Ted Rodgers

I have a 2004 CTT with coolant leaking from the breather holes in bottom of the torque converter housing. The only thing I see in any engine rendering is two "freeze" plugs (lids 94810121600) as possible causes or a cracked block. If this assumption is correct I also assume the only repair is removal of the transmission and torque converter. Or is there another possible cause?

Has anyone had a similar problem and what was your ultimate cause and repair. Any help or input would be appreciated.

Thanks in advance.
Ted

PS: I also listed this in the Cayenne DIY forum.

C4SJOHN

This may be you problem, Coolant line tee assembly for turbo Cayenne only. This is common issue.

Coolant Vent Line "T" Fitting Reference Porsche Part Number: 955.106.323.50. Here is a picture of a bad one. https://rennlist.com/forums/attachme...-z-crusty2.jpg

bigbuzuki

Most common cause for this defect is:
1. As C4 has mentioned it could be the plastic t pieces.
OR
2. Do you still have the plastic coolant pipes?

If either the t pieces or pipes are cracked, they will be losing coolant which drains through to the transmission housing.

Quite common for your vintage Cayenne.

The coolant reservoir cracks as well, but the coolant does not drain through the tranny housing.

s4for5

T connection or coolant pipes, and yes, even newer metal ones can leak it should be addressed asap.
The Transmission seal does not take kindly to having coolant washing over it which means pulling the trans out for sure if that starts leaking.

Ted Rodgers

I checked for the aluminum coolant pipes before I purchased. They had been replaced. However 2 weeks later the plastic "T" I think you all are referring to failed from a factory clamp being clamped too tight. When that happened all of the coolant drained over the rear of the engine and over the outside of the trans case. This time no coolant is on the outside of the engine or trans case. It only runs out of the breather holes. I have been removing as much as I can hoping to get a better look at the "T" but I see no way for it to drain through the torque converter housing instead of over it. If there is an opening on top of it I would appreciate any suggestion as to where to look for it. Any other ideas, I hope there will be more, will be greatly appreciated.
Thanks
Ted

s4for5

I'm still suspecting a leak in the coolant pipe area.
There are still hose clamps used with the metal pipes.
Mine mysteriously loosened a bit which cause minor weeping.
Found it during starter motor replacement.

Orantes

The thin 'h' tube which runs over the top of the coolant pipes under the inlet manifold can also fracture. It gets very brittle. Drips will start small and end up emptying your system when the full fracture occurs.
Basically, any leak beneath the inlet manifold will trickle / flow down the back of the engine and out the small holes at the bottom of the transmission bell housing. Good luck.

Orantes

The part denoted 21...

nguyenaq

I just tore my car down again for the 2nd time to repair a coolant leak (the 1st to replace the Ts--already had metal pipes done by dealer years ago). The big coolant pipe that runs underneath the 3 smaller ones had it's worm clamps loosened, which sprung a leak right by the black coupler. I'm changing out with new worm clamps and will be using loctite to make sure they don't backout over time.

deilenberger

Tony - isn't that (21) the vacuum line that cracks when it's touched to replace the coolant pipes? I think the T is #5.. maybe.

Orantes

I am not actually referring to the 'T', I am instead offering up another possible source of coolant egress. The 'h' (21) pipe is referred to as a 'vent line' and is usually replaced as part of the coolant pipe kit. Many people don't realize that coolant actually has the potential to exit via this vent pipe if it is fractured. Trust me, I know this from experience!

Ted Rodgers

Thank you all for your input. I have attach 3 images of the rear of the engine, the front of the transmission, and a close up of the 2 freeze plugs in the rear of each cylinder bank. The rear picture shows the web of coolant hoses every commenter believes is the source of my problems. Unfortunately I fail to see how any of them leaking would send all coolant through the bell housing and out the vent holes at the bottom. I find no vents or other opening at the top to allow entry for the liquid. A slow seepage could make it through the joint between the engine and trans mission but that tight joint could not flow a gallon in 5 to ten minutes. The only way I can see that volume flowing is for it to flow over the top of the bell housing and rear of the engine. Therefore I am forced to believe it is one or both of those freeze plugs. Please prove me wrong. Thanks again for your input.
Ted

v10rick

Countless transmission seal failures have been reported caused by coolant leaking from the valley under the intake manifold. The path is the area where the starter drive enters the bell housing.

I don't have personal experience with the CTT or the location of the T that fails but if it can leak into the valley under the intake it will find a path into the bell housing.

If the T is not the culprit, a different line is leaking .

http://www.callasrennsport.com/wp-co...lant-Pipes.pdf

Ted Rodgers

Thanks V10Rick. I think you answered my question. The drain holes under the starter are not mentioned in any of the literature I have read yet nor visible in the pictures or manuals I have. That also explains the delay from when I pour coolant in to when it starts leaking out the bottom of the bell housing. Now for the dirty work.
Thanks again.
Ted

v10rick

Good luck Ted and please report back with your findings.
Clear shots of the leak, like the engine shot above, would be a plus.