I used to put 6 oz. of Seafoam into the oil 75 miles befor a change. I used Mobil 1
10W-40 and never had sludge. The oil was changed every 10K mi. The car now has
180K mi. with a new owner.

 

I just purchased my first Audi. Been a BMW guy for as long as I can remember having owned three 3 series. But this week I bought a 96 A4 with the 2.8L motor with 112,000 and am very happy with the way it drives. However, when my mechanic was looking it over he showed me the sludge issue and we are going to do a flush on it a couple times and use the solution you guys have been mentioning to break all of the sludge free. My question is what weight oil works best in this motor and whether you guys are using fully synthetic or just high mileage oil?

 

5w-40 synthetic is recommended and is what a dealership puts in 90% of audi engines

 

Isaac,

I've owned my '98 A4q 2.8 since it was new. I don't think the Audis came with synthetic oil back in those days. I switched to Mobil 1 (10W-40) synthetic oil immediately after completing break-in and have changed the oil and filter every 3,500 to 4,000 miles ever since with no regrets and no stories. I have been using the Mobil 1 (10W-40) High Mileage since about 90k miles. I now have about 150k miles on it and still love the car. You can buy 5 quart jugs at Walmart. Use a high quality oil filter.

 

If you use that insane oil change interval of 15K miles recommended by Audi, you are sure to get a sludged up engine. lol

 

What would be a good result from a compression check? Will they just tell me "you have high/low compression" or will they give me some sort of number?

 

I use Mobile 1 5-40 High Mileage, and i change ever 3k miles, do you think this is too often? Think i could make it to 4 or 5k safely since its synthetic?

 

i change mine every 3500 miles.. i vagcom'd the service interval to start there instead of 5k..

as for compression check. that wont tell you much, because there can be many variables that affect compression. such as, bent valve, worn rings, bent rod, or headgasket.

but if your still inclined to check, I did mine a few months ago and it read out 210 +-5 for each cylinder. the tolerance is ~20% for each cylinder. so if one read out 210 and the next read out 180 or below, i would be concerned.

 

putting trans fluid in a engine and running it for a small amout of time is fine. if a tech is adding trans fluid and your driving it regularly your asking for problems. trans fluid has a seal swell agent, that agent can ruin internal parts. id reccomend adding the same amout of tranny fluid as you would oil. start it up. let it idle for 10 minutes, and drain. refill with engine oil and repeat that same process. guna take like 8 quarts but id never in my life drive around with trans fluid in my engine. trans fluid goes....in the trans. that should get most of your gunk and other junk engine oil wouldnt regularly clean, thank you trans fluid detergents.

 

a tech is doing this. imo bad idea. if your running it parked, but driving around with that **** in there? no bueno.