Shark_Tank16

Hey everyone I need some help here. My 98 cherokee sport has had alot of troubles lately. After my own diagnosing and a quick diagnosis by some mechanics, I have a cracked radiator and blown head gasket, and they said most likely my head is warped and a whole new long block engine is needed. My jeep (currently at aprx 135k) has had an engine put in before (a low mileage engine put in at around 80k). I am the third owner so I do not know alot about why it was replaced by the first owner. But I have a feeling it could have already happened once before.

I was advised to obtain a long block engine with a steel head. I am not even close to a great mechanic, I also haven't been able to find out much about steel heads. I would like to know more about them and what would be a good plan of attack for these issues I have? I love this jeep to death and I know it could have alot of life left to live. I want it to run for a long *** time if I decide to put the money in to get it fixed.
Thanks, Mick

Cherockee

I would not take a "most likely" as a basis for making your next decision. It will not take a high level of skill to remove the head and have it checked out. Was there any coolant in the oil? Did the engine have low oil pressure? If there was no coolant in the oil and the oil pressure was good then i would replace the head gasket and the radiator (assuming it was leaking) and see where you are from there.

What exactly led to the determination that the engine is gone?

And let me add, no 4.0L Jeeps came with an aluminum head. Any long block will do if you decide to go that route.

Shark_Tank16

Thx, I agree, i'm trying to get second and third opinions here. my problem is that I don't have alot of time, i'm a 17cr 2 job broke college kid haha. But there is for sure coolant in the oil, the oil pressure is not too bad however.

It is the radiator that's leaking, there is a crack down the main seam.
The mechanics who looked at it was just one from local shop who charged me nothing to look at it, but said that the engine will almost always be done for if it gets hot enough to blow a head gasket. They said its not completely shot and i could replace the head gasket and radiator to buy some time maybe a year or two, but the engine would have to be replaced down the road. If it gets done, I want the job done right the first time and correctly so i'm not setting myself up for disaster. One of the mechanics has a lifted jeep and recomended a steel head so that was why i'm wondering about that.
The engine is not stock and the head is aluminum.

krawlthis

97+ 4.0 have aluminum heads. I have heard people have alot of trouble with them

5-90

No.

No engine had a "steel" head that I know of - by anyone, ever. Heads are either iron alloy or aluminum alloy (cast steel is uncommon - if it is in the engine, it's in the crankshaft and maybe some later camshafts.)

Also, no AMC I6 engine came with an aluminum head from the factory - the aftermarket aluminum head didn't come out until sometime after 2002 (because that's when the groundwork and information was laid - I know, I was part of that discussion.)

Replacement of the engine isn't strictly necessary for a warped head or block deck - the block deck rarely gets warped, and both surfaces may be ground flat (typically requiring removal of less than .010" of material.) It would cost less to grind the head and block flat again than it would to buy a replacement, once you find a good machine shop.

The heads that had trouble were the early #0331 heads (1999-2001WJ/TJ, 2000-2001XJ) before they were revised in late 2001 (revised heads have the "TUPY" foundry mark.)

Your 1998 will have the #0630 head, which is typically subject to uncommon individual defects rather than a class-affecting problem.

However, iron heads tend to be rather durable - you'd have to seriously overheat the things to warp them, and you'd probably have to loosen a couple of screws first! I think the only AMC engine that had major aluminum parts was the V4 used in the M822 "Mighty Mite" - which was an aluminum engine, aluminum body, and air-transportable.

Before I could give any more advice, I would think that some more tests would be warranted. What are your symptoms, and has a leakdown test been performed as of yet?

Cherockee

I'm glad someone with a bit more knowledge spoke up as I wasn't entirely sure what was ment by the "steel" remark, and I wasn't sure exactly what the OP is dealing with.

I hope you're not driving the vehicle right now. Coolant in the oil will cause bearing to start going bad...quickly. So if oil pressure is still good, maybe do the leakdown test suggested, then tear that thing apart. Looking at the outside of the engine is only going to tell you so much.

If your current engine has an aluminum head, that's kinda special. It would be worth it to have it checked out. But if its got a 0630 stamped into it on the driver's side top edge near the valve cover, then its not aluminum- seek another mechanic/garage.

Someone on here advertised a complete engine for $300 picked up so doing something like that would be a cheap way out if the bottom end of your block is shot, or if time and money are an issue.

hawaiian808

Didn't he say he had an engine change at 80k? Maybe that's were an alloy head came from?

Cherockee

Possibly. Seems strange to have a $2000 aluminum head 4.0L and not really know anything about the history of the engine. If it were replaced at 80K and he's got 135K on it now, that should mean the motor only has about 55k on it- cause who would put a $2K head on a non-rebult motor, right?

Rig looks pretty well built, and its very possible that someone spent some serious coin to build the engine.... only to have it destroyed by a cracked radiator.

Shark_Tank16

I'm having trouble getting information on it and am like i said not a great mechanic whatsoever. my old roomate who i bought it from is truly an idiot and really cant tell me anything about it so I in a way screwed myself over. Like Cherokee said, it is a well built rig with ALOT of $ put in buy the original owner. I am going to try and contact him somehow since my stupid **** roomate is in-capable of really helping me. I am not driving it at all and jus had it brought to my home in denver on a trailer where there are a little bit more options.

As far as symptoms go, I have not driven it far or long enough to get it too heated up, but there is an extreme amount of pressure in the radiator system. The coolant reserve tank bubbles up and alot of pressure is released when the radiator cap is slightly opened. Then I'm leaking coolant which is coming from that main seam, they also said parts of my radiator had actually expanded from the amount of pressure.
ANd thanks alot cherokee thats why I was so confused because all I could find doing research was the cast iron or aluminum heads.

Now that its home I am going to do the leakdown test tomorrow or sat and definetly try to take some things apart. Thats my only problem is time, but I have my winter break coming up in december and that is when some serious work can finally be put into it!

krawlthis

Your right, I'm wrong. Your goodlooking, I'm not so attractive