Just a question for any of you guys who have had the coolant expansion tank leak. Did it leak only after the car had been driven, or did it leak while parked in the garage? My car leaks directly below the coolant tank but only after I drive it which makes me think it would be a ripped hose. I figured if the coolant tank was cracked it would leak even while standing there without being driven.

 

CHeck your coolant cap. If it is blue, it is the old cap and should be updated to the black cap. The blue caps tend to leak and coolant will drip into the overflow drain hose and down onto the exhaust.

 

Coolant expansion reservoir plastic should be white . When the tank get older the color goes towards a brownish color. That mean the plastic is getting brittle. Of course when the engine is warm there is is pressure inside that tank and if a crack is starting on one of the seams it is a possibility that it will only leak under pressure... The best way is to pressurized the coolant tank at the cap and do a good leak check before spending money on a tank... There is a DIY on 6speed for the coolant reservoir https://www.6speedonline.com/forums/...ank-996tt.html. Take a look at the plastic before and after.... The Porsche doc got also a very good point about the cap....

 

Just checked the cap its blue, so hopefully switching to black solves the problem. The coolant does spill onto the exhaust tip so it seems likely. Thanks for the tip.

 

Thanks for the DIY, I read through it and started to hope that the tank wasnt leaking because it looks like it would take me a few hours to change. The only reason I believe it isnt the coolant tank leaking is that my tank looks pretty new (still white), and the car only has 27k miles on it. I might get lucky just replacing the cap so we ll see.

 

You can also drive the car, pull that small overflow rubber hose up into the engine bay and then watch it when you turn the car off to see if there is fluid coming out of the hose, etc.

 

turns out its not the cap, I checked the hose it was dry after a drive, I put paper towels around the cap and they were dry too. However, its not the coolant tank either because I looked under the car and I see a few drops by the passenger header and a puddle in the back on the side of the cat. It makes me think it is a ripped hose or perhaps it has come loose, does anyone know if there is a hose that runs from the coolant tank toward the passenger header?

 

exactly where mine was dripping to...exhuast tip. you figure when its on and coolant is hot it expands and thats largely what the tank is for. plus its under pressure like already stated. if the level of the fluid is above where the hole is it will leak. if its not, it wont. its almost impossible to see where the thing is leaking without the tank out. and thats why i did my little science project below. thats on my old totaled C2 tho and from looks of it easy to get and in compared to the turbo. still not a project i would pay anyone to do tho. just lower the motor a bit and knock it out!!

https://www.6speedonline.com/forums/...on-tank-2.html

 

I really hope it ends up being just the coolant tank, it seems everything else would require more work to take apart the only reason I m worried now is the dripping on the driveway I saw by the passenger side header, but it could just be coolant running along the hose and dripping over there rather than a leak there.

 

Wait a sec! Its dripping onto the passenger side header?? I would put that in the very unlikely to be coolant tank camp.

 

[CODE]lifted the car up on a jack and got under it, turns out by the passenger header was a oil drip which I think is from the drain bolt. So that means it might just be the coolant tank after all, I guess my next step is to rip out the coolant tank and inspect it for leaks.

 

Its a lot easier to get out than to get in. If ur coolant leak is on passenger side i really doubt its coolant tank. If leak is on driver side its much more likely to be tank. Make sure u local porsche dealer has one in stock or u already have replacement. Id say if u gonna pull it, no way in hell i wouldnt just replace it.

 

the passenger side leak turned out to be a small oil drip from the drain plug so I tightened it up a bit and now its fine. You are right about the coolant tank, if I spend all that time taking the coolant tank out I might as well put in a new one, I guess I ll order one now so it will be here by the time I decide to tackle that job.

 

I see I'm a little late to the party (since you already removed the tank) but I experienced the same thing as you and it turned out to be one of the clips...
Those damn clips (at connections) are notorious for leaking!
Weather it's because the rubber-hose dries out over time or the clip gets play in it, the end result is the same... leaks.

Would have cost me hours of labor to take it of flush the system put new coolant etc. so I just added a standard hose clamp in front of it and no more leak.

Got a hose replacement by the dealer and the brand new clip (front radiator) came off!!! got stuck on the side of the highway with coolant all over my car
After dealing with the nightmare of getting a lowered P. on the 4th flatbed.... I decided to put extra hose clamps on ALL my connections...

A sh#t load of clips... $12,-
Peace of mind... PRICELESS

Cheers,

Sid.