Tymorin

I have a 2000 Grand Cherokee 4.0 I replaced the head not new but remanufactured now a lifter is blown and I'm having a misfire. I know I have to take off the head again to remove the lifters but my question is there a way to leave my intake and exhaust attached to the head and move the head a couple inches right? Would I need to remove the manifold from the bottom part of the exhaust? Also if I'm replacing my lifters and not my cam how bad is it really? Is the cam replacement alot bigger job then the lifters? Thanks in advance

dave1123

That "bumpstick" is as long as the engine and requires removing the entire grill and jacking the block high enough for the cam to clear the front frame. In the long run, it's easier to remove the entire engine from the vehicle. You can get away with putting new lifters on an old cam as long as the cam lobes are smooth and not rounded on the edges of the lobes. A good way to tell is to inspect the bottom of the lifters for "cupping." That is being concave and not flat. You should NEVER put in a new camshaft with old lifters. You can check the lobe lift with a dial indicator, should be 0.253" measured on the lifter body when turning it over.

The head can be removed with the manifolds installed but you'll need a engine crane. The head itself weighs around 78 lbs and the exhaust manifolds are cast iron. You have to disconnect the catalytic converters from the manifolds. Remember you must clean the head gasket surface before you put it back together. I suppose you could remove the manifolds AFTER removing the head from the jeep, then re-installing them before putting the head back on but remember there are 2 dowel pins the head aligns on and you can't slide it back into place or you'll ruin the gasket and scratch the head surface. There's at least 1 head bolt in the back that you can't remove from the head because of clearance with the cowl and it must be in the head before you put it back on. Be aware that the front head bolt near the exhaust manifold and thermostat housing only gets torqued to 100 lb/ft because it's the only bolt that's tapped into the water jacket and if torqued to the same as the others, could crack the block in that area. It also must be sealed with thread sealer or it will leak coolant. The head bolts should be replaced with new ones to be safe. The FSM says you can reuse them ONCE, but the bolt heads should be painted with white paint to show they are used.

If you do replace the cam, make sure you time the cam sensor drive gear properly.

97grand4.0

I think you can remove the head and intakes together without too much effort. If you can lift the head off by yourself you can do it. Have seen many others say they did just that.

third coast

Good info from dave1123. Note however that good condition lifters should be slightly convex (slightly bulging outward) on the surface that rides on the cam. If scratched, flat or concave they need to be replaced and there is a good chance the cam lobes are also damaged. It is a good idea to put some assembly lube on the convex surface when reassembling the lifters into the block.

Yes, the easiest way to remove the head is with manifolds attached. And from my experience having the manifolds attached to the head is about the only way to get all the manifold bolts properly torqued. The entire assembly is heavy so two people or a block and tackle arrangement or some other overhead lift approach is very helpful to carefully set it back on without damaging surfaces and head gasket. Hood can stay on as there is adequate clearance for an overhead lift arrangement.

Cleanliness for any of this type of work is important in helping to get a good outcome. Remove all old gasket material with a razor blade, not a wire wheel, and take precautions to prevent debris from getting into the engine and around tops of pistons.

third coast

Maybe a question we should ask is how sure are you that it is a lifter issue? Improperly tightened rocker? Broken valve spring or related issue? Valve not seating? What are the symptoms?

97grand4.0

[QUOTE=third coast;3551327]Maybe a question we should ask is how sure are you that it is a lifter issue?

Great question. Nothing like rebuilding and engine to find out the pcm injector driver went bad.

Tymorin

Thanks for all the info first off. Much appreciated i have taken the head off a couple times (ripped the gasket the first time I put the head on). I removed the exhaust and intake Everytime but had the hardest time putting them back on but wasn't confident taking it off from below the exhaust manifold and removing it. To answer the lifter question I did take off the valve cover and checked all the rockers where tight but the very last one I could easily push down with a finger. The last time I did the head I did check to make sure my rockers and pushrods where still straight. The jeep will run and drive but has a misfire and tick.

97grand4.0

Yeah if you can push the lifter down with a finger and not the others it sounds like a collapsed lifter. However if the valve train has a problem that could be what caused it.