Finally dropped the oil pan on my 02 6 sp Max. The rod bearings were all scored and pitted. Found a lot of metal shavings in the pan but, surprisingly, the crank journal seems uneffected. The finish is still shiny and smooth. However, when turning the crank 4 of the 6 pistons have play. I can push them up and down with my fingers with no effort while the other 2 take effort and I hear the compression. Is that normal? I'm told because the car has been sitting for a couple of months the oil has drained which help the compression. Can anyone advise?

Thanks,


Bob

 

It is possible that the oil has sludged a bit but odds are the two you are pushing on have all the valves closed (which would mean you are trying to compress the air in the cylinders between the top of the piston and the head) while the other 4, at least two of the valves are open allowing the pistons to be moved freely as air escapes.

It has been years since I put together an engine but typically as long as the heads are either off the block or any of the valves are open, you can easily move the piston in the cylinder.

If you have a lot of metal shavings in the oil pan and rod bearings are scored, it is definitely time for a rebuild. Any particular symptoms that led you to drop the pan?

 

Yeah, the car crapped out on the highway and then I had rod knock. When you say rebuilt, then simply changing out the bearings and flushing out the engine won't do? Like I said the crank journal is not scored and if the piston are good (I won't know until I get it back together and do a compression test) I'm hoping that'll do the trick. And yeah, the oil did sludge quite a bit from the finely grounded metal.

Regards,


Bob

 

First, you need to determine the reason for the bearing failure - bad oil pump, bad oil, low oil, or whatever. Once you're satisfied that that issue is solved, then if new bearings is all you really need, then I see no reason to do any more than just replace them.

If your rod bearings are shot, then you'd better check your main bearings as well.

 

I changed my oil at 3k intervals and have never found it to be low. Bad oil, I'll never be able to tell. Oil pump looks good but I've no idea how to check? Can you advise? Also, with regards to the main bearings, not sure what these are. Can one see them from the oil pan? Pls forgive, this is the first time I'm venturing into these parts of the engine.

Any and all comments are welcome.

Regards,



Bob

 

The main bearings are very similar in form to the rod bearings, but they are in the main caps rather than the rods. The main caps/bearings are what hold the crankshaft in the engine block.

Given that you've never seen the inside of an engine before, I cannot recommend strongly enough that you get a knowledgeable, hands-on second opinion. Any advice other than that, given over the internet, is useless.

 

Mike the rod journals in the car or plastigage it, and make sure the crank's rod journals are still smooth and undamaged! Buy the appropriate rod bearings and install! You may as well do the main journals but you'll only be able to use the plastigage method after you carefully inspect them for any signs of damage! But the in car method can be done and if done carefully can provide yrs of extra duty! Good luck!

 

Odds are with metal shavings in the oil pan you might not have much choice but to rebuild the engine. There is a good possibility the cylinder walls have been scored and the oil pump has some damage. You need to find a good mechanic who is familiar with engine rebuilding to go through the engine to see what is damaged and what isn't. If you simply replace the rod bearings without making sure there is nothing wrong with the rest of the engine you will probably end up having to tear it down again pretty quickly.

You may get lucky and only have a few parts to replace, but then again, while you have the engine apart and can afford it, you can really make some nice upgrades internally that will give you more power and greater reliability.

 

You might try posting this in the "all motor" forum as well.

 

Yea just replacing the bearings without a complete teardown and inspection doesn't really make much sense. Spun bearings usually chew up the associated crank pin. Borrowed time my friend...