I tested my compression on my 89 crx si motor and my compression wasfrom right to left) 125, 125, 100, 125. i know that the third one is low but what would be wrong? no oil gone, no antifreeze gone, still hauls A$$ but is 125 low for si motor? is there anything I can do for the 3rd cylinder? some sort of valve cleaner? my valves are pretty loud. I am doing that tomorrow.
Thanks for you help,
Tony

 

I have a 91 si and my compression was as follows 155,150,150,150

 

Those numbers are a little low. I got 180/180/180/185 on an 88 D16a6 with 120k on the odometer.

 

even the chilton's manual said it should be about there... I can still hand a civic ex it's a$$! The chilton's said if one cylinder is unusually low the drop a teaspoon of oil in to that cylinder and try it that way. I dunno, no oil loss but I think it might be bad valves or something is keeping a valve from closing all the way. The weird thing is, all of my motors have had between 125 and 135. any other ideas why this is? thanks for your help guys. if you need anything let me know. I will be glad to help. Also, if anyone needs some parts for a crx e-mail me of call. I have a whole parts car that I need to get rid of. (it's already apart, so don't ask for the whole thing . )
Thanks,
Tony jdmcrx1@yahoo.com 402-208-4061-cell

 

i would say there are many variances when doing a compression test.

it's not about getting high numbers.. it's about getting pretty consistent numbers

 

leakdown test.

 

are you sure you read your chilton correctly? my Helm manual for an 89 CRX Si says that the normal compression is 185psi and minimal is 135psi. The maximum variation between cylinders is 28psi.

 

I would guess carbon buildup on the valves not alowing them to close all of the way, but that's a shot in the dark guess. As long as you're playing around with your valves, make sure your valve lash is properly adjusted. #3 (or all of them for that matter) could be too tight, which would also not allow the valves to close all of the way.
Check my sig for a link to parts I need and see if your parts car can spare them, thanks.