Piston replacement

[MrBClark]

Just a random thought. I believe my Jeep has piston slap when it's at a cold start. I'm not really worried unless it gets worse. It goes away quickly. Its either a lifter or slight piston slap. Neither worry me too bad. I had posted a video of it a while back. Yall said it's fine and not to worry. Anyway, would it hurt anything to put in 6 new standard sized pistons and rings if it did get pretty bad? If it did come to that, should I also roll in some new main and rod bearings? I plan on dropping the oil pan when I change my pre cats in a few months just to check it out.

 

[Flivver250]

IMHO, if you are going to replace pistons, either you should rebuild the entire engine or install a re-manufactured long block with a warranty. A piecemeal approach to major internal engine component replacement is an inefficient labor plan. A good kit to totally rebuild an engine is not expensive. If you are going to open it up, wouldn't it be nice to not have to do it again for another 250K? Do it once and do it right.

 

[MrBClark]

IMHO, if you are going to replace pistons, either you should rebuild the entire engine or install a re-manufactured long block with a warranty. A piecemeal approach to major internal engine component replacement is an inefficient labor plan. A good kit to totally rebuild an engine is not expensive. If you are going to open it up, wouldn't it be nice to not have to do it again for another 250K? Do it once and do it right.

I would love to rebuild this motor (a stroker would be amazing), but this Jeep is my daily and I would be on a budget. I'm talking like a quick 3 day job with some help. I would plan on pulling apart everything. Hone all cylinders and measure all clearances. Reinstall new pistons, piston rings, and bearings after cleaning and checking over the crank. This Jeep runs great, if only I could get rid of the cold start noise. Even now, like I said, I am not alarmed too badly by it. I'm just saying IF it came to it, would this be an ok fix? I plan on dropping the oil pan in a few months just to be sure nothing looks horrible.

 

[Chris]

IMHO, if you are going to replace pistons, either you should rebuild the entire engine or install a re-manufactured long block with a warranty.

I agree with this.

New pistons means new piston rings, which means honing the block, which means you should be replacing the rod bearings ideally, crankshaft bearings, etc.

I wouldn't bother doing it unless I was going to do the whole block personally.

 

[MrBClark]

I agree with this.

New pistons means new piston rings, which means honing the block, which means you should be replacing the rod bearings ideally, crankshaft bearings, etc.

I wouldn't bother doing it unless I was going to do the whole block personally.

I agree with that too, but I do not have the time or money for that (I mean I guess I may but I'd much rather not). If I were to go ahead and replace the pistons, I would do the following as well.

Hone the cylinders, measure all clearances (including bearing size), check the crank for wear, replace the rod and main bearings, replace oil pump, new wrist pins, new pistons and rings, and new gasgets. Probably forgetting something but that is what I would replace that I can think of right now. Would this be more helpful than nothing?

 

[T_Hase89]

Why not find a high mileage long block for sale used, rebuilt as time / money allows and when yours lets go, pull it out, put in new. Same amount of work and cost (minus block) and less down time

 

[MrBClark]

Why not find a high mileage long block for sale used, rebuilt as time / money allows and when yours lets go, pull it out, put in new. Same amount of work and cost (minus block) and less down time

I actually thought about that. All I need is the block since the head is like new. Just had a tough time finding a block for cheap. It wouldnt even need to be in great shape. If I find a cheap block (or even engine), that is a possibility.

 

[Nimbley]

The problem with piston slap is it’s not the pistons. The bore is worn and it requires a minimum of .010” bore over and oversized pistons and rings to fix. New pistons and rings might mask the problem for a short time but it’s still there. All rebuilds need to have the cylinders bored and honed. You can’t just buy a used block and slap new parts in it. The block, crankshaft, and rods will need to go to the machine shop and you’ll have to buy pistons and bearings to match.

 

[Goatman]

Either do it right or don't do it at all. If money is tight (I get it) then don't start f*ing with the engine. If your not sure if it even is slap why do something that could possibly do more harm? Save your pennies and then do it right. You don't know what bearings you would need. Are they oversized? Just some of them? Does the crank need to be ground down a bit? All these questions can't be answered until you are in the engine. And then it'll be too late to do anything about it. Put your cats on and when you are ready deal with the engine. Never open a can of worms unless you are going fishing.

 

[MrBClark]

Either do it right or don't do it at all. If money is tight (I get it) then don't start f*ing with the engine. If your not sure if it even is slap why do something that could possibly do more harm? Save your pennies and then do it right. You don't know what bearings you would need. Are they oversized? Just some of them? Does the crank need to be ground down a bit? All these questions can't be answered until you are in the engine. And then it'll be too late to do anything about it. Put your cats on and when you are ready deal with the engine. Never open a can of worms unless you are going fishing.

I was just a thought. No, I does not need it and probably wont. Just a thought of something far down the line (if at all). Plus, when I do the cats, I will be dropping the oil pan just to check. Not fool with anything. Probably check the bottoms of the pistons and plastigauge the bearing just to check stuff.

 

[Goatman]

Do not disturb the bearings unless you plan to change them out. You will never ever get everything in the exact dead-nuts on position again. And then the wear pattern in the bearing half and the wear pattern in the crank (or rod) won't be in alignment anymore causing a much faster wear rate in the bearing. If you have no actual reason to pull the oil pan then leave it alone.

 

[Buckeyebutch]

If you aren't going to take the time to fix it right the 1st. time
How are you going to find time to do it properly the 2nd, time.

 

[mightymouse44]

If you aren't going to take the time to fix it right the 1st. time
How are you going to find time to do it properly the 2nd, time.

If you want it done nice do it twice