Spun crank bearing?

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GearheadTool

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Hello. I had originally seen a 1997 Subaru Legacy Outback for sale. The motor is junk. The description read:

I have available a 1997 Subaru Legacy Outback with a spun crank bearing and front body damage. Would like to sell whole car as is for parts or repair. Willing to part out if prices are right. $750 THIS WEEKEND ONLY, monday it goes back to $1000
^^ Obviously, i didnt buy it.

Post question: What does SPUN CRANK BEARING mean and Can it still run and drive Thank you.
 
^^ Ok just got back a text "Needs a motor."

Still. Lets talk about what a spun crank bearing is and means.

The seller also said the timing belt and tensioner were toast, so how does a thing like that happen
 
It doesnt mean it needs a motor but it means it needs internal work. The real question is why? That is likely not your only problem. Most of the time you ruin a main bearing from either neglect or over revving.

More than likely the 2.5L blew a head gasket, got coolant in the oil, and ruined one of the bearings. I would be willing to bet this thing actually does need an engine, but if not, it probably needs a comprehensive inspection and rebuild.
 
Originally Posted By: SLCraig
It doesnt mean it needs a motor but it means it needs internal work. The real question is why? That is likely not your only problem. Most of the time you ruin a main bearing from either neglect or over revving.

More than likely the 2.5L blew a head gasket, got coolant in the oil, and ruined one of the bearings. I would be willing to bet this thing actually does need an engine, but if not, it probably needs a comprehensive inspection and rebuild.


In other words, not worth it? I just exchanged texts with the seller.

By the way, the other guy has maybe decided to keep his Outback. I dont know yet. Got me interested in spun bearings, though. I knew someone with a Ford that had a spun bearing in the motor and they used real thick motor oil and drove it real gentle. It ran ok...
 
Bad stuff. Bearing shells have a small tab that's supposed to keep it from turning freely within the journal. For some reason it turned with the crank, either because it got severely worn and had way too much play, or it seized to the crank. At a minimum you might need the crank reground and use oversize bearings, but the prognosis is usually not good.
 
Originally Posted By: GearheadTool
^^ Ok just got back a text "Needs a motor."

Still. Lets talk about what a spun crank bearing is and means.


It means (in most cases) that it "needs a motor", and no it will not still run and drive.

Spun bearing means that the two halves of the shell have turned from where they should be, usually damaging both parts. Usually when someone says "crank bearing" they mean "main bearing" which would damage both the crankshaft and block. It could also mean "rod bearing" though which might be more repairable (resizing or replacing rod and crank, vs block and crank). At any rate, its going to be a costly repair if the diagnosis is correct.
 
This is old enough that you can find the engine in a boneyard. Usually a pull-it-yourself boneyard engine costs less than a single internal part such as piston, so economically this car needs a replacement motor.
 
Originally Posted By: GearheadTool
^^ Ok just got back a text "Needs a motor."

Still. Lets talk about what a spun crank bearing is and means.

The seller also said the timing belt and tensioner were toast, so how does a thing like that happen


The crankshaft spins inside bearing split shells that are retained in the block by bearing caps. Likewise, the connecting rods have split bearing shells held together by the rod cap, and the rod bearing rotates inside them.

The split bearing shells have tangs that hold them fixed under the caps that retain them either to the block or the rod, which keeps the oil feed holes in the bearing shells lined up with the casting. If a bearing begins to seize to the crank, the tangs can get sheared off and the bearing starts to rotate in the cap, which closes off the oil feed hole and hastens the seizing. Once the bearing shell fuses to the crank, it "spins" in the cap, and by that point the crank, bearing, and even the engine block or connecting rod are severely damaged. The block can usually be repaired, but the process (line boring) is expensive. The crank may be cleaned up with machining if it hasn't gotten hot enough for the metallurgy to be affected. But that too is expensive.
 
Originally Posted By: djb
This is old enough that you can find the engine in a boneyard. Usually a pull-it-yourself boneyard engine costs less than a single internal part such as piston, so economically this car needs a replacement motor.



This. Good advice. Way cheaper than messing with an engine with a spun bearing.
 
Originally Posted By: Brons2
Originally Posted By: djb
This is old enough that you can find the engine in a boneyard. Usually a pull-it-yourself boneyard engine costs less than a single internal part such as piston, so economically this car needs a replacement motor.



This. Good advice. Way cheaper than messing with an engine with a spun bearing.


+2, get an engine from a salvage yard, using www.car-part.com, stick the engine in it, and call it a day.
 
Last edited:
Originally Posted By: hemitom
What happened with the $500 subie.


I will c/p the email:

I'm sorry man, but I'm having an issue with my current vehicle and must cancel. I
need to drive my Subaru for a few more days.

I will be in touch, but don't come up today.

Sent from my iPhone

On Sep 6, 2012, at 9:52 AM, [email protected] wrote:


Has he decided to keep the car? I still want it but I need to know if he has decided to keep it. Sure sounds like he might of from that mail.....

Quote:
+2, get an engine from a salvage yard, using www.car-part.com, stick the engine in it, and call it a day.


This would be one of those situations where I ask the backyard guy how much he wants to do it in a weekend. I know all about scrapyard motors.. If I could find someone to do it for.. ? ($300? Im sorry I dont know how much they'd want. Probably more than that...) - This is one of those times.

Backyard or bust, shop would want more than the OTHER Subie.
 
Usually a Spum main bearing wipes out the block where the bearing goes. Sometimes the block can be line bored and repaired but it's not an economical repair with this car. A used engine would be a better choice.
 
being a 1997 in the the northern part of the rust belt is the car with that poor of care worth spending any time or money on if it was free???. Man the body better be really good seeing as you can't start it and drive it to see what other problems may be there.
 
I knew a guy who towed his MG at highway speeds behind his RV and left it in gear. He spun all the bearings. They rotated some with the crankshaft and were now out of position. The guy was not stupid but did some dumb things, this included.
 
unless you want to get into this car for some good money dont bother. Boxer engines are different that an inline or V engine.
 
Unless the motor was taken out, torn down and inspected there might not be a sure way to know the crank bearings have spun. if the bearings really did spin, you would need a new/used motor
 
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