I'm not much of an experienced internal engine diagnostic guy, working on a CF members rig and can use some feedback.

Did an engine swap on a 96 XJ awhile back, bought an engine from a NAXJA member during a partout. He did tell me it uses a bit of oil..

I got the Jeep back for other work recently, and he mentioned he's had to add a quart of oil since, the engine has somewhere in the area of 12-1300 miles since swap. It's also reading a tad over half quart low now.

During the swap i found the oil pressure gauge was inop, sender and cluster swap did not remedy. I just installed an Autometer gauge, pressure is ~55 psi cold and 25 at operating temps.

While engine was still at operating temp i did a compression test. All plugs removed, throttle wide open and fuel relay removed. Results are:

1. 135
2. 145
3. 150
4. 150
5. 150
6. 145

I didnt see the need to add a touch of oil in each cyl and retest since they seem to be within spec albeit cyl one being a bit low, but i read thats relatively normal. The front valve cover hose to airbox is wet, as it was when i swapped the engine.

Where should i turn my attention now? Valve guide seals? This engine has no leaks.

Thoughts?

 

You didn't say how many total miles this engine has.

 

Smoking? If so, when?

 

Nothing that you note seems too alarming for a used engine. Compression numbers are good.

A half court of oil to 1200 miles is really not that unusual.

Drive it and add oil as needed. Many engines go tens of thousands of miles with this amount of oil consumption.

I would not be concerned.

 

Thought i was pretty clear that it has used a total of 1.5 quarts over the last 1300 miles according to owner.

I dont know actual mileage on engine.

Need to finish up putting back together and check things out on cold start and while accelerating while warm, see whats coming out the tailpipe.

 

No smoking on cold start up or once warmed to operating temps... at idle or under load.

Only once and for just a moment i saw a tuft of white smoke coming from frontmost valve cover tubing heading towards airbox. No large stain on oil on K&N, no abnormal amount of oil on airtube to throttle body. Slight oil mist on inside of TB.

I guess i'll need to have my son follow me down the road once he gets home, see if it's smoking on engine compression braking since it's a manual?

I'm also gonna let it cool and check the tailpipe at cold start again, guess it's possible the valve guide seals didnt get much oil past them during the compression test. I should know for sure soon since i just ran it well up to temp.