Trouble with a cummins 4bt

Brandon_M · Sep 3, 2016

Got a 1991 dresser td8g dozer with a cummins 4bt. Was working it the other day nothing hard just clearing a field. The 1st problem I noticed was a blown exhaust manifold gasket, pretty bad leak though. So I started toward the garage with it about 700 yards away. Started running rough, missing maybe. So I idled down & it completely died tired to crank it, it won't turn over. Looked engine over noticed the access panel for the push rods is knocked out away from the engine block, so I'm assuming bent push rods. Checked the oil no metal but way over full & is low on antifreeze. So I believe coolant is in the oil. I'm by far not a diesel mechanic, I can do the basics to keep them running. But I'm in trouble on this one. Engine was holding good oil pressure & wasn't running hot. Any help is appreciated, it's a great dozer way to good just to let it sit has been in my family since bought new. Thanks Brandon

Brodiesel · Sep 3, 2016

Interesting, those are great motors I wonder what happened. Tell me more? What are you going to do? I have built and installed 4 of those motors this year.

lantraxco · Sep 3, 2016

One possibility is a piston or wrist pin let go, piston stuffed the valves, rod end punched the liner. WAG.

Brandon_M · Sep 3, 2016

I walked down & stared at it again a few minutes ago. I stuck my fingers in the gap between the block & the access panel for the push rods & pulled out several pieces of metal. I believe it was pieces of the cylinder wall not for sure. Does this mean a new engine or is there sleeves in these motors

Brodiesel · Sep 3, 2016

You mean you stuck your finger in the whole between the two pushrods? If you felt metal there than for sure a rod bent and cracked the block open, I attached a photo of that same style block (B-Series) I keep in my office, as you can see the hole in the block is directly between/under the pushrod area. These motors do commonly get sleeved but usually just to restore cylinder diameter, not to replace large cracks and holes.

Delmer · Sep 3, 2016

No sleeves in a cummins B series. Was it running on three cylinders? Can you post a picture of the metal pieces, it should be pretty clear if they were part of the cylinder or rod. Then it's time to start looking for another engine.

Heavey Metal · Sep 3, 2016

Prolly the noise was a keeper on the way out

Than swallowed a valve

How often do you set the valves?

JS300 · Sep 3, 2016

This is probably a stupid question but could something like this happen from not changing or using the wrong antifreeze/coolant? Discussion came up at work a couple weeks ago about coolant going bad and causing cylinder wall pitting in diesels. Knowing a bunch of folks that never do any upkeep or maintenance on old tractors I just blew it off. I did decide to get a coolant test kit though just to see. My skid steer has a 4BT and it tested good dozer has a 6BT and it tested bad. I changed the coolant today. The test strip actually said "change immediately ". Like I said might be crazy but just got me thinking about when you hear of a perfectly good engine suddenly blowing up.

Brandon_M · Sep 3, 2016

These are the pieces that I pulled out from behind the push rod access cover.

Brandon_M · Sep 3, 2016

From behind this panel is where they came from. I could definitely feel a bent push rods as well. But that's the least of my worries now.

Brodiesel · Sep 3, 2016

Wow, definitely pieces of the block casting, 4th cylinder. You definitely will at least need a new shortblock. I would exchange it with a good runner with matching injection pump and HP. You might want to contact Chad Mckinney in Cincinnati, Ohio, seems like he's got at least 100 of these motors from all types of applications, he's helped me in the past. I would be interested in repairing it for you but I'm in California and the shipping could be a killer.

Brodiesel · Sep 3, 2016

You should get that pushrod cover off, I think 4 10mm bolts, then shimmy it out if theres not too much in the way.

Brodiesel · Sep 3, 2016

I don't think so, and the cylinder wall pitting usually happens with wet sleeve engines, but It's good that you did a test. I think the biggest problems with the B-Series mechanical engines is people just running em forever and never even checking the oil then one day-BAM!

Brandon_M · Sep 3, 2016

Thanks for the offer & help Brodiesel but shipping would be awful to Cali & back. I'll contact Chad next week after the holiday weekend I can drive to cinci in about 3 1/2 hr. Tomorrow I'll take the pushrod cover off & take another pic then post on here for you to look at. It's just odd to me this dozer never give no sign of anything going wrong.

Brodiesel · Sep 3, 2016

I feel ya, good luck, lets see how it goes....

Dickjr. · Sep 5, 2016

Look up ironpeddlers in London KY. Give them a call for either a running take out or they may have a remanufactured short block. How many hours were on it before it let loose? Was it making any noises? Some people like to run the b series down , you'll here of this often but when there are millions of these out there running your gonna here about the few. My D39 Komatsu has the same engine just modified by Komatsu a little . Just read the post over , it showed no sign of issues. It would be informative to tear it down and see what failed. Almost sounds like the oil pump.

Brandon_M · Sep 5, 2016

Thanks Dickjr, I'll sure look them up. No signs of it going down always ran great & good oil pressure. I haven't done anything to it yet until I get another engine that way if I have to transfer any parts I can do it right from one to another. But I'll for sure open it up to check it out some. I believe the dozer has 5300hrs. Not for sure right off the top of my head. I know it's a repower though but it was done when the dozer was less than a year old.

Brandon_M · Sep 5, 2016

I'm not so sure of the repower plant on this dozer now. I was confused between the cummins 4bt & the dresser d240t. This maybe the original engine. The dozer has been in my family since new but the 1st owner is no longer around to talk to about it. But anyways on the hunt for a reman 4bt turbo motor now. Thanks for everyone's help

John C. · Sep 5, 2016

I think the late model G machines had the Cummins and there were plenty of conversions done and the corn binder engines wore out of failed. The Cummins have individual valve covers while the International had a single valve cover.

Rod bolts were a weakness on the B series engines. It got to the point in those days of never reusing them when rebuilding an engine.

Brandon_M · Sep 5, 2016

Ok John C. I knew the engine had the appearance of a cummins. It does have the individual valve covers, but some had mentioned it being a dresser engine the D240T. I didn't know that these 2 engines was the same but just different names. But I have gotten everything cleared up now. Just waiting on the businesses to open up after the holiday to call about a replacement. That's gonna bite my wallet pretty hard. LOL

Trouble with a cummins 4bt

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