I couldn't agree more. Transmission fluid is made for transmisssions, engine oil is made for engines. Might as well put Tide in there, it's good at removing sludge.

Seafoam will do the trick per the instructions. Use 5w40 synthetic and a Big Kahuna oil filter (NAPA) and change the oil every 5 to 7,000 and you'll be okay.

You might also want to send in a sample to Blackstone Labs to see what's going on inside the Audi beast.

Blackstone Labs

I just had to change my oil pump with 220K on the clock. Now to get to the minor problems.

I have a 2001 with only 83k mi. but had sat for three years without running. I did all the recommended steps for a car that has been sitting before you start it but then ran into the oil pressure due to sludge issue.
I did the 10 min tre
Ans fluid flush, at 2000 rpm, no load (aka in neutral parked) then put in synthetic and a k&n filter and she ran well for 3 months.
Then on the way home one night, low pressure, starved my turbo and frayed it

I then dropped the oil pan and did the clean out myself replacing the oil pickup with a oem dealer pickup ($38). Oil pressure issue is gone.

Also, if you have a rattle from the engine on start up until the oil pressure come up, that may be your cam timing chain due to the tensioner not getting pressure immediately.
Once I did this, the rattle From the tensioner went away.

Hi guys i am new to the Audi platform! I am Very exited. Im currently looking at my optoins on exhaust systems, i like really loud and mean but very deep toned. Any guidance and advices will be great! Thanks everyone

Also, https://www.ecstuning.com/Audi-B5_A4...Engine/Filter/

See the large filters toward the end of the page. They work really well. I have also seen some where a 90 degree oil cooler replacement so an even larger filter can be used like a WIX 51333. If any one knows where to get one of these 90 degree oil coolers let me know. It would make a great kit.

This adds almost a quart of oil which solved the problem for me.

Were there any years that were more prone to the sludge problem ?
My 98 has 210,000 on it and is fine... change oil about every 5,000 miles.

Which engine? The longitudinally-mounted (Audi or B5 Passat) 1.8T has far more sludging (actually coking) than any other engine, because of the undersized sump and hot-running turb.

I wouldn't even worry about sludge with the old 12-valve 2.8, which is a very simple, nearly bulletproof engine. (I drive a 96 A4 Quattro, as well. I could easily afford to buy a new car, but have no motivation whatsoever to do so, as long as the Audi continues to run reliably. It looks great, is very comfortable -- except for rear seat legroom -- and is indeed a blast to drive.) Do maintain your PCV system and use high-quality oil. I use a high-mileage 10W-30 synthetic blend, with an annual change interval. Since I ride commuter rail to work, I do not accumulate a lot of miles with weekend-only driving.

Most important part of compression check is that the numbers be fairly close to each other. This will tell you if there's a broken seal or ring somewhere.