I recently bought this car and the engine was idling roughly. I changed the spark plugs to start with and it’s much better and gas mileage has improved. While changing them, the front 2 spark plugs had oil only on the threading. The back 2 didn’t. I’m a get in there and figure it out kind of gal but before I do that, I wanted to ask you what you thought needed replaced. Is it the o ring or an engine gasket? Or something else? I’ve only had it for 2 months and have had to add oil 3 times now. There’s never a noticeable spot of oil beneath the car so I don’t know if it’s just reducing way to quickly and if so, why that would be. I’m happy to share any more symptoms with you if you’d want to get more info.
What’s the difficulty level on changing the seal in the piston?
You have to tear the engine down. Then you may well find that in addition to worn rings the cylinders are worn and need to be bored oversize which would require fitting of oversize pistons and rings.
Follow up, what’s the difficulty level on the rebuild?
Very high. It is complicated, precision work. Something as complex and finicky as a modern Audi engine is not a good placed to start especially if learning on your own.
Dang. I’ve read more on it and I’m curious to see if the piston rings are worn. I’m curious enough to cut my nose off to spite my face too so there’s a really good chance I’m gonna go ahead and at least dismantle the engine so I can see what’s going on inside. I’m fascinated anyway.
A wet vs. dry compression test will give you an indication of worn rings without dismantling the engine. (Usually if oil rings are worn the compression rings will be worn as well, however sometimes that is not the case.)
Realize those are notorious oil burners. Now if the oil was only on the thread and not on the top of the spark plug then it's internal oil problems which means something's worn inside the engine on those two cylinders and eventually it would need a rebuild. But if the whole top of the spark plugs was wet, you could just need a new gasket for the spark plug tube
Dang, thanks. Yeah the people I bought it from told me they burn oil. I wasn’t expecting it to be this bad. I just needed it to get me by for a while so hopefully it’ll hold off for a bit. The engine seems pretty accessible. What’s the difficulty level on changing the seal in the piston? Follow up, what’s the difficulty level on the rebuild? I’m no stranger to things like spark plugs/wires/brakes/rotors/calipers and the like but I’ve never taken apart an engine.