Just bought a 99 sport with 140 k on it. While driving it home from seller, temp gauge spikes, gauges light comes on. I slow down, turn off climate system (heat) and pull over. Pop hood, nothing, no smoke, no fluid. Call seller, he says try and get it home, but anything over half is not good.


I limp it home at 55 mph, temp gauge never going past next mark after 210. It stayed right in between half and the next the rest of the way.


Get home, check all coolant hoses, all hot meaning circulation. I can hear bubbling/gurgling under radiator cap.


Wife is PO'ed, thinks I bought a lemon. Lol


Call the seller who is also a mechanic, gives me a list of things to have my mechanic check, first and foremost, tells me to get a sniff test to check for Co2 in coolant to check for a blown head gasket.


Sniff test reveals CO2 in coolant. F...99% blown head gasket.


Seller is sending me $300 (for parts) to help with repair. (much more than I expected, he could easily tell me to go pound sand)


My mechanic quoted $1100, including milling and parts. I've already ordered Fel Pro gasket kit w bolts for $130 from Amazon.


My question is the head, I've done a ton of research and depending on when it was built, the 0331 heads are known for cracking. My mechanic is going to see when it was built and going to look in the oil cap to see if he can see the "0331".


If it is the "0331" but not cracked, should I go ahead and replace it because it may crack eventually?


Is there anything else I should replace while its in the shop and opened up?


Thanks,
Ben (FNG!)

Get this head- $445 and send back your cracked head.
http://www.ebay.com/itm/NEW-JEEP-CHEROKEE-LAREDO-4-0-0331-CYLINDER-HEAD-/160887572206?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AJeep&hash=item2575a586ee&vxp=mtr

The likelihood of a 0331 cylinder head on a 99 XJ is extremely low and will take less than a minute to rule out. You probably have a 0630 but might have been warped beyond repair depending on the severity of the overheat. Plan on the cost of a machine shop to evaluate the condition of the head. Either way $1100 sounds way too high for a head gasket replacement. That's closer to the cost for a cylinder head replacement. You should also take this as an opportunity to do a complete overhaul of the cooling system. Didn't you test drive the Jeep prior to purchase? Sorry to say but it looks like the PO pulled a fast one on you. Keep us posted.

A mechanic's vehicle is the worst one on the road.

He knew and now he feels a little guilty.

Under no circumstances would I ever use or reuse or use a "rebuilt" 0331 head. You cannot fix or get around the original factory casting flaw.

Clearwater makes a reinforced casting 0331. It's not prone to cracking like the original casting.

OP if you're close to Connecticut I have a few 0630 heads sitting around that I pulled off running driving XJs.

You can do a quick check to see if you have a 0331... just look and see if you have coil packs on each cylinder. The 0331 uses them, the 0630 does not.

You can definitely have a 0331 in a 99. My local JY has one that I have been scavenging interior parts from... same problem. 140K blown head.

They began to come out mid-year and on. It was not common, but they were out there. If I were you, I'd ditch the 0331 and get a Tupy head if you can find one.. or like Cobramarty suggested

Just a little more info on it... hope it helps if that's the problem.

http://www.bobistheoilguy.com/forums...2752985&page=2

Are they willing to give you a lifetime guarantee in writing that their re-engineered head won't crack?

If it needs a new engine, a cylinder head (of any type) won't fix it. Just wondering if it was overheating why you kept driving it & didn't call for a tow?

The temp needle spiked, check gauges light came on. I slowed down and within a few seconds, the needle went back to normal (just above 210) and check gauges light went off.


Pulled off Hwy, checked everything, no leaks, coolant level was fine. It didn't do it again the rest of the way home.

Jeep was made in 3 of 99 with the 0630. Hopefully the temp spike didn't cause any head damage.


It never did it again and the temp stayed just a touch over 210 the rest of the way home. Heat blasting and climate system completely off.


Question-


Do you think the head gasket was already blown but only reared its head when the temp got hot?


Or did it blow when the temp spiked on the way home and then went back to normal??


We thought maybe there was a bubble in coolant system because they had to tighten clamp on hose because it was leaking when we got back from test drive. Also thought maybe thermostat got stuck, causing temp to spike and then released, bringing it back down to normal.


Dunno?? Thoughts and opinions welcomed, but go easy on the newbie...


Also, is the temp a touch over 210 normal and what's up with the oil gauge falling when idling, then going up when accelerating and all that?


I picked up keys from shop earlier and I'm going to get it tonight to bring back home to await parts. She sure is pretty and I can't wait to get her on the road.
Thanks again-
Ben

Oil pressure rising and falling with RPMs normal.

In my opinion, above 210 in your location this time of year is high.

So, mechanic calls today, says Jeep is ready to go, just need to get state inspection today and probably be ready tomorrow. The head was warped a little, so machine shop evened it out and got it sealed tight. I also replaced the radiator because the bottom 2 in temp was 90 something while the rest of it was much hotter.


Now it gets interesting... mechanic tells me that "there was no thermostat". I'm like huh? Really? He was said yeah, nothing there so obviously we put in the one I bought when I first got jeep, thinking (hoping) that was only problem.


I said why would that be? He says maybe because the guy you bought it from or the guy before knew gasket was blown and taking out thermostat would assist in not revealing that right away.


Anyone ever come across something like that?


Thanks,
Ben

All the time...
Something of a last ditch effort to try and make a blown hg last, but really doesn't make a difference.

Thermostat controls the minimum engine temperature, not the maximum, best of luck to you.