'00- '01 Jeep heads crack?

[Bonnewagon]

So my Son-in-law thinks his '01 Jeep head is cracked. He hasn't yet explained to me why he thinks so. But research indicates casting 0331 heads used on '00 and '01 models are doomed to crack between #3 and #4 cylinders. Lucky me- I have an '00. It is so bad a couple of companies are making better versions of that head. I just hope he quit driving it before the bearings and lifters were hurt. Anyone have to deal with this?

 

[TURNA]

V-8 heads are poop VERY VERY common problem

 

[TURNA]

Oh wait thats the 6 head?

never heard of that

I had a 2000 jeep 250k on the clock damm thing wouldnt die, then the transfer case front bearing exploded

 

[Turbolq4]

The late model 4.0 I6 has head trouble. They crack because the exhaust ports were made smaller and moved up in the head to help the catalytic converter light off faster. Essentially they created a restriction to drive egts up. Thankfully the old heads will bolt right on. Unthankfully they need different exhaust manifolds fir the previously described reasons and they also have to be drilled and tapped for an idler pulley.

 

[Bonnewagon]

That's terrific. I read that later heads are better but need coil mounting brackets. My own has 175k and had lots of cooling issues but so far not the head. I guess it will depend on if he parked it before any other damage occurred. I advised him drain the coolant and oil, then fill with cheap oil and run for a few minutes to see if he has good pressure. If so and no expensive noises then drain that and refill with good oil and plan on getting the head. If crummy pressure and/or noises then it's probably trashed. Then again I saved that Trans Am 400 last Summer and it runs strong now.

 

[olds307 and 403]

V-8 heads are poop VERY VERY common problem

I had my 5.9 magnum heads fail badly. It blew all the coolant out of the rad quickly. There is EQ heads for the Magnum V8, they flow way better than stock and are much thicker everywhere. It looks like Promaxx has a new I6 head. https://www.summitracing.com/parts/pmx-chr640n/ Claims 91 to 06 on one site and 87 to 06 on Summit but there are differences. Edelbrock's aluminum head is for 91-06 intake and 91 to 98 exhaust manifold or header.

 

[Bonnewagon]

That's for a bare head right? these guys too.
"Or use a later style Head ("TUPY"). 2002/2003 and up.


Aftermarket Head- Alabama Cylinder Heads (800-235-4323)- $510 includes shpg....Currently 75+ back-orders. New, thicker casting in weaker areas.


Clearwater Cylinder Heads (800-572-1963)- $455 includes core exchange & shpg. (in stock)) J&C Enterprises (800-266-5599)- $439 includes core exhange & shpg." These are complete with valves for $480- not bad. https://www.cylinder-heads.com/product/new-jeep-cherokee-laredo-4-0-0331-cylinder-head-complete/

 

[olds307 and 403]

No, supposed to be complete, $661 plus a $9.99 shipping charge.

 

[Bonnewagon]

i think the Jeep forum said Promaxx used to be Alabama Cylinder heads.

 

[Bonnewagon]

You are correct- they are assembled.