Mtnman90

I have a 2000XJ (with 110k miles) that I've owned since it was new. I've been a hawk about the cooling system - Griffin radiator, hood vents, regular coolant changes, etc. It's never overheated before. Usually runs below 205.

All of this being said, it has the 0331 head. I'm OCD about checking the coolant level and I always get used oil analyses done to see if there was any coolant in my oil. I was recently given (yes, given) a refinished TUPY 0331 head.

Does it make sense to do the swap? Or would I be opening up a can of worms unnecessarily? One thing I'm worried about is putting a refinished head on my used engine. It's had piston slap for the last few years (pretty mild, always goes away after warm up), other than that it runs perfectly.

XJwonders

if u got money to get other parts, and usually get bored, u can go ahead and do it just for the peace of mind. If u want to wait, u can. I have a spare tupy head sitting on shelf just in case too.

madmanmarty

Wait

andrewmp6

I would save up to buy a stroker kit and a edelbrock head.Its not the cheapest option but i rather do it once,

XJmike0122

There were around 286,000+ XJ produced in 00-01. I still say the 0331 head crack is a bit over exaggerated. If your that OCD and have owned your XJ from day one throw that tupy head on a shelf and let us know when you really need it.

abodyjoe

if it aint broke don't fix it in my opinion.

El_Guapo

Leave it alone until you need to open it up for some reason. As mentioned above, the numbers just don't add up. When you look at the number produced vs the number of "it happened to me" stories, the odds are so remote that no bookie on Earth would carry it.

Jeep Driver

That's not OCD......that's ****.

extrashaky

The pure numbers are probably in favor of waiting, but if it were me, I would do the swap anyway. Having been through the 0331 head saga myself, I know that I wouldn't be able to have complete confidence in the engine until that piece of junk were off there.

I know this is not scientific, but it seems like things always break at the worst possible time when I really need the Jeep. Then I'm either under a lot of pressure to get it fixed, or I end up spending the money to have someone else do it. If I knew I had a potential problem, I would rather take care of it on my timetable rather than when I'm forced to do it. The anxiety level would be a lot lower that way.

extrashaky

Not really. The oil analysis tells you a lot about what's going on in the engine beyond just whether there is water in the oil. It's really cheap compared to the information you get. I get my oil tested from both my vehicles, and it's been really interesting to see how the metal and chemical content has changed in the oil over time as the engines break in and age.

abodyjoe

i don't know. he has owned it since new. put 110k on it and has taken really good care of it.. i'd drive it and not worry about it at all..

El_Guapo

^^^THIS^^^

Any time you open up an engine, gearbox or any other machine you are resetting the "failure clock" for that machine. If you were to look at a graph of when machines fail, it looks like a cross-section of a bathtub. The likelihood of failure increases at initial startup (infant mortality) and end of life cycle (natural death).

Every time that you open up and change components, you go right back to the initial startup mode. It is better to do your diagnostics (oil analysis, documenting coolant loss, crackle test the oil occasionally) and put the job off until it is needed rather than as a preventative measure.

That head will sit on the shelf almost infinitely without much in the way of degradation. Why risk it?

Nodrama43

My 2001 developed a head gasket leak. 0331 head was not cracked. While i had the head off doing the head gasket i fitted a refurbed tupy head, along with a plethora of other stuff. I only wanted to do it once so i also did the water pump, radiator, heater core thermostat, injector upgrade, hoses, belt and on and on. Now its good for the second 105k.

Cheddarnut

This is a great example of what everyone is saying. Wait until you have a reason to pull the head and then swap it. Throw that baby on the shelf and it will be ready when you need it.

Mtnman90

Thank you all for the input. This makes a lot of sense.

I recently got a CEL for pre-cat efficiency (or lack of efficiency) so maybe I should do it when I'm replacing the precats and have the intake and manifolds off. Then again, the "bathtub theory" mentioned above makes sense. Really don't want to mess up my engine.