Spun Bearing help

[keeferfish1]

Spun Bearing help

2001 SSEI with 100K

Bought the car about a month ago and they said it had the upper intake gasket replaced and they had the receipt.
I drove it about 2,000 miles car rides and drives great UNTIL:
Heard a load knocking – only drove a mile put it on the lift and the rod bearing on the far side (drivers side) had spun.
Everything else looked fine including main bearings and piston walls. Replaced all rod bearings ran great for about 50 miles and did the same thing, well I guess because I haven’t tore it apart yet?
One other note – right before it starts the oil pressure goes crazy and bounces around everywhere. Any advice?? I just like it to run and be a daily driver. We drive it like a grandma. Any help would be appreciated. Thanks

[bill buttermore]

The engine is gonna have to come out. The oil pan, cylinder head and all of the oil passages will need to be meticulously cleaned ~$50-$150. The oil pump on the front cover will need to be checked carefully for clearance and possible damage. The adapter plate will need to be disassembled, checked and cleaned. The lifters will need to be disassembled and cleaned. The oil strainer may need to be replaced. The connecting rods will need to be checked ~$50 - the rod with the spun bearing will probably need to be machined or replaced if necessary ~$30. The piston, valves and cylinder wall on the cylinder with the spun bearing will need to be carefully checked for damage. If all is okay, you can install a crank kit - reground crank with new matching main and rod bearings ~$200. Put it back together with all new gaskets and seals ~$250-$300 and you will be good to go. So....budget about $700 to fix it if you can do your own work.

[keeferfish1]

We can do our own repairs, luckily I have a friend with a lift, a lot of tools and knowledge (or I use to have a buddy). I may just want to fix and sell the car but don’t want to screw the next person. I want to fix it right. The car rides and drives great! Should I just replace with a used one?

What do you think caused the problem. There was a lot of sludge build up in the pan. Did it get sucked up into the sump? How would I know if it was a coolant problem? Oil pump problem – they only sell a rebuild kit for the oil pump.

Thanks again for the advice.

[bill buttermore]

(Moved this reply so the thread makes more sense.)

You can put new bearings on a good crankshaft, but once a bearing has spun, the damaged crank journal (and possibly the rod if it is also damaged) will quickly cause the new bearing insert to fail. The cleaning is needed because when a bearing fails, typically a host of small metal particles get circulated through the oiling system. You would think that the oil filter would catch them and prevent them from circulating, but that usually seems not to be the case. If you don't get all the debris out of the oiling system, it will be circulated to the new bearings and immediately damage them. The whole business takes a lot of time and careful work. It is not difficult, but if you have to pay a mechanic to do it, it will probably be less expensive to replace the engine with a good used one.

Preventive maintenance (replacing LIM gaskets before they fail) to minimize the possibility of internal coolant leaks is good insurance against the most common cause of bearing damage.

Sounds like #6 bearing spun. #6 is the bearing farthest from the oil pump. One bad habit that can increase the odds of spinning #6 is revving the engine immediately upon start up before oil under pressure has had a chance to make it to the bearings. Protection for the bearing during those first few hundred revolutions relies on whatever oil film remains between the bearing and the journal. If the oil is diluted with gasoline from a dripping injector, or doesn't have a very good film strength to begin with, bearings are at risk.

If you repair the engine, before you start it up, you will want to prime the oiling system by turning the engine over by hand with the plugs out until oil pressure is developed. That insures that a nice film of oil is present to protect those new bearings. I use a heavy electric drill with a 1/2" drive adapter and socket on the crank bolt to do this. Also, check the oil pressure with a mechanical gauge, and replace the oil sender if it does not agree. Electrical ground issues can also cause erratic gauge readings.

[Oldman]

Don't feel like the Lone Ranger dude!
I've seen the same thing happen on many others.
Any time I hear of one with a knock that sounds like a bearing "spun", that's the first question I ask. "Have you recently had the IM gasket replaced?" 90% of the time - I'm not exaggerating - they scratch their heads and say - "Yeah, how did you know that?"
I've come to the conclusion that when the IM gasket is replaced it's one of two things:
1. Either they aren't careful and have pieces of gasket or general "junk" get down into oil passages that eventually make it to the pan and cause problems.
2. They don't drain the radiator and block and when they remove the IM and they get collant in the oil and don't change the oil after replacing the gasket.

Again, I've only seen one of these that spun a bearing that wasn't within 6 months of having the IM gasket replaced and that one looked like it had gone 50,000 miles without an oil change and driven hard too!!

If it's a rod bearing that spun, I'd drop the crank and have it machined and closely inspected. I'd replace that one rod and check everything VERY CLOSELY for any foreigh matter.I'd force air through every oil passage you can get to and I'd replace the oil pump.
I'd replace the oil sending unit, so you have some confidence in the gauge and see how it goes.

Good luck dude!!

[bill buttermore]

Oldman, this is why we encourage our members to replace the lower intake manifold gaskets and (for the L36 engine) the upper intake manifold with improved designs before they fail - to head off contamination of the oil with coolant that occurs when either of those items begin to leak. Because most people do not replace the LIM gaskets or the UIM until they have failed, we have seen bearing failure, as you mentioned, a few thousand miles after those repairs are made. I would suggest that bearing failure occurs in these cases not so much because of sloppiness in the repair procedure, (although that can happen, too) but because the bearings were damaged prior to the repair when the oil was contaminated with coolant.

[Oldman]

That's great advice for folks.
I guess I've just never had one brought to me that spun a bearing that had not yet had the manifold gaskets replaced. When I've replaced the gaskets it's been because of a leak, running rough, or smoking or because it came in for an oil change and the contaminated oil was found.