just followed the compression DIY and I ended up with 195,200,200,200psi. This, after owning the car (1999.5 A4 1.8T) for 7,000 miles three 3K miles mobile 1 15W50 Extended performance oil changes(I'll be honest, I'm a hard driver), and not knowing what the previous owner did as far as oil changes (although he did have some kind of chip on it). This was when the car was hot from a 30min drive and I'd say the coolant temp was still reading middle way and the oil temp was a good 190-200 degrees.

The gauge I was using was a few years old but looked like it was in good condition (wasen't mine was borrowing it).. so I'm wondering if mabye I just happened upon a A4 with a brand-new engine or if it's the combination of good maintiance, testing when hot and the thicker oil that's giving me such great results. or if mabye the gauge is acutally drastically incorrect. Bottom line; trying to find out if anyone else has had similar results of high compression.


I re-tested twice, so the results are repetable. I really wish I had taken pictures now.

 

Maybe a rebuilt engine? try the compression test when the engine is warm, not hot.

 

. it was already sitting for about 20min before i acutally started the taking it apart and another 10min before i did the first compression test. so it was already cooled down a bit. u think i should wait longer? It was still hot.. but defentally cooled off a bit right from being turned off.

 

If you start the car cold, let it run for a few minutes, shut it down, then try it - that may give you more accurate readings. I hope you get the same numbers though - those are great.

 

I let the car run for 10 minuites and then re-did the compression test. My results were: 154,154,159,149... so assuming the gauge is correct.. when hot I have perfect compression. but when warm I'm close to needing a re-build.

 

You don't need a rebuild. Your #s are fine (very good with a hot engine), and you are using thicker oil than most. Using 5W30 or 10W30, I'd expect to see slightly lower numbers.