884x4

my 88 4.0 is dying
264k

dry
1-167
2-125
3-178
4-172
5-170
6-173

wet
1-215
2-172
3-202
4-190
5-190
6-205
looks like my rings are shot beyond belief
and whats up with cyl 2?

salad

Nothing wrong with those... if anything the test was done wrong. Factory service manual method is like this:

- Start with a warm engine
- Disable ignition and fuel system
- Block open throttle plate to WOT
- Measure compression on the THIRD stroke

Using this method a 4.0L in good condition will be around 120 PSI. The specification is that all cylinders should be within 20 or 30 PSI of each other.

If anything looks like you've got a top-end problem in cyl 2. Valve maybe.

884x4

opened throttle to WOT unplugged fuel pump relay, and coil wire, i think I measured compression on the third stroke, my understanding is there shouldn't be a huge difference between wet and dry tests?
theres about a 50 psi difference on cyl 1?

Bustedback

How does it run? Good? Don't worry about it, just drive it.

Willys55

I would rerun the test for cyl 1 again just to be sure, but I agree with salad.

884x4

the reason I did the test is because 1 qt of oil is disappearing every 100mi with no explanation. no leaks and im using rotella 15w-40 with napa gold filter

mentalbreakdown00

could be valve guide seals. Do a leak down test and see if its rings or valves or what

Bustedback

Check and clean the CCV system.

884x4

new ccv everything about 3 months ago, zero oil in the air filter

884x4

will do, thanks