I've been reading all the posts about oil sludge, particularly on the A4 1.8, and I was wondering if there was any way to tell during an oil change how extensive the sludge build-up is. Given the comments, I assume this would be a gradual build-up that eventually is enough to clog the inlet. Has anyone noticed anything in their discarded oil that would be a sign of trouble?

 

Also, what are the symptoms and effects of it?

 

Your low oil pressure light will come on if your engine is sludged. It can be due to not changing your oil regularly, so as long as you keep up on your oil changes and DOCUMENT them, you should be fine because Audi will warranty your motor for 10 years, unlimited milage (if I remember correctly). If you want to see the amount of sludge building up, look at the bottom of your oil cap. If you have a finger full of goo, you may want to ask a dealer about the flush they do with the sludge kits.

In a lot of cases the inside of the crankcase breather hoses deteriorate clogging the pickup screen. On the older style, you can just poke at the one in the back of the valve cover. If it's squishy or if your finger goes straight through it then you may want to replace the breather hoses and suction jet pump. The newer hoses are more rigid, and you can't really tell what they're doing on the inside because the outside will stay firm. Just change your oil (and document it) on time and if the warning light comes on, shut your engine off immediately and have it towed.

 

Oh, and I also forgot. Audi has a larger oil filter for those engines so make sure you're using the larger oil filter. It increases the capacity and keeps the oil a little cooler from what I've been told. It does make a difference. Also 99% of the cars that are effected by sludge are automatics. I don't know why, but the manuals don't seem to sludge up as much.