I am going to do a routine compression test in a little bit. What number range is probably healthy for a stock D15 with 200,000 miles?

And I know that is doesn't nessacarily matter how high the numbers are, just as long as they are all uniform, but I know that there probably is a healthy range.

A year ago I compression tested an it was all within the 160 range I think.

Thanks...

 

Nominal=185 psi
minimum=135 psi
maximum variation between cylinders=28 psi
{info from '88 Factory service manual}

Compression should be tested with engine at operating temperature,
All spark plugs should be removed before testing..
Good Luck,

 

what happens if theres more then 28psi difference in one or more cylinders?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">any variance between cylinders means a greater variance in the output of the individual cylinders. Simply stated, the engine is rougher than it needs to be if the compression ratios are not balanced between the cylinders.</TD></TR></TABLE>

It may cause the engine to run rough,be unstable,have drive-ability
problems etc..

 

Yeah, I heard it was something like there shouldn't be a 10 percent difference. So like if there are two that are 155 then the others shouldn't be like 15 less or more or whatever. But 28 psi sounds good too!

So if normal PSI is 185 then how much should it be at right now and still be healthy?

 

I have a d16a6 that was in my old 91 si, and I then bought back later after I did a swap for the kid I sold it to. But when I did a compression test on it, it was 205 across the board with a Snap-On compression guage.

 

Wait, but wouldn't the compression on that be different then my stock D15B2 though?

 

yeah probably. my b16 put 190 across the board.