Blown engine, options?

My T-stat failed, engine overheated and blew the head gasket. And I got my driver's license yesterday. Ii'm not the happiest camper. Anyway, what are my options? It was the 4.0 L 1998. I could buy a new 4.0L, which is my last resort, buy a Titan stroker, I might do, but if there's a fairly simple (relative, obviously) engine swap I'd prefer to do that. Any options?

um....why dont you just replace the head/head gasket? what other damage did you do that you're not telling us, besides the head gasket?

To be honest, nothing. I learn how to work on things by taking it apart and figuring out how to put it back together, and I haven't done an engine rebuild yet... The guys at Pep boys told me I would need a water pump, serpentine belt, distributor, rotor cap, all that stuff. I asked why and they told me "because that's what you do when you change a head and head gasket."
The block may be cracked, but if it's not can I get the deck milled and a new head and head gasket?

water pump, tune up, etc?? nice but not necesary. the only reason to change the water is if that was the cause of the overheating .remember those guys are there to sell parts.have the head checked for cracks & warpage, have it milled only if it needs it & put it back together. get a chiltons or a haines book & your'e good to go, or spend the big bucks & buy a rebuilt head. 4.0 engines go forever. if you need the deck milled then you replace the mtr, but thats highly unlikley.

you could just put a jet engine in it... but i think that rebuilding the 4.0 would be a little more cost effective and probably more reliable off road.

Before you spend a ton of money,you might want to learn to drive first.That means paying attention to little things like the gauges(idiot lights)!

I don't have idiot lights I do need to pay attention to the temperature guage though.
So take the head off, can I check the block and head myself for warpage or is it something you test for? If they aren't warped, and the block isn't cracked, all I need is a new head gasket. If the head is warped, get it milled, and the same thing goes for the block. I'm assuming once I get all of that sorted out I should do a compression test to see if the block is cracked?

You have a haynes manual right? if not go buy one. The first time I blew out a motor like you just did I bought one and I had been my Bible for a very long time. you can fix that baby easy. it wont even cost you much. Find the local "Pick-N-Part" they usually have half price deals on Wednesdays and Sundays. Go buy a new gasket from one of the auto stores, or online from Summit ( I just said them randomly ). With a friend or yourself, you can do the whole job with only a couple of bruised knuckles in a weekend.
Shoot PM and I can walk you thru the whole thing on the phone no biggie. I do that stuff all the time and as we speak this weekend I am doing a new motor in the battlewagon.
I bet you can be back on the road for under a couple of hundred, maybe less.
I have some of the big nasty parts I would love to be rid of if some was really messed up with your motor, like an extra block or something. I would be glad to rid of my extra big parts!

Post some pictures of the motor. post picturse of the water and of the oil on the dipstick. How exactly do you know the headgasket is blown out? It will help us help you.

Replace the had gasket, check the head for flatness.

Unless you want a pile of crap engine, don't buy a Titan. I have one... my XJ hasn't moved for 3 months.

:lecture: compression test is pointless w/blown head gasket, the big question is how long did did you run the engine after the gasket blew? cast iron cylinder head are pretty sturdy units & will take lots of abuse. most of the head gasket horror stories you hear are aluminum heads not cast iron. we love our 4.0 jeep engines because they take incredible amounts of abuse[ and lots of torque & power].check for warpage with a carpenters straight edge. you need to have a machine shop magnaflux it for cracks if you ran it very long. most shops will do this for no charge if your cyl head is clean. if its not warped it,s probably not cracked. the cracks usually occur between the valves & sometimes you can see them with the naked eye, 4,0 blocks dn't usually crack from bad head gasketss. it's very unlikely.

mk153smaw said:

You have a haynes manual right? if not go buy one.

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He probably already has a working doorstop somewhere. Go get a Jeep Factory Service Manual. About $100 new, $40 ebay, or free if you search the seedier parts of the internet.

I do indeed have an FSM. I only drove it for like 10 miles I THINK, looking back I remember the engine sort of shut down, it was exactly like if I let off the gas, I just didn't let off that gas... I did look down at the tach and I didn't specifically look at the temp gauge but I also didn't notice any gauges that were pinned (like the temp gauge). I noticed the temp gauge was indeed pinned about 6-8 miles later and immediately pulled into pep boys, shut it down and put the hood up. I'll check the oil in a minute and get back to you guys. i do know that the guys at pep boys tested the coolant, and told me "when the tester fluid is this color, you have a blown head gasket." So I'm assuming I have oil in the coolant.

Assuming the head and deck don't need milling and the head gasket gets a good seal, couldn't I run a compression test once i replace the head gasket to see if the block is cracked?

edit: I just checked my dipstick, and the oil looked completely normal... Could it be milkshakey in the oilpan but not on the dipstick?

mk153smaw its good to see another XJ'er in the DFW area. You part of LSJC?

derrickdrew17 said:

mk153smaw its good to see another XJ'er in the DFW area. You part of LSJC?

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yes I am, I was up at the Barnwell Jam over Memorial Got those XJ springs

Ok back to helping this guy...


If the dipstick is not milkshaked, you may not have such a bad problem.

Never trust a guy who just says a statement of the nature that the Pep Boy's guy told you. There is a chart for reading the color of the coolant and he should have refrenced it and told you word for word what it said. If it then confused you, then he should lay it out in laymens terms. When I supervised my mechanics I used to explain to them for thier own good it is better not to short cut anything, not even when trying to explain stuff; Just grab the manual and read it.

It might just be a bad bearing at this point and can be fixed a number of ways, some expensive (having someone else do it) or cheaply (you do it).

Where do you have the Jeep right now? Is it completly dead? (sorry I forgot, been a long weekend...) What kind of lift do you have? With a 3" lift you can take the oil pan off super easy and do a check a lot of people do not like to do, but it might help you here. If it is dead right now, I would pull the pan and pop one of the rod caps or a main and look a a bearing and check the wear. If it is just a siezed bearing issue then you have just a problem that is less than $100 to fix and a weekend of you time hanging out with a couple of buddies getting a tan in the sun while you bust your knuckles pulling the motor to change the bearings. Really, it is fairly easy to do. OR.... You can say screw it and go to a local junk yard see if they have a short block on the ground or easily removed from an XJ and just switch it out. That can usually be had for around $100 if the place does not suck.

I like to think of myself as mechanically inclined, my whole family races porsches and I've been working on them since I was about 10, so I can at least hold my own.

I picked up a new T-stat today from Pep Boys, my dad was hell bent on getting the 180 degree version and since he's nice enough to pay for this I figured I would go for it. I installed it without a hitch, but now my battery's dead. Stupid Winch/lights/sound system... It's charging now and when it's all charged again I'll let you guys know what the deal is.

It's sitting in my driveway hooked up to the battery charger. I have a 4" lift, instead of pulling the whole pan what if I just pulled the drain plug into a container?

I replaced my head gasket a couple of weekends ago, Jeep runs 100% better. I wasn't replacing a blown headgasket, just trying to fix oil leaks, and so far so good. I recommend that if you are going to pull the head off, to get it hot tanked, or take it to Napa (or your local machine shop) and have them clean it chemically. If you do this, just have them check it out for you to see if the head is warped.

The amount of work total I did on my engine was probably 8-9 hours, no experience with replacing head gaskets or anything. It is pretty self-explanatory, but a Haynes or Chiltons helps a lot.

If you can prevent taking the oil pan off, do that. They are a PITA to get back on with the gasket lined up correctly.

with the over heat, checking the bearings becomes important. You might have worn them down with the eccessive heat, which will lead to bad problems later. Your racing experience should tell you that.
Drain pans are like panties on Jeeps, better get used to dropping them.

if you drop the pan you should consider replacing the rear seal.it's a 2 piece & the hardest part of the job is dropping the pan.I think all 4.0s with over 100k have a leaky rear seal especialy if they've been run hot.

I agree with replacing rear seal, there are plenty of write-ups on how to do it. I had to buy two, screwed the first one up. Good thing they are cheap.