GT3 coolant leak (997)...

[braddo]

My 997.1 GT3 sprang a leak during a drive this morning. Am waiting to get recovered to the nearest OPC.

It hasn't lost loads of coolant and the leak can't be pinpointed - somewhere near the back of the header tank and behind the inlet manifold. Does anyone know of a particular weak spot back there and how much time might be involved in fixing it?

[Trev450]

The header tanks are prone to splitting so may be that.

[braddo]

The header tank is dry on the outside (other than a bit of residue from the coolant spraying around from the leak) and is holding fluid. The leaking stops when the car is turned off and after an hour of waiting for the AA, the leaking didn't recommence until the coolant got to normal operating temperature.

With the engine idling and coolant leaking on the ground, it was not possible to see the source of the leak. It appears to be somewhere above the engine and hidden behind the inlet manifold. There was quite a bit of steam when I first stopped as a result of coolant landing on the engine/exhaust.

It has only lost a couple of litres and there was no overheating. Thankfully I got a message from the car to 'check coolant' and was able to pull over in a safe spot in a village. Mr AA couldn't see the source of the leak so the car had to be recovered, to the nearest OPC, Guildford.

Are there other particular spots where these leaks are known to occur?

[hornbaek]

The coolant hose is known to leak. Its an easy repair.

[braddo]

Update:
The leak is coming from somewhere near the bulkhead that cannot be seen. Stuff like the inlet manifold and alternator is going to start coming off until they can see the source. If that is unsuccessful, the next step is dropping the engine...

[braddo]

Further update:

A flange where the coolant goes into the engine has ruptured. Due to it being back near the bulkhead, replacing the part is not possible with the engine in situ.

I can understand coolant hoses and header tanks perishing over time, but has anyone heard this sort of failure before?

[Cunno]

braddo said:

Further update:

A flange where the coolant goes into the engine has ruptured. Due to it being back near the bulkhead, replacing the part is not possible with the engine in situ.

I can understand coolant hoses and header tanks perishing over time, but has anyone heard this sort of failure before?

If your talking about we're the pipes fit into the engine block then yes this is a well known issue. 7 point in total on a GT3 engine where the fixing is glued in, and over time this can fail and dump coolant all over the rear wheels very quickly. Has been know to cause accidents. Many a thread on Rennlist discussing this and how to fix.

http://rennlist.com/forums/997-gt2-gt3-forum/67927...

http://sharkwerks.com/porsche/technical-articles/3...

[braddo]

Cunno said:

If your talking about we're the pipes fit into the engine block then yes this is a well known issue. 7 point in total on a GT3 engine where the fixing is glued in, and over time this can fail and dump coolant all over the rear wheels very quickly. Has been know to cause accidents. Many a thread on Rennlist discussing this and how to fix.

http://rennlist.com/forums/997-gt2-gt3-forum/67927...

http://sharkwerks.com/porsche/technical-articles/3...

Thanks for posting, it sounds like this is the culprit. From the rennlist thread, it appears that there are two of these pipes around the back in the one casting, so if that whole piece is replaced, at least the other potential weak spots are in more accessible areas and presumably, will not require engine removal if they ever leak/rupture.

[tonygt3]

braddo.
I have recently taken ownership of a Mk1 GT3.
The previous owner, whilst the engine was out for other work he had these damn water pipes welded in place.

give this some thought if your mota is a long term project