Odd compression test results.

[Run Away]

I compression tested my car not too long ago...
Results were:
1st 205
2nd 205
3rd 205
4th 215


Why so high? The factory manual says it should be at 180psi. It's a D15B2, with 168k miles. Oh yeah, the timing belt it also a tooth or two off, advanced.

My method was I pulled the ECU fuse under the hood and just cranked it over until it stopped reading any higher.

[inh]

with the cam timging off it will change your cylinder pressure.

[crazkene13]

Can be the result of carbon buildup in the combustion chamber as well.
More stuff in same space= higher compression

[bagpipe goatee]

All valid reasons so far, but another is that not all compression testers are the same. Some are slightly off calibration, some have different lengths of tubing, and some have attachments to adapt to different spark plugs. As long as it's even and not super low, I'd say you're perfectly fine.

My old a6 with BAD bore/ring wear (but still ran fine) scored 130ish across the board, for comparison.

[4CleanDoors]

^^^Great point.

On my mini-me, I was using just a generic tester to see what my compression was. It was giving me crazy numbers, and I believed them for awhile.

Then my buddy let me use his Snap-On one, and I was at 220 all across.

With inferior equipment you will get inferior results. Other compression tester wasn't making a complete seal, and was giving varying results.

[Mixelplix]

Also, what temperature was the motor? I can't remember for sure, but compression tests need to be done hot, right?

-Des!

[inh]

yea engine should be opperating temp

[Run Away]

Yup, the engine was pretty hot...I was at my buddy's house to use his tester so I had like a little drive to get there.

Thanks for all the responses guys..