Cummins Engine ISX 475 , 920000miles, oil pressure 38psi at warm prior to changing the main and rod

Much of the older stuff you can get the timing cover off in the car. Trannys or bell housings can be unbolted and slid back. Automatics have inspection covers you can use to slide back converters and remove the flex plate. My logic was, if it can be done in a car or light truck it could be done in a big truck. I believe you if you say it can't.

 

I read this thread with interest. I am getting close to 900 k on my isx. I never saw a drop in the oil pressure. Typically it shows 35 - 36.5 on the scangauge when running, consums 1 gal of oil towards the end of 15 k interval. Should I still, at this mileage and no symptoms of any malfunction, replace the main bearings "just because they're due"? Or better not to mess with it to avoid problems like the one discussed in this thread?

 

Here is an ISX with 940k miles on it....no problems prior to ventilating it according to the owner.

 

I'm at 827,500 and starting to burn more oil. Will worn out bearings cause you to burn more oil?

 

Plastiguage.

Way too many lazy mechanics out there that don't want to properly spec the replacement bearings based on the tolerance in the bottom end after being measured.

I wouldn't doubt if they just got some bearings and threw them in, not even measuring anyting.

There is no way I would let this one go oil pressure dropping after doing a bottom end bearing job mean something was done wrong. Either the bearing tolerance was incorrect on the parts they installed or the pump got damaged during the procedure.


The oil pump is a whole separate issue, a shop reusing a oil pump with 900000 miles on it to me spells out incompetency and ignorance. Anyone with half a brain as a mechanic knows it doesn't make sense to put a pump back in with that many miles on it given the price of a new one is cheap. The risk is simply way too high.


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No.

Worn out piston rings will.


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Removed comment........

 

could you name some good shops/mechanics near chicago ? In need of getting some work done.

 

Theres a lot of things that can work fine before removal then fail right after being installed.
Good example I've had happen to me was when I replaced the water pump on my brother lexus is400, timing tensioner worked fine before removal but upon reinstallation failed. I tore the timing back off 3 times to make darn sure it was the tensioner that failed and not me just getting the timing wrong.
Its a weird thing that sometimes happens and in the repair world it can make customers think your ripping them off but really thats just not the case and at the same time you cant explain it.
But like a previous poster said when ever you do bearing checking oil clearence is utterly critical. Cheapest and quicket way is plasti gauge, you need the right type and you need to use it properly to get a reasonablely accurate reading.
Glad your oil problem was solved even though it cost you $1800 more, but it really might not be that shops fault.