Compression test results.

[71smithja]

I did a compression test on my explorer yesterday. But i'm not quite sure of what the results mean. GOOD or Bad. My rig has 137,000 miles on it, and has been well maintained. The readings go as follows. #1. 167- #2. 198- #3. 198- #4. 172- #5. 192- and #6. 204. By standards, those should be good, but #1-4-5, jumped to 120 then climbed slowly to the max. #2-3-6, jumped to 150 and maxed out quickly. What i would like to know is, if this is o.k., or do i need to dig in deeper to find whats causing it. Any help with this, would surely be appreciated. thanks.

 

[90ranajo]

Your cranking compression should be within 10% per cylinder. Cylinder #1 & 4 are a little low (compared to the others) but still within 10%. I would do a leak down test to see how well your valves and rings are sealing.

 

[Sams01XplrSprt]

welcome 71smith

 

[AMMO_HOOAH]

When you did the compression test did you make sure to open the throttle to WOT and no air cleaner? I didn't the first time I did this and it did make a difference.

 

[BrooklynBay]

Welcome to this forum! I've moved your thread to the stock 91-94 section. There is a thread in the Technician Forum section with compression test results. Here's the link: http://www.explorerforum.com/forums/showthread.php?t=204909