On my 1988 22re 4wd pickup with 190K miles, I tested the compression at 220 215 215 215, quite a bit higher than the spec. How big a problem is this? Can I safely do my next trip of about 500 miles? I'm squarely in the camp of "if its not broke don't fix it". But is this broke enough that I should do something about it? What would you recommend?

(I didn't think to block the throttle open for the test, if that matters)

 

The even numbers show your engine to be in good condition.

I'd question the absolute accuracy of your tester though. But no matter.......

Drive your truck and be happy.

Jamming the throttle plate open while testing could have only made the test pressures read even higher.

 

I don’t understand how your healthy engine could read higher than spec which iirc is about 170 psi unless your gauge is faulty or you have an aftermarket cam or cam timing has been changed. In my experience, i’ve gotten the same readings with throttle plates open or closed. It just might achieve highest reading sooner when open.

 

Carbon buildup can increase compression.

Are you the original owner? I'm guessing a previous owner rebuilt the engine at some point and did some mods.

As long as the engine doesn't ping, I wouldn't worry about it.

 

Thanks for the info.

Iust got back from a three week trip, no problems. I've had the truck for 22 years, no major problems, no pinging. I'd read in my Haynes manual that carbon buildup could cause high compression, but I didn't know if it would be that even across cylinders, or would be that high. I think engine mods is the most likely answer. I'd never had occasion to suspect that any had been done. I'm the third owner. The original owner had installed a hefty roll bar -- that might be a clue about other mods he or she did. :-)

Next time I change the plugs, I'll retest the compression with a different tester, just in case the tester is off.

 

How are you running the compression check? Not all methods are the same. And do you know your gauge to be accurate? Lots of things could cause these unexpected results.

But....as others said, key is that the cylinders report similar readings. And if it starts/runs/drives fine, I'd not give it another thought.