4.0 Manifold diaries: leaking, warping, skimming
04-26-2017, 08:59 AM
#1
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Year: 2000
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Engine: 4.0
4.0 Manifold diaries: leaking, warping, skimming
Hi All,
So I recently completed a whole head job as there was an incessant ticking that was driving me mad.
Lifters was suspect no.1 but it turned out many of the valves were seated too deep, causing the top of the stem to clash with the spring and in turn pushing too hard on the lifters wearing them out.
Well I replaced the lot, skimmed the head with new gaskets all round and a couple miles into the perfectly purring 4.0 a distinctive exhaust leak started ticking....
*there was no exhaust leak before the head job.
I took it to an exhaust specialist and they confirmed the leak was where the exhaust manifold met the cylinder head. It could be that either the gasket wasn't seated correctly OR that the manifold is warped (pretty certain its not a crack)...is this common? (The manifold was off the engine for 6 weeks, not sure ifthis would make a difference)
Unfortunately I do not reside in the US or any other country with the wide variety of aftermarket manifolds, so I'm going to try and salvage this situation.
If it is indeed a warped manifold, has anyone ever skimmed one? I'm assuming you'd have to do both intake and exhaust as they share bolts.
Any recommendations?
So I recently completed a whole head job as there was an incessant ticking that was driving me mad.
Lifters was suspect no.1 but it turned out many of the valves were seated too deep, causing the top of the stem to clash with the spring and in turn pushing too hard on the lifters wearing them out.
Well I replaced the lot, skimmed the head with new gaskets all round and a couple miles into the perfectly purring 4.0 a distinctive exhaust leak started ticking....
*there was no exhaust leak before the head job.I took it to an exhaust specialist and they confirmed the leak was where the exhaust manifold met the cylinder head. It could be that either the gasket wasn't seated correctly OR that the manifold is warped (pretty certain its not a crack)...is this common? (The manifold was off the engine for 6 weeks, not sure ifthis would make a difference)
Unfortunately I do not reside in the US or any other country with the wide variety of aftermarket manifolds, so I'm going to try and salvage this situation.
If it is indeed a warped manifold, has anyone ever skimmed one? I'm assuming you'd have to do both intake and exhaust as they share bolts.
Any recommendations?
04-26-2017, 01:28 PM
#2
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Year: 1996
Model: Cherokee
Engine: I6 Cyl / 4L
If it is the original manifold, it probably has a crack somewhere, or is about to crack. It's just a weak point in the design. No sense in trying to fix it - just replace with a new one.
The Jeep could also have developed a leak from the manifold gasket, but chances are if that happened it would affect the intake manifold too and the engine RPMs would go high.
But if the Jeep is running fine, you can do what a lot of other XJ owners do and ignore the ticking. This engine is a noise beast.
The Jeep could also have developed a leak from the manifold gasket, but chances are if that happened it would affect the intake manifold too and the engine RPMs would go high.
But if the Jeep is running fine, you can do what a lot of other XJ owners do and ignore the ticking. This engine is a noise beast.
04-26-2017, 04:48 PM
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Year: 2000
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I have to admit, im close to following the status quo, but I've spent so much time making this engine run well I can't give up now!
Ill have to take everything apart again anyway to confirm
the issue, but when the manifold was off there was no pitting, cracks or warping so it's pretty weird.
jusy want to find out if anyone has ever successfully skimmed a warped manifold?!!?? Anyone?
Ill have to take everything apart again anyway to confirm
the issue, but when the manifold was off there was no pitting, cracks or warping so it's pretty weird.
jusy want to find out if anyone has ever successfully skimmed a warped manifold?!!?? Anyone?
Last edited by RudeXJ; 04-26-2017 at 04:53 PM.