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help needed with leaking pipe

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HI there

just had another engine fitted to my 1999 porsche 996 cab c2 (manual)as the original engine had the cracked piston liner problem. The replacement engine was running great but as I was driving home i noticed water leakimng from underneath when i filled up with petrol. The water is dripping (more like a constant stream) from somewhere up top of the engine at the back of the engine bay, on the l.h.s of the engine bay (the water is drippinng out the bottom approximately where the gearbox meets the main engine block)

It is booked in on monday to go back to the guy and he suspects one of the pipes has become lose. He said the engine doesnt need to be dropped to fix this and its a real pain to get the car over to him on monday, so i thought Id check myself. I cant see far enough towards the back to see where exactly the leak is and even if i could I am not so sure as to how you would get your hand in there to fix a pipe unless im missing something obvious to make access easier.. (like the help of a man/woman with arms similar to the stick man you drew when you were about 4)

Any help on the above would be appreciated with any actual diagrams of where all the water pipes go so i know what im looking for.

Many thanks in advance

KInd regards


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>>(the water is drippinng out the bottom approximately where the gearbox meets the main engine block)<<

Right above that area there is a line to the oil cooler which carries the coolant over to the expansion tank (drivers side UK, then the line crosses over to the passenger side).

Could be the coolant lines going to/from the AOS, at the rear of the engine (passenger side UK).

Could be the exapansion tank leaking and the coolant is travelling rearwards somehow.

Can you take some pictures for us? Even if from the under side it would help better pinpoint where it's likely coming from.

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Hi logray

Thanks for the quick response . I can't seem to get a lamp in there to brighten the areas up. Is it worth me taking out alternator to get a better field of vision etc. there are pools of water behind the alternator in the troffs on the inlet manafold top on passenger side (uk) which does point to what you say at the back , but how the heck do you get back there with your hands without dropping the engine?

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Is the coolant level in the coolant reservior (left side engine bay) low?

If coolant is pooling in the crevasses on top of the engine, the coolant could be leaking from the oil cooler, oil cooler line, tiptronic coolant lines, or the AOS coolant lines. They are all on top of the engine and would explain why coolant is pooling on top of your engine.

To get at these areas at the rear of the engine without removing the engine you have to remove the intake from the top, and in some cases the alternator and/or air conditioning compressor. Search for DIYs on AOS and oil cooler for more details.

Still, before diving into any of that I would try to get a better sense of generally where the coolant is leaking from. With a good flash light or light and the car on stands (or even on the ground) you should be able to better pinpoint where the coolant is flowing from. Do wear protective googles as coolant is extremely toxic and could cause blindness. You could run the engine very very briefly to see where it might be flowing from. But do not run the engine long enough to get it up to temperature or create a hazardous material cleanup situation, poison or injure yourself, or anyone near you. Do not run the engine any longer than required to diagnose the leak. Do not operate the vehicle until you can resolve the leak, as low coolant level spells disaster, overheating, and serious permanent engine damage (not to mention bad for the environment).

To get a little bit more room from the top, you can safely lower the engine down on the engine mounts until you can no longer see the threads (loosen the mount nuts until the threads at the bottom of the mount studs are hidden by the nut). If you do this, always support the engine safely and correctly from underneath to prevent a big mistake.

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Many thanks for Logray and fpb111. I took advice from you both! found the leak by going underneath and shining a torch up whilst wearing glasses, spotted it was one of the smaller pipes going to the aos, it had a small hole close to the end of the pipe where the clip sits. Read up on in the diy tutorials on how to get to the IOS and decided to ring the bloke who fitted the engine and convinced him to do it tomorrow and ill go watch so i know for next time, at least he knows whats wrong immediately!

I really appreciate and respect the level of knowedge of the members and the people who run this site. I have the taste for champagne and the money for wine and only manage to continue to enjoy this car by keeping the costs low by the invaluable help and advice.

Many thanks again



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