Bearing Wear - Copper Showing

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Don65Stang

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This is from my 5.0 engine...helping my son with the rebuild. I've rebuilt a few engines but I don't know how to tell what happened inside looking at the wear marks, etc. Car has 91k miles and the engine has never been apart - until now. The 5.0 has forged pistons & a roller cam.

We pulled it to replace the oil pump due to low oil pressure and do a general engine & bay cleaning/detail.

Pulled off the oil pan. Not all gunked up inside. All cylinder walls still had good visible cross hatch patterns. I decided to pull the rod and Main Bearing Caps just to inspect. I was very surprised to see really bad wear marks and copper!

So what do these wear patterns mean? Pics start at the First Main Bearing and work toward the rear.

Front (1st) Main Cap Bearing pics below...

IMG00626-20110402-1537.jpg


IMG00625-20110402-1537.jpg


1st & 5th Rod Cap Bearing...

IMG00624-20110402-1536.jpg


IMG00620-20110402-1534.jpg


2nd Main Cap Bearing pics below...

IMG00619-20110402-1534.jpg


IMG00618-20110402-1533.jpg


2nd & 6th Rod Cap Bearing...

IMG00617-20110402-1532.jpg


3rd Main Cap Bearing pics below...Note the wear marks on the side. Normal?

IMG00614-20110402-1531.jpg


IMG00613-20110402-1531.jpg


3rd & 7th Rod Cap Bearing...

IMG00611-20110402-1530.jpg


IMG00610-20110402-1530.jpg


4th Main Cap Bearing pics below...

IMG00609-20110402-1530.jpg


IMG00608-20110402-1530.jpg


4th & 8th Rod Cap Bearing...

IMG00607-20110402-1529.jpg


IMG00606-20110402-1529.jpg


Rear Main Cap Bearing pics below...

IMG00605-20110402-1529.jpg


IMG00604-20110402-1529.jpg


Here are a few pics of all of them side by side (except the Main Bearings that are still under the crank in the block). I tried to label them.

IMG00664-20110402-1909.jpg


IMG00665-20110402-1910.jpg


IMG00666-20110402-1910.jpg


IMG00667-20110402-1911.jpg


IMG00668-20110402-1911.jpg


Please help me figure out what is going on to cause these wear patterns. Thanks.

.

 
When you say low oil pressure, how low for how long? Have you had the car since new? Is the oil pump iron or aluminum? It looks like oil starvation to me. What do the crank surfaces look like?

Chuck

 
Or maybe a result from a dry start... if not primed properly, it takes a while for the oil to get from the oil pump to the rear bearings, which seem to be the ones showing the most damage.

Or maybe the oil pump wasn't working properly, which could also cause the bearings furthest from the oil pump to show with more damage.

This is my first rebuild, and I spent about 45 minutes today looking at my bearings and comparing them to photos in the Haynes Ford Engine Overhaul Manual.

Doc

 
When you say low oil pressure, how low for how long? Have you had the car since new? Is the oil pump iron or aluminum? It looks like oil starvation to me. What do the crank surfaces look like?

Chuck
Agree oil starvation. See this post I made about plastic shavings that were clogging the pickup screen. How long? I don't know. I was driving around hot-rodding it a little bit because it sounds great at 4k rpm with the current exhaust when I heard it making a ticking sound that varried with the rpm. Still had oil pressure at that point. So I started limping my way home about 5 miles away. About a mile into it the gauge dropped to zero oil pressure and that's when I shut it off and called the tow truck. I thought the oil pump or shaft went bad.

We pulled the engine to change out the pump and investigate for the source of the plastic shavings.

I've owned the car for the last 5 years...bought it with 62k original miles from a friend who only drove it during her HS & college years. It sat for several years undriven...had to rebuild the AOD due to her letting it sit for so long.

Crank surface looks clean & shiny. When I pulled the caps there was lots of oil between the journal and bearings.

 
The 90 5.0 I had for 18 years had an aluminum housing oil pump which siezed at 104K miles. Twisted the drive rod like a pretzel until it snapped, zero pressure.

Chuck

 
I thought the oil pump drive rod also and expected it find that as the problem but it was fine.

The BIG question now is how to fix it. Low budget is the key since my 17 year old is paying the bill...his car = his bill. Can we just turn the crank, get new oversized bearings, reassemble and go? Would the rods need to be reconditioned also?

 
Take the cover off of the pump to see how much scarring is present on the "gears". If it is trashed you still have to find out what the source of contamination was. If it is OK, I'd be surprised, you have to figure out where the pressure is bleeding of at and fix it (Oil galley plug, pump plug, etc.). If you are successful in this, turn/polish the crank,put in new main and rod bearings and a new STANDARD pressure pump, prime the oil system, and see what happens. The cam and lifters may be OK. All of this is assuming there were no ring sealing or valve sealing problems to begin with. I hope it goes well for you.

Chuck

 
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