[mick]

I have 130 psi on all 4 cylinders. How much longer should this engine run? How many miles? How much power am I losing?

 

[rogoman]

At that compression, the motor can probably last another 100,000 - 200,000 mi. However as you put more miles on, the compression will continue to drop further along with the power loss.

As far as power loss, you've probably lost approximately 30 to 40 HP.

 

[mick]

Retested

I retested the compression after replacing the timing chain. It now reads 150-150-150-160. Would the difference in one cylinder be noticable?

 

[rogoman]

A difference of 10 psi would not be noticeable. The FSM states a 14 psi differential limit between cylinders so you're OK.

Are you doing the compression test correctly? While testing a cylinder, make sure the throttle valve is fully open.

 

[mick]

Compression testing

My mechanic did the test. At first it was 130 across. Then he changed the timing chain and said it was 150/150/150/160.
All I know. I will ask him about the throttle.

 

[Nismo240]

i'm not 100% sure, but i think a stretched timing chain can cause a loss in compression. i believe that the chain on my SR is stretched and i couldn't get it to read at all when i tried to test mine. so i could see it helping out in your case.

 

[mick]

If the valve timing is off then compression would be affected cause some valves would not be fully closed. But I haven't heard about opening the throttle when testing.

 

[Nismo240]

yea, you're suppose to have the throttle all the way open when doing it.