How many hours from a Diesel Engine?

[Anonymous-0]

I used to have the impression that diesel engines ran a lot more hours than gas before needing a rebuild. I don't know why I thought that unless it was from hearing stories of tractors with buku hours on them or over-the-road tractors with a million miles? I talked to my uncle who runs a foreign car repair, he's seen lots of diesel cars with less than 200,000 miles with too little compression to keep running. I was recently taken by buying a Ford 5000 with low compression. The tractor did not appear to be a high houred tractor, but the compression was 275 across the board. Mechanics were suprised it even started.
I see lots of tractors that have been overhauled with around 4-5000 hours on them, then I see a lot more with 7000+ still going.
What's up, how many hours should be expected from a diesel? More or less or the same as a gas engine?
I'm about to the point of paying for a compression test on any tractor I buy in the future.
What are your thoughts/experiences? Any diesel mechanics have any input?
James

 

[DKase]

If cared for properly, serviced properly with the proper load any modern diesel engine should last 8,000 hours without major repairs. Many diesel engines run 15,000 hours if the bearings were serviced near the 8,000 hour reading. If not properly cared for and serviced they can be trashed at 100 hours. Color or flavor makes NO difference.

 

[Anonymous-0]

You are suggesting the rings/compression will outlast the bearings?
Is the friction/wear of the rings any different than that of a gasser?
James

 

[Anonymous-0]

It isn't the hours so much as how it is maintained, operated, and duty.

Significant wear occurs with frequent starting and warm-up as opposed to continuous running. All things being equal, a long haul gas/diesel will outlast a stop & go daily driver by a wide margin.

This isn't a tractor engine but is a basic diesel engine, an EMD 20-645E7B, 4k hp, 200 - 900 rpm used as ship's propulsion engine, mfr's ovhl insp is 12k hrs. The same engine driving a generator @ 900 rpm is 18K hrs. Of course, that assumes recommended maintenance, oil analysis, loading parameters, etc.

Joe

 

[DJM75]

Diesel usually have more rings 4 or 5 I even seen one with 6 once so friction could be more but don"t forget that diesel lubricates all these parts better than gas. Also its easy to get by with a gas engine and low compression than a diesel.

 

[Anonymous-0]

From my experience the biggest issue with diesel engine life is liner and lowerblock bore cavitation not rings or bearings have seen several motors with this problem with 4-6k with very little wear on bearings etc. Not shure why this is not an issue ao gas engines. JIM

 

[Anonymous-0]

That reminds me of another question I've been going to ask. Does that radiator additive which is supposed to stop cavitation have to be renewed if I don't replace the antifreeze? How long is it good for?
James

 

[Anonymous-0]

The additive we used was added to the antifreeze every two years. Now a good antifreeze will have all that in it allready. A seperate water filter was installed years ago by the companies but are not needed anymore. Just buy a good brand of coolant and it is ready to go.

 

[Anonymous-0]

I buy and sell a lot of used tractors but I dont buy much over 7000 hrs because when i've finnished with it it'll be over 10'000 and hard to sell again .Dont get me wrong i have had em up to 15'000 and still been reasonably reliable and still have a couple of 9-10'000's now but they will have to finnish their days with me ?
A gas ,I only have 1 and thats 1 too many ?

 

[BasketCASE]

Case IH dealers sell bottles of coolant conditioner for tractors without water filters. You're supposed to use that every year or so to replenesh the additives in heavy duty antifreeze. A neighbor had a coolant sample analyzed from a newer combine, and it said his antifreeze needed that additive. He put some in, and at his next test, the af was fine. I guess what I'm saying is, it seems like the antifreeze in diesel engines is not "lifetime" antifreeze, it needs a boost from time to time.

 

[Anonymous-0]

So, you are saying you buy lots of tractors with up to 7000 hours? And then plan on running them to 8,9 or 10,000? What percentage of those go bad while you own them?
How do you know they are not already bad when you buy them? Do you test compression or just look at smoke and blowby etc?
James