compression test results: need opinion

INFORMATION Integra Help
1

just bought the $25 compression tester at advance auto parts and figured i’d check the car, just to make sure everything was cool.

the results:
Cylinder #1 210
Cylinder #2 205
Cylinder #3 195
Cylinder #4 220

is this telling me there is carbon deposit buildup? keep in mind i have an LS/VTEC, so i’m not exactly sure what idea compression is. stock for b18a and b17a are both 184 psi however, so i’d assume that’s what i should be about at

thanks for your help guys and gals

2

Are you sure that you got the right reading off of cylinder 3. Seems kinda low compared to the rest. The compression numbers all seem pretty high, especially the 220. What you are more concerned with is that the numpbers be within 15psi of each other. And you are a little low/high…whatever you want to think. How’s the car running?

3

i might double check it tomorrow, we were kinda in a hurry. but it seemed to test right at the time. the car seems to be running fine, except that for the past few weeks it’s seemed a little low on power. nothing major, but GStRing92 agreed with me that it seemed slow. i also recently changed plugs to the NGK BCPR6ES-11. shortly after that it got cold and now the car starts really rough, but smoothes out to ~1800 rpm until it’s warm. overall the cars seems to be running fine though.

4

Sorry Dan,
But I believe your value of 15 psi is very conservative The 93 Helms manual list the compression values for both the B17A1 and the B18A1 as 200 psi with a maximum variation between cylinder of 28 psi @ 250 rpm with a wide open throttle. Minimum value of 135 psi and normal value of 185 psi.

Now I realize he has a different head block combination, but he also has a different compression gauge which probably has some error and variation. The bottom line is you are still with in the normal range and it has been my experience the number 3 cylinder seem to generally have lower values due to being the hottest running cylinder therefore seeing the most cylinder wall to piston ring ware on an older motor.

5

as long as the highest and lowest are within 10% of each other your ok.

6

thanks, i know what the numbers are supposed to mean. that’s available both in the integra service manual and in the intructions for the tester. i’m looking for a professional OPINION here. the numbers seem high to me and i am wondering if anyone has seen these numbers on a car with carbon buildup or if they should be a lot higher, and also if the low reading in #3 is a problem or just typical, as someone mentioned.

those of you that offered good advice, thank you very much.

7

Thanks for the catch Marc. I meant to put 15%, not psi, which is near 30psi. OOPS. But still, like slacker said, I like my compression to be within 10% cylinder to cylinder. And it does seem like #3 is “marginally” low. Just keep an eye on it. Did you redo the compression test?

8

i’ve just been focusing on getting the car running so far. and still no luck!

9

for future reference however, will unhooking the positive power lead for the MSD be sufficient to prevent this problem again (assuming it was the MSD trying to output that cuased the problem)?

10

just got one too and slapped on a 95 b18b head on my 90b18a block. disconnected the fuel pump and removed all plugs.

first round, cranked like 3-5x each:
175
162
170
179

2nd round, cranked like 4-7x each until the needle didnt move anymore, twisted the hose in a little tighter:

199
189
192
198

i dont know what all this means, i forgot to put oil in the cylinders to see if the rings were leaking. i suspect the #1 cylinder got the highest reading cuz i put in new valve seals and cleaned out the valve guide thoroughly- but did these only on the 2 intake valves (bitch to put keepers back on without the proper tool).

11

Re: compression test results: need opinion

Originally posted by Habitforming
[B]just bought the $25 compression tester at advance auto parts and figured i’d check the car, just to make sure everything was cool.

the results:
Cylinder #1 210
Cylinder #2 205
Cylinder #3 195
Cylinder #4 220

is this telling me there is carbon deposit buildup? keep in mind i have an LS/VTEC, so i’m not exactly sure what idea compression is. stock for b18a and b17a are both 184 psi however, so i’d assume that’s what i should be about at

thanks for your help guys and gals [/B]

Based on your data and provided that your engine is in good condition, your compression ratios are as follows:

#1: 10.5:1
#2: 10.25:1
#3: 9.75:1
#4: 11:1

I’m assuming these are the numbers you are looking for. Again, this is your best case scenario provided the engine is in tip-top shape. IMO, the numbers are off quite a bit. You might want to do it again.

A couple of questions though:

  1. Are you consistent with your number of cranks per cylinder?
  2. What procedure did you actually do (step-by-step)? Yes, this may sound insulting, but it may enlighten us if you are doing something wrong.
  3. Are you watching how the dial reacts as it reaches maximum compression?

BTW, for the B18A1, 184psi. yields 9.2:1 which is stock. B17A1 is around 200psi. I think.

Regards,

Oz

12

Heres the way I do a compression test. On a cold engine loosen all 4 spark plugs but not too much. Now start the engine and let it warm up to normal. Now remove all the plugs and the ecu and fuel pump fuse. Then check each cylinder 3 seperate times and take the avearge. I consider it a good engine when the highest and lowest are within 10% of each other. Let the engine cool down and replace the plugs and fuses.