50k miles crankshaft was grinded?

[Marcin]

Hi all

My friend SOHC 4.0 Explorer has oli consumption problem. At the mechanics they told him cramkshaft main bearings and connection rod bearings need to be replaced . Car mileage is 50k miles. When they changed bearings they told that crankshaft was already grinded before that repair. It seems to be strange for such a small mileage. There is no carfax information about it.
What it be possible that oversized bearings was used in factory? Or maybe there is any known problem of that engines with crankshat and its bearings?

Regards, Marcin

 

[SoNic67]

Maybe it does not have the original dashbord? What is the manufacture year?

 

[waskly]

only thing that will wipe crank/conn rod bearing is running with out oil. which brings up maybe the crank then has to be grinded to fit oversize bearings. or it could be that whacked that it cant be. shouldn't matter much since a new crank should come with matching bearings.

also what was the cause behind the oil consumption.

 

[Marcin]

The year is 1999. I am sure that mileage is 50k miles. The question is if it would be possible that engine was mounted in factory with oversized bearings.

 

[snoranger]

The year is 1999. I am sure that mileage is 50k miles. The question is if it would be possible that engine was mounted in factory with oversized bearings.

No the factory will not repair an engine. They throw it away and replace it.

 

[jd944]

It didn't come from the factory like that however it may have been repaired by a dealer or the previous owner.

 

[janolsson]

I had a sohc engine with oil pressure problems due to timing chain guides disintigrating and blocking oilways and bits getting into the oil pump.
At 90K miles with the oil pessure at zero at idle the main bearing were perfect but the big end(con rod) bearings were very worn.

I rebuilt another sohc engine with oil pressure problems for a short period of time and i found both the big end and crank bearings were well within spec.

I have read that the main bearings rarely get destroyed in these engines but the big end can be prone to excessive wear from oil starvation and my experience bears this out. Now if the engine is constantly starved of oil the of course the main bearings can get cooked and destroyed. if this happens then best option would be find a forum member that had junked their engine for timing chain failure and do a deal on their crank and use new main bearings (standard size). The engine will have to be pulled to do this job.