Zach2610

Ok I'm done with the compression test. I would like to hear what y'all think about my numbers and where to go from here. I know the range on the 4.0 is 120-150 Most of them are too high and I have too wide of a range I know. So here they are:

1- 140 dry- 150 wet
2- 155 dry- 165 wet
3- 165 dry- 170 wet
4- 160 dry- 170 wet
5- 160 dry- 170 wet
6- 155 dry- 170 wet

What does it mean if they are this high? I started at the front of the engine and worked my way to the back, so they lowest psi was the very front.

wildbill1

I've been told that compression numbers higher than spec can be from carbon deposits in the cylinders. Your high to low numbers don't look too bad to me. None of them are low. Maybe try a can of Seafoam to decarbon.

Zach2610

Alright, anybody else have suggestions? Ill try seafoam too

cruiser54

Run it.

cranesrule

Start. Drive. Stop. Repeat.

Zach2610

So seafoam, fix my oil leaks. Are my rings ok?

kjc

Did you check the compression with the throttle held wide open?

tjwalker

Higher than spec compression numbers can be the result of some inaccuracy on the compression gauge. Only way to find out for sure would be to run the test again with another confirmed reliable gauge.

But in general, nothing alarming there with your numbers. Anything more than a 30 psi variation starts to raise an eyebrow.

You don't mention WHY you tested your compression? Drive it.

Zach2610

Its in another thread, bad "ticking" at times, overheating and smoke

cranesrule

Maybe not then... Leakdown test? Check coolant for exhaust gasses? Obvious things like water pump, thermostat, radiator flush and cap first

Zach2610

Ok im still lookin into it