951C engine knock

[JCall]

Hi all,

I have a 951C (SN 86J4874) that I use on my farm. Recently it stalled while pushing brush. Would not immediately restart and there was a bit of a burning smell (like a fan belt maybe). I let it sit for a few days, restarted it this morning (cold out, about 34 degrees), it started hard, but started. It has a noticeable knock/miss and again smelled of burning after running only about 30 seconds or so.
I'm really looking for a mobile diesel mechanic to come out and look at it. Does anyone know of someone in the Winchester Virginia area? There is a Cat dealer nearby, but they are a little pricey. It has a Cat 3304 motor.

Thanks

 

[Dave Neubert]

Sounds like a spun main bearing motor will would have to come out when you say it starts hard do you mean the starter turns it over but labors?

 

[JCall]

Thanks Dave,

Not what I wanted to hear, but it is what I was expecting. To answer your question; when it first happened, the starter would not turn over the engine after it stalled (when engine was hot). After sitting for a few days, it would turn over and started, but took somewhat longer than normal to start and ran rough. I ran it for about 30 seconds before I shut it down as it was obvious that there was a serious problem.
So it will at least start, so I could probably for example, raise the lift arms if that makes engine access/removal easier. It would be great if I could find a lift arm support bracket as I don't have one.
The worse that I have ever had before was the top broken off of a piston on a 6V53 Detroit. This was serious but not catastrophic. I was hoping to eliminate the serious but not catastrophic before removing the engine.
Removing/replacing an engine is within my capabilities. Rebuilding one is not. Spending $10,000 for a rebuild engine doesn't make a lot of sense for a machine that's probably worth $8000 (at least that's what I paid 4 years ago). However, I like the old girl, so any suggestions for a machine that gets used less that a 100 hours a year would be appreciated (for example, thoughts on a used engine, resources, etc.). I just retired this year, so I have more time than money and unlike a contractor, I don't have to have the machine running right away (downtime is not an issue).
Also, am I correct in my understanding that a spun main bearing would require a new crankshaft in addition to a rebuild kit? New cam bearings as well?

Thanks again for the reply.

 

[56wrench]

I agree with the engine having to come out. I would cut apart the oil filter first though and see what kind of debris is in it. After the engine is out I would pull the oil pan and do an assessment of the bottom-end to see how bad things are. If you are really lucky, maybe only a rod bearing spun and the block is ok. Have you had any engine tear-down experience? The 3304 is a fairly simple engine to work on. How many hours were on the engine before this problem occurred?

 

[JCall]

The number of hours on the engine since a previous rebuild is unknown. I've had the machine 4 years. The motor ran strong with little or no smoke or oil consumption . The only known issue was that if I ran it for awhile and then when it was shut it down, it would restart fine, but if I let it set for twenty minutes or so, it (sometimes?) would not restart until I let it set for an additional half hour or so. I forget what the Cat service guy said about that when they serviced it. I think it might have been that it might need work on the injector pump (?) in the future.
I do have some tear-down experience. So, I think the plan will be as you suggest, check oil filter, remove engine and inspect bottom end.
I really appreciate the help so far and will report back results, but I have several other projects that are a priority, so it will probably be several weeks to a month before I report back.

Thanks again for the help.

 

[Dave Neubert]

If a main bearing is spun then you would have to have the block line bored to repair the block area a engine should not be to hard to find I would thiink you could repair it for less than that