Hi all, I've been searching all of the forum for the answer to this question, but it seems most people pay someone to do it or yank the engine. I wanted to know if I could re-ring my engine (or even better but less likely rebuild it) while it's still in the engine bay.

I've had massive amounts of blow by and oil splattering all over my engine bay, under-body, and drive-train. No joke. I've had serious problems holding any amount of oil pressure recently, and NEED to do something.

I tested my compression the other day and got readings from cylinders 1-4 (I have the 2.5L) of: 110(135), 140, 120(150), 160. The parenthesis numbers are when I added a teaspoon of oil to the cylinder, and according to the guide because the number went up, I have ring problems and a head gasket leak.

I ask this crazy question because I don't have a garage, or even a driveway! And people have real sticky fingers in my area so leaving it stripped in the street isn't an option.

In my mind, I should be able to pull the head off, drop the pan and do what I need to, including hone the cylinders. Correct me if I'm wrong, as I'm new to this

 

um , so, no driveway, no garage...where are you going to attempt this feat of McGuiverism?

 

Planning on front yard. I've gotten stupider things done before. Sucks when your poor

 

This won't end well...

 

It should be possible but will be an adventure. I've done some crazy curbside repairs in the past but nothing quite that major.

If the cylinders are badly worn though the new rings may not help much or last very long. You'll probably need a ridge reamer to get the pistons out. (Check for a ridge at the top of the bores after removing the head.) You'll want to be sure to keep dirt and grit out of the bearings which can be a challenge working out in the open.

You never know what you're going to find when you start pulling an old motor apart. A good used engine would probably be a surer bet if you can swing it.

 

Driveway 4.0 swap?

 

Save your money and buy a rebuilt longblock, swap in one day.

Even poor people can do amazing things.

 

Rings don't affect oil pressure.

 

I had to do something like this when one of the piston skirts cracked after 220k miles. I was able to do it in my garage though. I really didn't want to get into a full engine rebuild but I did end up replacing many things at the same time:
new pistons
new rings
new connecting rod bearings
new RMS

while the engine was left in place

I took the head and intake/exhaust off as one piece. Drop oil pan (read up on this one). Disconnect pistons from rods. Push pistons up through block. Reverse.

I didn't have oil pressure problem though. as others have said, rings won't fix oil pressure. That means other parts are worn that the engine needs to be removed to replace (crank bearings, crank,). In theory, you can pull the cam, but you'll need to pull the radiator for that.

So...it's doable, but will not solve your problem with oil pressure.

 

Very first thing I thought!

OP, I suspect you also have bearing clearance issues.

If it were me, perfect time to swap to a good used 4.0 that doesnt need a rebuild; just refresh and swap. I know you mentioned being poor, but I will tell you that what youll put in that 4cyl to be right that youd pay same or even less with a 4.0.

I got a complete 95 wrecked for $600
A complete engine, with harness and sensors, for $270
And another complete with harness, etc. for $75; tbf that one is unknown history

 

What is an RMS? Root mean square?

 

Rear main seal.


I see this build as one that will ending up costing you a lot of time and with little if any rewards even if it does run when you finish, ie. lawn ornament. This is not a first timers attempted build in any way.


Explore other options!

 

RMS = rear main seal.
I missed that this was the 2.5 and not the 4.0 I6. I think the rear main seal is a different procedure on the I4. I have a '99 Cherokee 4.0 and also a 95 YJ 2.5. My YJ has 140k and has not had to have the rear main seal replaced so I am not 100% certain on the 2.5 procedure.
The cracked piston skirt was on the 4.0 I6 engine which appears to be a fairly common problem.

 

 

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