Water pipe failure...Potential disaster, Averted

[therealnovaboy]

After yesterdays escapades I thought Id write up what has happened to make s4 owners aware of this possible problem.

When doing a routine oil change I noticed a steal pipe running from the oil cooler weep coolant. On further inspection it seems that the metal pipe has corroded through to a hole. Realising that the pipe would have to be taken out and replaced I proceeded to turn the pipe in every possible orientation to try and slide the pipe out from between the front engine mount and block. However this was not possible without removing the front end and taking off the front engine mount. I made the decision to cut the pipe in the middle, slide it out and then fabricate a new pipe. You can see from the pics below that the pipe was very close to complete failure in several places, which would have resulted in very warm oil and possible engine failure.




pipe removed and cut in half

close up of corrosion


pipe was cleaned up to find many small holes and thin pipe walls



new pipe made up from copper pipe and yorkshire fittings


fabricated pipe in new location under engine mount



it would my advice to check this component during a timing belt service interval as change out at this time would be straight forward.

 

[Matt82]

does your car have its engine under tray still?

 

[therealnovaboy]

yes. but it had to be removed during oil changing and pipe replacement. i will keep it removed untill i am sure there are no more leaks.

 

[Matt82]

thats really interesting then. id have thought maybe stone chip damage could have started the corrosion on that pipe. maybe something was spilt all down there in the past and started the corrosion.

bullet successfully dodged

 

[therealnovaboy]

no the standard pipe is located further up out of the way. if only audi's leaked more oil then this would probably never of happened. l0l

 

[aragorn]

I'm not sure about using copper pipe on an engine...

Copper tends to work harden quite easily and would then fracture...

 

[phoenixv6quattro]

I can vouch for that, fabricated some copper pipe for my old 21 turbo. Lasted under 3 months before ******* everywhere!

 

[aragorn]

Ye, the pipes only about 20 or 30quid new from audi by the looks of it...

 

[phoenixv6quattro]

Nice write up though buddy. Its good when someone takes the time out to post pics etc to make other owners aware of the potential problem, and gives them the heads up on how to fix it! FAIR PLAY.

 

[therealnovaboy]

yes twenty to thirty quid is cheap but it would take hours to remove the front end to get the replacement pipe in place. which was not a job i was looking forward to do to replace one pipe. the copper should be fine i made a bracket to hold the copper from moving and fracturing.

 

[aragorn]

keep an eye on it...

 

[phoenixv6quattro]

A very alert and watchfull eye.......

 

[Geeman]

I had to have this very pipe replaced on my A8 2.8 as it was losing water through the same part!

 

[heymynameismark]

Good write up that! Well done. As said, keep an eye on it though!

 

[olds_cool]

Would my 2.6 quattro have the same pipe as I'm loosing water and can't see where from ?