Hunt For Low Compression (1 Viewer)

[Seth S]

I’d probably do a leak down test next. This can tell you if you have a ring problem, a head gasket problem, or a valve problem.

 

[BlackCat]

I am in Tucson AZ (2389 MSL), and I was hauling my Wife and I up to Sedona (4350 MSL) haha.

I was getting 110psi to 105psi for my compression numbers across the board.

I have not check my rings yet, I need to tear it down the engine a little further to see those but do not want to unless absolutely necessary.

My low mileage, original 60 can’t pull 50mph up 17 to Sedona. Just an FYI, I tuck in the right lane with the semi’s with my hazards on at 40-45mph.

 

[Seth S]

my 210,000 mile 84 with 31" tires, 4 speed, and original gearing can usually hold about 50mph on Killington Pass in Vermont. I have managed to tow a trailer over the less steep side and maintain 45 mph. But I've never had to let off the throttle on the way up because I was exceeding the speed limit. Climbing passes on I70 in Colorado was 3rd gear, 40 mph in with the big trucks.

 

[GLTHFJ60]

X3, leakdown test. My guess the valves/seats are worn, or the valves are adjusted too tight. Worse than that, rings weren't sized correctly.

This is all post-break in period, right? I wouldn't expect the compression numbers to be awesome until after the rings have been bedded.

 

[MoaByte]

@GLTHFJ60 , I was just about to suggest to check the valve lash. I was able to add 3 inches Hg on my vac gauge by adjusting my neglected valves. .008 intake, .016 exhaust.

 

[Seth S]

Has the oil and filter been changed after the break in? if not it wouldn't hurt to do so.

 

[HemiAlex]

326k with a known worn cylinder and a good tune. I Did 75 with my 4 speed and 33’s.

You need an immaculate tune up and a good gauge.