasional small puddle of coolant on the floor underneath my car on the left side. I just had the system pressure tested by my local Porsche dealer and it checked out just fine. I may try a new cap...

 

Scott thanks for your time in taking and uploading those pics!

I suspect it's probably that last fitting you've got the screwdriver on. Here's a pic showing the actual leak:




You can see the trail of coolant to the left! So what lies directly above this area...is it that last fitting you showed us?

Alex

 

You're most welcome. I would suspect it's the fitting under the sump at this point, but you never know with water always finding the lowest point. I think we know now that you can save the $35 bux for the cap

I think you can lower the engine on the mounts and possibly gain access to the affected area. Good luck and keep us posted!