Well, I pulled my oil pan today to see if my pickup screen was clogged because I just started having low oil pressure and I found a thin layer of shiny silver sludge in the bottom of the pan. Is this normal, or are my motor bearings shot? Truck only has 120k easy miles on it...and I would hate to think that Ford made a motor that would crap out after that many miles. It has been well maintained.

Thanks,
Hunter

1990 F250 Supercab 4X4 351 E4od

 

I dont know but that doesnt sound to good. Why just just replacethe bearings if you can while you have the pan off? I dont know if its a R&R part or not to be honest....never done one before.

 

i know that diesel oil turns to sludge when its contaminated, what weight of oil do u use it might be the same thing.

 

Sounds like bearing material.

Ford made millions of engines that crapped out before 120000 miles. (so did everyone else)

You can replace the mains and rods, and cross your fingers about the cam. That might help the oil pressure and keep it alive a while longer.

Good luck.

 

Can the main and rod bearings even be replaced with the engine in the truck, or would I need to pull the motor? This is the first time I have ever taken the oil pan off of a vehicle. BTW, there is no valve chatter or knocking yet.

rob: I have used 10w30 or 10w40 for the life of the truck, except for a couple of days ago I used 20w50 to see if it would help with the oil pressure...it didn't help.

As always, thanks for the advice.

Hunter

 

Without doing an oil analysis, you can tell if it is bearings by dropping a rod cap and main bearing cap. If you see scoring or brass, it's bearings.

 

Thanks bluesman, I'll try that first thing in the morning.

 

If you can (and you did) get the pan off, you can swap the bearings. Use standard size, (making sure the crank is std.) and inspect the crank surfaces.

If you have spun a bearing, all bets are off and you are looking at removing the crank for repair. In that case, it's time for an overhaul, as that amount of disassembly would pretty much open the engine up to the point where it would make no sense to button it up with old parts.

 

try dropping the rod and main bearing cap first see if theres scoring then we can go from there.

 

sounds just like main bearing. if you lost oil pressure and you see that in the bottom of the pan it can only be that. while your there thou you might as well replace the rod bearings as well. The crank is going to have to come out anyways.

 

someone correct me if im wrong once again but dont the rod caps and what not all have to be torqued to a certain spec.

ksubigbuck,
I'm sorry that I can't really answer your questions as my mech abilities are very limited when it comes to tearing down a engine. All I know is the bearings can be replaced while the oil pan is off and im pretty certain the rod caps have to be torqued down to a certain spec when reinstalling. GL man and I really hope that you dont have a spun bearing.

 

Last week I reassembled the lower end of my 351w. The rod caps were to be torqued to 40-45pounds, and the mains were 100-110.

I'm putting the top end back together this weekend, then pull my old motor and drop in my rebuilt, with headers, torque cam, etc. Can't wait to see the power difference.

 

First off, thank you all so much for the help...I'd be lost without you. I'll pay it foward when somebody asks a question that I actually know the answer to.

The rod bearing I checked had a little bit of scoring, but not too bad...probably best to just replace them while I'm in there.

The main bearing I checked was copper colored all the way around the bottom half of the bearing. Not really any scoring that I could see. Looks like it just plain wore out.

So, it looks like I'll be relacing both of those. Any tips for me since I have no idea what I'm doing? When I remove the main bearings and damper will the whole rotating assembly just come out? Will the pistons come out with it? If so, wouldn't it be a good idea to do the piston rings too?

Thanks again....and did I mention that you guys rock?

Hunter

 

Also, forgot to mention: the crank surfaces looked good in the two spots I checked.

 

The pistons will bottom out in the bores, never have been able to remove them from the bottom, but never tried either. You shouldnt have to worry about the rings unless you have scored the bore of the cylinders with a broken ring or bad piston. As for the Cam bearings, I would think you would be okay as most of the work load is transmitted to the crank bearings by the rods. A timing chain would be a good idea while you are in that far as well.