Compression question, just trying to find the culprit of the low compression in my engine. So I have a d16y8 stock manual tranny with 190,000~ miles. It has like 110 compression across the board. I have just disregarded it for a while and now it's starting to bother me. I want to find a solution. I was first thinking bad piston rings but bad piston rings give off symptoms like burning oil and smoke from the exhaust. My exhaust gives out zero smoke and I don't burn a drop of oil so I threw that one out. Then I was thinking maybe valve seals but that too gives off signs white smoke I think. So I'm thinking maybe the valves are not sealing correctly. I'm not too sure. I have no problem ripping the head apart and giving a valve job. Anyone have any insight? Thanks!

 

The only way to really narrow it down from there is to do a leakdown test.

 

If the compression test was uniform across the board, I wouldnt worry about it too much. Do a leakdown test as recommended above and report the difference. I would also try the compression test again with a different gauge to see if the low numbers weren't a result of the pressure gauge used. I've always viewed the numbers as relative and as long as they were uniform, it was "good" to go

 

Okay, I will do a leakdown test tomorrow. Does it sound like it could be the valves not sealing properly though seeing as the other ones have symptoms? Thanks