Orlo

Any of those repair prices seem like an awful lot of money to throw at a 96 unless it's otherwise in perfect condition.

Klutch

I read the post. Perhaps I'm missing it, but what I didn't get was:

- Did the compression significantly increase when oil was added to the cylinders? If it did, that suggests the low compression problem is with the rings. If the compression did not go up significantly with aoil added to the cylinders, this suggests the compression problem is with the valves.

- 163,000 is not a lot of miles for a 4.0. Granted, if the oil was rarely changed, that could cause accellerated wear with the rings and cylinders. But overheating? Possible, but not likely.

- Overheating can warp the head and valves. This seems more likely.

Thus, my suggestion would be:

- Perform the compression test again yourself. This is VERY easy to do and all it will cost you is some time and a compression tester, which is very inexpensive. You can buy one at almost auto parts store. You can find tutorials all over the Interweb. Basically, you remove all the spark plugs, thread the tester hose into a spark plug hole, floor the accelerator and crank the engine. Then you look at where the gauge is on the tester and write it down for each cylinder. Repeat the test after squirting some oil into each cylinder and note the compression for each again.

Red flags for this test are inconsistencies between the cylinders and a significant increase in compression after oil was added. Inconsistency between cylinders suggest the valves are shot. Again, a significant increase in compression with oil suggests the rings are shot.

- If there was no significant increase in compression after oil was added to the cylinders and/or there were big differences in compression readings between the cylinders, you can likely get away with a valve job solving your problems.

- If the problem is your valves, you can remove the head and take it to a good, local machine shop. They can rework it so it's as good as new for a very reasonable price. Of course, you will have to pony up $150 for a good gasket set. Buy a service manual and you can likely do this yourself. You can buy a nice set of tools from Home Depot to boot and still not spend nearly as much as it would cost to pay someone labor.

- If your rings are shot, you need another engine or an engine rebuild. Yes, you can sometimes find a good, used engine at a salvage yard. But there are a lot of people looking for a good, used 4.0. Also, you could get an engine that's worse than what you've got. Then you'll have to deal with the salvage yard who at best will give you another engine and under no circumstances will reimburse you labor costs for swapping engines. To be clear, I'm not saying this is a bad option. Just be aware of the risks.

- Buying a remanufactured engine is another option. More expensive than a salvage engine, but much less risky. Only you can decide what's best for you.

One more bit of advice: If you really want to drive an aging Jeep, you should really learn to work on it yourself. Paying someone else to work on it is not cost effective. It would likely be cheaper for you to buy a newer vehicle. I think most people would agree that working on an older Jeep yourself is part of the experience with owning an older Jeep.

tlang

Get a second opinion. If some one quoted you that on counter tops you would probably look around. If your vehicle is your life line I would assume its more important than counter tops.

Nothing against the first guy just being a wise consumer. Good luck

Pamelou

I want to thank all that replied. I have much appreciation toward all of you.
I do see oil on one side of the head, which is why I had purchased a head gasket for $60.00.
The mechanic told me that probably wasn't the case, yet, the compression did go down AFTER the wet test. This is why I wanted to get expert advice before making a decision. I'm really not letting my dog make this decision for me. Just made me feel better that he was comfortable and the hair didn't stand up on the back of his neck. That was sound advice as well, haha!
Like I said, I rarely have to add anything to it. It drives fine other than the rough idle, and feeling like it wants to stall at a stop sometimes. Not so much after its warm.
I think it must be a timing issue since both 1&2 cylinders are misfiring. My check engine light only comes on occasionally, with a key stroke reading of 1&2. I change the two plugs and it goes off, but idle doesn't get better.
I'm sorry if I've offended anyone with spelling and grammar. I'm more interested in my car then my use of English right now. I hope I'm not offending anyone with this post.
Just seems weird to me, that my car never breaks down while I'm driving it, only during the night when I'm sleeping. Which makes me wonder why I would need a whole new motor.
I'm going with the do it yourself compression test guy and get the head shaved and new gasket first. I may be here again for more advice, so some may want to check the posters name before reading as to not get your panties in a wad.*_*
Have a wonderful day!

Larry's XJ

Acknowledged ^^^ the smiley was the clue.

Three hrs sleep don't cut it for this old fart.

If it were me I would be doing more "Noggin Poken" on my own.
Clean throttle body, IAC (maybe new?) check and recheck for vacume leaks.
Clean electrical connections, have battery checked for load.

If it has thrown any codes straighten them out.
Presume new air filter with tune-up?

As mentioned a second opinion wouldn't hurt either.

Start checking/ohming sensors too

GreenManXJ

I agree with Larry. I really doubt it's a timing issue unless you had the distributor out when it started acting up or something. I've never seen something go "out of timing" on its own. I'm not sure why compression would decrease after the oil was added. Maybe someone else has an idea?

aj2494

I'm still not 100% sure the OP heard everything right. Follow your plan and do the compression test again, and let us know what you find. Test all 6 cylinders too, since that gives a basis to compare to.

tlang

Please dont just pull the head off. This is not for the faint at heart or newer mechanic and I can guarantee you will end up being more than the 60 gasket. In addition it may not fix your problem.

60 towards tools to diag correctly can go very far, you keep the tools and the knowledge.

Sideways99

Don't forget to check your grounds. Good luck

Klutch

If you paid $60 for a head gasket, likely all you got is the head gasket. To properly remove and reinstall a cylinder head, you need a head gasket SET which includes the intake/exhaust gasket as well as other gaskets.

Something is wonky with the "compression went down after adding oil" statement. This makes no sense to point where it defies the laws of physics.

Pamelou

Thank you, I'll exchange the gasket and get the set.

Klutch

Again, don't do anything until you've verified what the problem is. If your rings are shot, a new head or a rebuilt head won't fix anything.

As mentioned above, replacing a cylinder head is pretty involved. I just did it myself two weeks ago. It's a lot of work and it takes some know-how and skill. It's definitely doable, but your method should be 90% preparation and 10% action. Don't get those reversed.

BrawnyDog

Cough (Different from) cough

bullettooth2008

Too many words !

Rcrivolio

When it comes to large financial decisions (I'd consider this large), it's always best to shop around, get a few quotes to put in a used or rebuilt engine, and go with the mid priced option.

As stated before, there are boatloads of very good, even low mileage 4.0's in junkyards. I'd have one pulled and have it put in. I know around here (Illinois) we can get these engines for $250-500 depending on mileage.

Over heating twice to the point of smoking; definitely time for a new engine. Clogged injectors might have caused idle issues in the beginning but there's bound to be much larger issues now.