1991 Explorer Lifter Collapse

[msimmer]

My '91 Explorer 4.0 VIN X w/263k appears to have a collapsed lifter. Rather than pull the heads and replace the faulty lifter, is it possible to install a longer pushrod on the collapsed lifter to take out the slack? Seems like a reasonable solution but probably is not the thing to do.

Will also be replacing the rockers, rocker shafts and other pushrods. Despise the prospect of taking off the heads because I know I'll end up doing a whole top end rebuild.

[exploded99]

Originally Posted by msimmer

My '91 Explorer 4.0 VIN X w/263k appears to have a collapsed lifter. Rather than pull the heads and replace the faulty lifter, is it possible to install a longer pushrod on the collapsed lifter to take out the slack? Seems like a reasonable solution but probably is not the thing to do.

Will also be replacing the rockers, rocker shafts and other pushrods. Despise the prospect of taking off the heads because I know I'll end up doing a whole top end rebuild.

No shortcuts here. The pushrods are hollow and oil is actually pumped up thru them to lube the valve train. Collapsed lifter = no oil to that rocker. You would ruin that part of the rocker arm pretty quick. That may have already happened to your existing rocker arm.

Given you have 263k you might want to price an engine at the junkyard. Top end rebuild would actually take longer than a swap. I don't think the price of a used engine will be much more than all the new parts you mentioned. They will let you hear it run usually before you buy it.

[msimmer]

Thanks! Understanding that 1991 engines were prone to soft rockers and pushrods, should I replace with a newer year engine? If so, what are the pitfalls?

Originally Posted by exploded99

No shortcuts here. The pushrods are hollow and oil is actually pumped up thru them to lube the valve train. Collapsed lifter = no oil to that rocker. You would ruin that part of the rocker arm pretty quick. That may have already happened to your existing rocker arm.

Given you have 263k you might want to price an engine at the junkyard. Top end rebuild would actually take longer than a swap. I don't think the price of a used engine will be much more than all the new parts you mentioned. They will let you hear it run usually before you buy it.

[exploded99]

Originally Posted by msimmer

Thanks! Understanding that 1991 engines were prone to soft rockers and pushrods, should I replace with a newer year engine? If so, what are the pitfalls?

You know, I am not all that knowledgable on the first gens. I am thinking that you can use any 4.0 ohv, but you would have to use your current electronics on it. You would also have to swap your existing exhaust manifolds on it I suppose.

But, I think I will suggest you pose the same question at explorerforum.com. There are a bunch of gearheads over there that should know the exact answer to your question.

Lots of explorer rollovers out there. Never try to dodge a squirrel with an explorer. Should be plenty of engines to pick from. Might even get a package deal on an engine tranny combo if your ex is worth saving for another 100k.