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First, thanks for any and all help on this issue.
I recently picked up this 2000 cherokee with the straight 6 4.0. it had a intake manifold leak which i hear is common on these engines. it was idling rough. so before today it was running ok but just rough idle. Today i replaced the intake / exhaust manifold gasket (they share the same gasket on this engine). at the same time i replaced the valve cover gasket to fix an oil leak. So when all was said and done, when i fired it up, without my foot on the gas..it starts up but its like someone had their foot on the gas to the floor…the engine immediately races, like to the point where it would redline. i immediately shut it off ..checked to make sure the throttle wasn’t stuck open or something…but it wasn’t. tried it again, same result. i thought when i was doing it i put the gasket on right (felpro), it has locating pins..but it looks like it can go on two ways. It can go on either with some felpro writing out or towards the block. i put it on with the writing out. i did not have the torque specifications so i just tightened down pretty good. Even if i had the specifications, i don’t think there would be any way in hades to get a torque wrench on half of those bolts. Anyone who did this job on this motor knows what i am talking about. could the racing be to anything else besides this gasket? i took pictures before i started and am 99% sure i got everything back the way it should be. one last thing, the gasket that was on there was metal and the felpro was not metal but looked like some composite type (grey) gasket. Any help would be appreciated. I gave up for today, need to think it thru.
Thanks.
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ok, after looking over on some jeep forums, it appears that it is a common issue with these jeeps after this job. It looks like maybe the manifold is not located properly. i will have to pull the exhaust and intake off again. So now my question is, does it matter which way the felpro gasket goes on, with the writing out or towards the block. there were no instructions in the box. i want to do this right the second time. lol.
see if this helps.
OEM gaskets used that metallic type, but FelPro went with a composite they felt would work better. I know what you mean about the challenges to get in there, and dealing with both manifolds at once can be awful. What I do is take 4 bolts of the same thread size and cut the heads off. Use a hacksaw or a cutoff wheel and cut a slot in the top. Put those studs in to hang the gasket off of. Sometimes a small amount of weatherstrip adhesive rubbed with your finger until tacky helps on the intake gasket surface to keep it sticking in place to the block. Don’t use it on the exhaust side, it will just burn off. Those studs will hold up the manifolds and allow you to get your bolts in place. The slot is for a screwdriver if you happen to need it to get the studs out. You would want to gently snug a few bolts first before you remove them to keep everything from moving.
Torque specs don’t seem as critical here, and not easily done to get the torque wrench in anyhow, but do be sure to follow the proper sequence. Should be able to get it seated up properly then.
well i tried it again last night by loosing all the bolts and wiggling it in place and it seemed to seat much better and the holes (3) lined up on the power steering pump just fine. I tightened it all back up, confident that i had it this time…but then when i started it up ..it again immediately went to redline. Well gonna take it all off again tonight…gonna inspect the manifold for cracks. I hope i didn’t crack it with my first attempt. i also ordered the Mopar OEM gasket last night from rockauto. i hope 3 rd time is the charm…i will keep you updated.
To tell if the racing is from the gasket/vacuum leak. Try spraying carb spray to see if
the idle comes down. If it does gasket or crack. If no response you could have an idle
issue.http://www.ericthecarguy.com/faq/solving-automotive-performance-issues?start=3#CheckforVacuumLeaks
well, i removed the intake and exhaust manifolds again tonight…and took off the new gasket and upon examination, it looks like the new gasket is toasted. there was a tear and some separation of layers of the gasket. I think what happened was that when i first put it on and didn’t have the intake seated right, when i started it up it was too much pressure in that area and caused it to fail. I will know for sure if my theory is right when my new gasket comes hopefully tomorrow from rock auto, a Mopar gasket this time. I am sure the Felpro would have been fine if i did it right the first time.
Having a confirmed damaged gasket helps narrow it down a bit. Hope things go smoother on the next go around.
OK 4th time was the charm. Ibputbon the Mopar metal gasket and now idles perfect. Thanks everyone for your help. In case anyone runs into this same situation…on the Mopar gasket the stamped numbers should face out towards the exhaust/intake manifolds.
Great job sticking with it and getting it right! Just for the record, I don’t like that whole gasket/manifold deal there, it’s really my only complaint about the four point slow. I’ve done many 4.0 head gasket jobs and now I just get a hoist or a helper and pull the head with the manifolds and remove/install the manifolds while the assembly is off the car if need be.
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