All,
I'm trying to troubleshoot a rough idle(+/- 10 RPM) low RPM performance loss on an N52/2006/70K miles. Symptoms include soot on tail pipe, so I thought replace DISAs, CCV and breather hoses (all look to be 2006 original). Decided to compression test before throwing a bunch of $$ at the car.
Are these numbers worrying? Specifically that the hot / cold PSI are close to each other? Edit: Re-ran on #5 & 6 cold and all the cold numbers are in line with each other.
Numbers hot[PSI]: 218.0, 221.0, 218.0, 219.5, 224.0, 218.5
Numbers cold[PSI]: 219.5, 225.5, 221.0, 223.0, 215.0, 211.5
Notes:
- Idled car up for 15 mins, temp gauge in middle to do "warm" test. Steam came out of tail pipe even after 15 mins but NOT white smoke, no sweet smell. Car has not been driven very much in the past year. Car had electronic water pump+thermostat replaced by previous owner when they failed, not sure to be worried about warped head gasket or not
- Cold test done with car sitting for 24-hours
- All EFI fueses pulled and all spark plugs pulled (per other forum postings on how to compression test)
- Using a brand new Mittyvac digital compression tester which automatically measures peak values
- Throttle body completely removed for both tests