Engine internals may be destroyed..

[AMG]

I have changed my oil every 4000 miles and taken great care of my buddy but yesterday something went wrong.

I took the KJ out to post office and everything was fine until I came up to the stop light and that is when I heard a noise like it was marbles fighting in my engine trying to get out.....I put it in park and the noise became louder...then I put it back in drive and all hell broke loose and the engine died..completely. As I pushed it to the curb I could see a trail of oil. The tow truck guy thinks it was the rear main seal....

Well, do I waste time and let someone monkey with it or just buy a brand new engine?

 

[LibertyTC]

With rocks in a coffee can rattling going on and oil gone, so is that motor.
Rebuilding it could get very time and parts consuming.
Better off to find one from bone yard or already rebuilt. New? Big bucks.

 

[AMG]

thanks for the reply, well time to get a rebuilt

 

[Banditsteve]

Was there any warning lights on the dash before the rattling? Oil light etc? Could be a fault in the gearbox and not the engine? Things are not always black and white. Hope you get some good news from the garage. Steve

 

[AMG]

No rattling at all no check engine light either. my first thought was the gear box because the oil came from the back of the engine block. I will make sure before I drop the cash on a rebuilt.

 

[Banditsteve]

If there was no oil light, I am tempted to say it's not the engine. Even if the rear seal had gone, or any other seal or gasket for that matter, the engine oil light would have come on way before the engine suffered a melt down. The oil can't come out that fast under normal conditions. Have you dipped the engine oil since it stopped? My money is on the drivetrain somewhere. Good luck anyway. Steve :smokin:

 

[yellocoyote]

Mine had same/similar symptoms and it ended up being a dropped valve seat. The passenger-side head is at the shop being rebuilt as I type... which should remedy the problem.

I've also had some report that the oil pump fails without a CEL or any other warning lights.

A couple of things to investigate.

 

[AMG]

Mine had same/similar symptoms and it ended up being a dropped valve seat. The passenger-side head is at the shop being rebuilt as I type... which should remedy the problem.

I've also had some report that the oil pump fails without a CEL or any other warning lights.

A couple of things to investigate.

Ok I just crawled under the KJ and looked to see if the block has a hole or crack underneath it. I see no nothing at all. But I do see the where the oil shot out on the manifold.

 

[yellocoyote]

Well, maybe it's not the same scenario as mine then. I didn't lose oil... from anywhere.

You think it might be worth taking into a shop to have them diagnose before you sink the money into a new engine? I think I'd go that route.

 

[LibertyTC]

Jeeze Jayme, you still without the KJ...
You must be really missing the poor thing.
How much to rebuild the head?
Mine is currently parked as well waiting for the PML ****** pan to get here.

 

[yellocoyote]

Yeah... just over 4 weeks now. :sad72: I see it, looking sweet as ever, but inoperative in my driveway multiple times a day. It *****.

We took some extra time to talk to a handful of mechanics who know the ins and outs of this engine... compared price/benefit of rebuilding the head vs. replacing the engine. For now, the head will be rebuilt and reinstalled just so I can use it again. For the most part, I'll drive it locally. But come the fall, it will get a new engine. Need to save some funds first. I have every intention of keeping the KJ till it rusts out from under me (I'm simply not interested in any other vehicle out on the market right now), and would be more secure driving it back and forth across the country like we do knowing that there's a newer engine with some of the original design flaws worked out.

But, for now, I'm hoping by this time next weekend the rebuilt head will be back in and the jeep will be back out on the move again, where it should be.

 

[yellocoyote]

Just to have the passenger side head rebuilt is about $250 USD at a local shop.

 

[LibertyTC]

I just wish we could drop in the new Pentastar and be done with the old and in with new.
Overall though the 3.7's have been fairly reliable, how many miles did you have on when head problem developed?

 

[yellocoyote]

Over 170k on the odo now. Technically should be more than that considering the larger tires for the last few years... so if I do the math correctly, that would translate to nearly 180K miles.

 

[LibertyTC]

That is solid and reliable mileage. Were you running synthetic engine oil whole life?
In my terms in KM that is 300,000km=180,000 miles! My Jeep like new still at 40k miles.

 

[yellocoyote]

No, not always. Was running dino in it up until the last year or so, and then I switched over to synthetic. It ran like a champ up until the afternoon that it decided to quit. There was no warning, no CEL, no funny symptoms.

 

[LibertyTC]

I think once my Jeep hit 60,000 miles, I am going to run my own blend of 50% high mileage dino and 50% Mobil1 synthetic. In summer runs going to use 5-w40.
Just happy for you that is was only the seat and not valve/cracked head.

 

[yellocoyote]

As soon as I tried to start it and it was making bad, bad sounds, I shut it off. It hasn't been running since. I think if I would have persisted in trying to get it to run, things may have ended up differently.

 

[Banditsteve]

Ok I just crawled under the KJ and looked to see if the block has a hole or crack underneath it. I see no nothing at all. But I do see the where the oil shot out on the manifold.

Not sure which engine you have in yours, but where is the oil pressure switch located on yours? Just wondering if that has blown out which may explain a couple of things? Steve

 

[ridenby]

Think I would have it looked at before rushing into anything.