Bearing roll on acert?

I know a guy with a fleet of heavy haul trucks with nxs acert's in them and he had one spin a bearing after 600,000 the other upper rod brgs showed copper. In my option it all depends on application and load percentage. But as stated earlyier if you are unsure it's deffinatly cheap insurance compared to the cost of crank replacement.

 

If you get a bad oil sample have it checked again before you start buying stuff you don't need, I had a oil sample come back bad had it rechecked by the same place after I watched them clean their machine came back perfect.If your using an off-site lab ask them to return your samples when you send them in,that way you can have the same sample rechecked(checking freshly changed oil will not give you accurate information).By the way my '05 BSX ACERT C-15 has over 1,000,000 on the factory bearings.

 

I knew a guy that spun a bearing too, he used cheap oil and kept extending his change intervals.

 

I do heavy work with my truck and spun a rod bearing at 950,000 miles. I changed the oil at 15,000 mile intervals and did periodic oil samples. My truck still had 60 lbs oil pressure under load and didn't even lose oil pressure when it spun.It started a light intermittant knock at a stop light.The noise was the piston kissing the cyl head because of the bearing being gone. All the other rod bearings showed significant wear. Needless to say the new engine will get oil samples done every oil change and get a bearing roll at 650,000 miles need it or not.

 

Ok, so you ignored your oil sampling then. Re read your post. You did periodic sampling, the other bearings showed wear. This should have shown up on the sample reports. We have seen engines spin bearings too, with the other bearings showing significant wear aswell. Most of the wear is scoring which is an indication of debris in the oil, poor oil quality, or improper engine operation, not bad bearings. We have also seen bearing failure happen on engines that have been worked on recently, like oil cooler reseals or something like that, and whoever worked on it let debris get into the oil galleries. If your in a heavy haul and your bearings are wooped that early, the rest of the engine isn't too far behind.

 

Maybe I wasn't clear. I take full responsibility for this. The rest of the engine was original but it was getting tired power wise. Obviously if I had done a sample recently I would gotten a report of bearing material and done a bearing roll. On the new engine I will be doing oil samples on every oil change!

 

Normal trucks under normal service would never need bearings done at 650k. Heavy haul or severe service conditions is a different ball game. (Go Giants!!!) If you are in heavy haul the best thing you can do is regular oil samples and go from there.

 

I had bearings rolled in at 984K. Turned out to be a complete waste of money as the engine had to be overhauled at 1,125,000 At the time it seemed like a good idea. My oil pressure had gradually dropped about 5-8 psi depending on load and conditions. For example it used to run at 65 psi idling at 1,000 rpms then got to where it would be at 58-60 psi, bumping it up to 1,100 would get it up to 63-65psi. New bearings got the oil pressure back up to 65-70psi. The old bearings had nothing abnormal for the miles they had and could have been left in there for much longer is what I was told. My oil pressure was still in spec with the old bearings. With hindsight and an overhaul behind me it was a waste of money. My truck is not heavy haul and doesn't see extreme duty - just run of the mill ordinary freight less than 80K gross. One thing I almost forgot that another post reminded me of, my oil pressure dropped off after testing out Shell Rotella T-6 synthetic blend one time. I went back to regular 15W40 but the oil pressure was never the same after that little test. I blamed the oil for causing the drop and making me think I ought to roll bearings in. Maybe it was or wasn't I don't know...

 

Engines will loose a few lbs of oil pressure over their life, we all know this and it is perfectly normal. As long as the pressure is still nicely above minimum spec, doing a bearing roll to expect to get that pressure back is silly. Oil pressure loss is also due to worn oil pumps, cam bearings, rockers and shafts, turbo bushings and so on.

 

When ever I do a bearing roll-in I always buy a new oil preasure regulator spring, and I check the pump. I believe in doing the bearings often, If your engine warrenty is 700,000 miles I would do them at 350,000 and 650,000 looking for things covered under warrenty. The job is cheap insurance.