Community Forums

n2zon · 11-24-2020, 04:35 AM

Unless the block was mis-machined, replacing the cylinder liner should solve the out-of-round problem. With the head, piston, and rod out of the way, they come out the top. It's hard to imagine getting 90K out of it if the block were machined so poorly that it caused the liner to be oval, and hard to imagine how the manufacturer could even have done that in the first place.

The crankshaft, connecting rods, and pistons should be able to come our from the bottom. These engines are often just rebuilt in place, still bolted in. I'd have a strong preference for doing that unless there were an irreparable problem with the block that required the block itself to be replaced.

Just another opinion. I'm neither in the shop with your coach, nor am I a diesel mechanic (but I'm learning!).

rabdnomaidx · 11-24-2020, 03:54 PM

When they removed the head they noticed the one cylinder wall as being worn badly.

rabdnomaidx · 11-24-2020, 03:58 PM

Thanks.
I was told that the machine work that needed done could not be done "in frame"
I certainly am not a diesel mechanic by any means. Just hope it all works out after all of this. Could have bought a replacement engine by now.

wolfe10 · 11-24-2020, 04:10 PM

There ARE aftermarket companies that bore and install a cylinder liner in Caterpillar 3126's WITHOUT REMOVING THE ENGINE.

I saw one being done at Mustang Caterpillar many years ago when I was there to get parts. Check with Caterpillar dealers in your area to see who does it.

Sure doesn't sound like you have a competent rebuilder to not check everything with the head and possibly the pan off. Discovering an out of round cylinder AFTER the engine is back together is truly negligent.

Fefanatic · 11-26-2020, 04:48 PM

Quote:

Originally Posted by wolfe10

There ARE aftermarket companies that bore and install a cylinder liner in Caterpillar 3126's WITHOUT REMOVING THE ENGINE.

I saw one being done at Mustang Caterpillar many years ago when I was there to get parts. Check with Caterpillar dealers in your area to see who does it.

Sure doesn't sound like you have a competent rebuilder to not check everything with the head and possibly the pan off. Discovering an out of round cylinder AFTER the engine is back together is truly negligent.

Yep, pulling the head and finding a badly worn/scored cylinder after the first repair doesn't give me any faith in the mechanic.

That being said if the engine is already torn down it should be a lot easier to finish the removal. If it were me I would be finding a shop that is more qualified to do the job. There's too much money involved to be gambling on a good outcome here.

Fefanatic · 11-26-2020, 04:51 PM

Quote:

Originally Posted by rabdnomaidx

Thanks.
I was told that the machine work that needed done could not be done "in frame"
I certainly am not a diesel mechanic by any means. Just hope it all works out after all of this. Could have bought a replacement engine by now.

That's the downside to not knowing the expertise of the shop. I'm not sure I would be putting any more bad money after good money with this shop.

Have you looked into a good low mileage used engine? I would rather do that than trust this shop to properly repair your existing engine.

Unplanned Tourist · 11-26-2020, 05:21 PM

It sounds like a piston cooling nozzel is plugged, and it cooked the cylinder.

90,000 miles and then it happened? Or was it after the cyl head change?

I was a HD truck mechanic for 40 years, and we had a boring bar set-up to bore blocks oversize when the liners were loose or cracked. I did a lot of engine rebuilds that required boring, and you have to know what you are doing, or you can end up with a botched job and a scrap engine block!

So that job was left to us older guys with experiance.

Petesflhtk · 11-26-2020, 05:34 PM

I thought the 3126 didnt have piston liners ?

sibe · 11-26-2020, 06:11 PM

Just texted a friend.. Young guy.A tech at a large cat shop.. They do off road equip to onan generators..

Cylinders are not re notable.. There are .020 piston but that's bandaide. Bore it for a sleeve is factory repair... Do it right pull it. Do them all.. Rarely they do one unless it was low hour factory oops..
He said they have portable boring bar. Torque plates and finish hone machines..

To him it was no go big deal but pricey.....anything at that shop is dollars. He gets paid more than my autoshop charges an hour.. Lol

Good luck
.

bpu699 · 11-26-2020, 06:34 PM

As an aside, I see school buses with cat 3126’s for sale on Craigslist for $3500, with 150,000mile motors...

Oddly, a used motor from a dismantler is often $8000.

Seems buying a school bus and transplanting the motor might be a cheap option...