ltooz_a6_a8_q7

Hello all,
If you have coolant leaking from behind the alternator, it's the oil cooler plastic coolant pipe and only when the car has been turned of and the engine is hot (the pressure is high), the leaks will get worse as time goes by. If you want to be sure that it's not from the water pump, remove the driver side timing belt cover and run the engine to see if the coolant squirting out from the water pump. You may have to remove the fan and if you do make sure the wires are disconnected before running the engine.
http://www.youtube.com/watch?v=ufoXNwD75MQ
http://www.youtube.com/watch?v=EGzAfTEqF1I
http://www.youtube.com/watch?v=4JYj6m6f_ms
http://www.youtube.com/watch?v=ufAmHqgVHbE
http://www.youtube.com/watch?v=dv1TMj-U684
http://www.youtube.com/watch?v=X0zDZkFwN4o

In my case, I replaced the water pump by mistake without checking the engine running and the oil cooler. The leaks are from broken $12 plastic coolant pipe.

Make sure to check the new thermostat working before replacing the old one, once in a while, the new one doesn't even work. Put both of the old and new one in hot water to see if they both open and close "all the way" at the same time or off a little.

How to remove the oil cooler out to replace the plastic coolant pipe is here in the end

http://www.dognmonkey.com/audi/a8-d2...placement.html
http://www.dognmonkey.com/audi/a8-d2...placement.html


Cheers,

Louis

Blue44

Absolutely F'n cool! I do not own an A8 but I love the post. Thanks for the detail / and Video!!!

mk4jetta

Have the same issue with our 01 A8, ill have to check this out.

thanks for the info

ltooz_a6_a8_q7

Check the leaks and if it's the oil cooler, then you can go here for reference

http://www.dognmonkey.com/audi/a8-d2...placement.html

Cheers and good luck,


Louis

Kneale Brownson

There's a guy in Texas who made aluminum replacements for the plastic junk, and put two O-rings on each end for seals.

https://www.audiworld.com/forums/sho...t=James+Bufkin


By the way, is there any means for getting a copy of your repair videos? Is there a way to sneak them off UToob?

ltooz_a6_a8_q7

I read about the aluminum also, but I don't know where to get them. But I think if the car is not over heating and the oil is adequate, the plastic pipe and o-rings should last a long time. In my case it's 155k miles. I think it's OK to replace them after another 100k miles... :-)

The videos I have is in HD 1280x720, it's a little big. If you find a website which I can upload, I'll upload them for you.

Cheers,

Louis

Kneale Brownson

He was making them and mailing them to listers who wanted for $25 shipped with four O-rings. I have one in my spares for the next S8 TB job.

I don't know of a website you could put the videos on so others could download them. Maybe someone else will jump in. Thanks.

ltooz_a6_a8_q7

You can download youtube video using these

http://www.youtube.com/watch?v=kROemCVsWA0

http://www.downloadyoutubevideos.com...&GetVideo.y=30


mp4
http://googlesystem.blogspot.com/200...mp4-files.html

ltooz_a6_a8_q7

About the aluminum pipe. I'm sure Audi Engineer would have thought of using metal pipe, but I think they prefer to use the plastic pipe because they want to make sure people/mechanics don't accidentally misalign the pipe and scrape the inside of the block, then the block is gone. I wouldn't even recommend using the aluminum block.
The reason when we removed the oil cooler, the pipe always broke because the old O-ring stuck to the block and the force on the oil cooler is too strong, when we pulled it out, the pipe broke off. The leak is from the dried harden O-ring, NOT the broken plastic pipe.
If someone made higher temp O-ring, buy those instead of the aluminum ones. Just imagine if you scratched the inside of the block, the O-ring will never stop the coolant from coming out.
Sometimes it's good to make things to improve the designs, but sometimes wrong "improvements" may kill the designs.

Just MHO.

Cheers,

Louis

fusilier

The pipe is ALWAYS broken when you pull the oil cooler to get to the leak. The pipe is almost always in two pieces and the O-ring is baked or completely gone. You have to use a dental pick or something like that to pry out the bits of the old plastic pipe backed into the recess. Its Buna Rubber which doesnt have the termperature resistenace needed for its location. If the pipe was in good condition and not the weak spot then it would remove in one piece without fracturing into pieces.

As for the block thing... well the pipe goes into the block BEFORE you put in the oil cooler so I'm not sure what you're talking about there. If aligned right, the oil cooler will slip right over the pipe. No problems.

I have aluminum pipes if anyone wants to use it instead of the OEM part.