View Full Version : Sludge Theory...

06-10-2007, 03:59 PM
So I have an A4 that ate the big one. I didn't drive it to the ground, the previous owner did. The 1.8t that is currently in it is shot.

My question is, after I put a reman/used or whatever engine into it, where is the sludge coming from? Are these turbos oil cooled? I want to find the solution to the problem, rather than just putting an oversized filter into it, and pray that the oil never cakes up.

My thoughts are :
Larger oil line plumbing to, from turbo, maybe more volume of oil hitting the turbo will keep it from getting so hot, thus reducing sludge.

Converting to water cooled turbo

Any thoughts, feel free to add.

I haven't done much searching. So if this has already been ranted about, feel free to flame.

06-10-2007, 04:29 PM
Ummm, already water cooled... Problem has already been taken care of... Use synthetic oil...

06-10-2007, 06:40 PM
using the large filter that napa has i think the part number is 1337 but just check they call it the big Kahuna or something like that.

1.) bigger oil filter - acts a to cool it not only because it is big but hold more oil
2.) synthetic - better stability
3.) change your oil
4.) properly cool turbo after a hard drive so you don't cook the oil in the turbo
5.) run auto-rx every couple of years
6.) stay paranoid so you over take care of your car

06-10-2007, 06:46 PM
I cool the turbo down by driving 25 mph for the last mile to my house and change the oil every 7000 miles. I have a 99 grand cherokee with a sludged up oil fill tube-it's just from the cheap ass oils that the quick change places use. Use a good synthetic oil and don't run 1 bar and pull into a parking lot and shut it off right away.
All that other stuff can't hurt either.

06-10-2007, 08:33 PM
Use a good quality synthetic and you should be good.

06-11-2007, 06:07 AM
The problem is a combination of factory recommendations and choices. Conventional oil, long change intervals, and a tiny oil filter add up to a sludge issue. If conventional was changed every 3k miles or synthetic specified at the existing intervals it might have never been a problem. A larger filter is always nice.

06-11-2007, 06:12 AM
The turbo isn't the problem. Running larger lines to and from the turbo will cause more harm than good. Use a full synthetic oil and change it and the big filter every 5k miles. Prefill the new filter about 2/3 full before installation.

06-11-2007, 07:25 AM
IF you remove your oil pump and see how clogged your pickup screen is you will understand your sludge problem. From using non synth oil it turns to what almost looks like burnt coffee grounds or sand all stuck in your pickup screen. I did flush after flush which helped for a week at a time. Then i just did the oil pump and had no problem since.