jpluvr4life

I need info on 1998 4.0L I6 cylinder head. I have the 0630 casting that needs replacing. Having a difficult time finding a new one. Parts stores seem to think all 3 different heads are interchangeable. Is this true? I've read they have different exhaust ports. The only thing available new seems to be the 0331.

Basslicks

That's odd that you'd be finding "new" 0331 heads. AFAIK the TUPY heads replaced the 0331's. If you're finding a new 0331, it's most likely NOS. Search for TUPY heads for WJs and late model TJs.

Martlor13

I believe the clearwater is branded as 0331 as well.

Basslicks

So is it just branded as 0331 or is it a true 0331 cast?

salad

That's correct. The 0331 design is the same except for the coil rail and exhaust ports. Aside of course from the original factory run that was prone to cracking - resolved in aftermarket heads and original heads bearing the TUPY mark.





You might search for a used 0630, which came on 4.0Ls starting in 1996. You could also install the exhaust setup for a 2000 49-state model but that's probably more money and hassle than you want.

What's wrong with your 0630, anyway? Head problems are extremely rare with those.

Martlor13

I believe just branded.

jpluvr4life

It is believed to be cracked. I had previous posts about a cylinder 1 misfire and things. I ran water through it and the 44k etc, then ended up changing my valve springs about 6 months ago and things were good for a while. Now it's back to barely idling with a cylinder 3 & 1 misfire. I did have a shop compression and leak down test it back when it still had its original misfire and was told everything was good. It will be compression tested again but I am looking for a head ahead of time, hah. I seriously love and hate that red beast these days

the_big_h

Watch when swapping heads, some have a 1/8" NPT port near the back of the head for a coolant temperature sensor, some don't.

If you need the port, and the new head doesn't have it, you can drill a port for the sensor into the thermostat housing, and extend the wire to there. (Or you could risk drilling the new head, but I'd rather ruin a $20 thermostat housing than a $400 head).

Basslicks

More accurate reading at the thermostat housing anyway.

william mirra

i recently got a p0103 code on my 99 cherokee xj i didn't find a listing for that code general obd code list says maf sensor. it needs fixing. Any ideas out there?

cruiser54

MAP sensor maybe?

rcguymike

diesel?

rcguymike

'99XJ 4x4 242, '96 ZJ 5.2L 249 Questions on fuel tanks/skid plates.

So currently I have a ZJ skid plate mounted over my XJ fuel tank. According to some recent research(thanks Basslicks and cleenrob :-P), I learned that the '96 ZJ fuel pump appears to be the same part number, connecter, etc so a fuel tank swap should be as simple as disconnecting from ZJ and installing in XJ...right? I have new fuel tank straps for both vehicles. Can I install the XJ tank in the ZJ(prefer to keep it easily moveable for snow) using the XJ tank straps? The ZJ skid plate should still work on the XJ with the ZJ tank right? Will the fuel level gauge work properly in both vehicles as well?

Basslicks

*sigh*

1992 XJ 4.0
TB is clean
AIC is clean
TPS is new
MAP is new
Coil is new
Wires are less than a year old.
Distributor, cap, and rotor is new and converted to the HO style
Recently replaced the valve stem seals... plugs are still pretty cruddy from all the oil intrusion.
Brand new MOPAR FPR - holds pressure to the rail looooong after the jeep is turned off.
Cleaned the injectors probably about a year and a half ago.
Has a stant 195* t-stat, the factory fan setup in place, and the shrouds are all still there as well. Cooling system has been given the Amway flush recently.

So here's the problem: I can go out to it after it's been sitting overnight or for at least 30-60 minutes, start it up, it will idle and run fine and I can drive it anywhere I want. If I'm in a lot of stop and go traffic, drive-through lines, or it sits and idles a lot, it starts to run HORRIBLE. Starts missing, then backfiring, then no power, then won't even rev, then eventually dies. After a few starting cycles, I can get it to run again by blipping the throttle through the RPM ranges and then tromping on it until it pretty much redlines. It's acting similar to heat-soak, which I know is a late-model HO thing and not an early model HO thing. So this leads me to believe that maybe the crack going all the way around the manifold at above the collector might be heating things up and making the sensors fail. Or maybe heat-soak?

To sum up, anyone know if a cracked-through exhaust manifold will cause the motor to backfire, run like crap, and just not drive in general?

My suspicion is the manifold, but I wanna know for sure before I pull the trigger on it and it's not the problem.

Anthony S.

I'm getting weak heat/air flow on my 01 GCL. I've replaced the blend doors,sealed up the hole that I cut.and now I'm getting codes 52 and 56! easy fix? or sale my baby???