n_co

Hi,

New here. Haven’t found post about this but feel free to direct me if there’s already one out there.

ive got a 2001 Jeep Cherokee 4.0. Local automotive shop tells me there’s a head gasket leak. I’m thinking about fixing myself. But how do I know if I just need a head gasket repair or if I’ll need a new cylinder head? I feel confident about replacing the head gasket but not sure about the cylinder head.
Also, once I open it up I’d hate to wait around to have a cylinder head shipped to me.

any suggestions?

thanks.

tech

If you have the 0331 head from 2001 and it has not been replaced with a after market head or the newer 0331 head that has tupy cast into it I would change it because they will crack and leak coolant in to the oil . I went to a pick an pull and got a head off a 2004 grand cherokee 4.0L that has the tupy mark on it and just cleaned it up reseated the valves and put in new valve seals and check to make sure the valves did not leak . Then installed it and no problems , I'm no longer loosing coolant .

BlueRidgeMark

First thing is to identify which head you have. Do a search on TUPY head" and you'll find a bazillion hits. They had a flaw in the casting which made them prone to failure. If it has the classic failure, you can actually see the coolant seeping out of the head by pulling the oil cap and looking in with a flashlight.

Other than that, there's no way to know without pulling the head. Once you have done that, you have to put it back. Guess what? You just replaced the head. Whether you do it with a new one or the old one, it's the same either way.

tech

You can still buy a new head for these 4.0L engines , I did it the cheap way but I am a mechanic and do work on cars for a living so I do have all the tools to check the head .

n_co

Thanks for all the info!

I think im gonna go with a new head. I’m guessing I have the original head as I don’t see any casting through the oil cap.
Anything I should look out for or any brand recommendations?
Also, if I’m buying a new head any need for checking valves?

thanks again.

tech

I was looking at this company https://www.cylinder-heads.com/shop/...6275,6268,4152 https://www.cylinder-heads.com/produ...-2-02-ex-1-62/ at the heads they carry

tjwalker

How is your oil pressure? Have you had to add coolant to your antifreeze reservoir? If you have a cracked 0331 head, coolant will mix with oil. If not caught quickly it can and will toast your engine bearings. If caught soon enough, you can get a different head on there, change oil a couple of times in short order and hopefully be good to go.

Once an original 0331 cylinder head (the factory head for the 00-01) comes off, it should NOT go back on. Period. The factory defect between cylinders 3-4 is not something you want back on your 4.0, even if the problem was a head gasket....which it could be, but more often it is a cracked head.

Either source one from Clearwater Cylinder heads (link in above post from "tech") or source a salvage yard TUPY head where the factory 0331 head issue was resolved. Have head checked if you go TUPY.

Lots of threads on this to the original poster. Read up on this. You'll want a different head.

third coast

Have you had long term issues with overheating or loss of coolant? Been driven this way for many miles? If Yes to either you might pull an oil sample and have it analyzed. It will indicate if there is indeed antifreeze in the oil and if there is significant wear metals. It is nice to have a feel if the engine is in overall sound condition before spending a bunch of cost and effort in replacing a head only to find out later that the engine is at end of life. Significant antifreeze in the oil over time will cause excessive internal wear, especially on cam and bearings.