douglee25
Well-Known Member
I agree with the above. Over fueling or hydraulicing the cylinder is only damage I'm aware of with a faulty injector. If it's truly not firing because it's clogged, you'd definitely notice immediately.
MAN diesel experience?
- Thread starter SeaNile
- Start date
- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
My experience with diesels is that routine checking of the injectors includes a pop test to analyze the spray pattern. If an injector is dumping excess fuel in a single cylinder you almost always know it from smoke in the exhaust at idle, raw fuel odor from the exhaust or a ragged idle. Injectors should atomize the fuel not spray it into the cylinder on top of a hot piston. Spraying fuel usually causes droplets of fuel (instead of a mist) to enter the cylinder and wash the lubricating oil off the piston skirt which will wear the cylinder liner quickly. Engines that idle a lot tend to accumulate carbon build up's and are more subject to bad spray patterns than engines that run at power producing rpms regularly.
I don't have a lot of experience with MAN's but their service recommendations seem to be directed are avoiding future problems rather than seling parts. Replacing injectors rather than testing and rebuilding them does seem like overkill, but is is one sure way to eliminate the risk of damage and a top end rebuild from a washed out cylinder.
lawndoctor
Active Member
- Jun 5, 2008
- 655
- Boat Info
- 2014 Princess 56 Fly & 2002 Sea Ray 225 Weekender
- Engines
- MAN R6 800s & Bravo III 5.0L
Someone suggested to me that the reason the MAN prescribed service schedule reads as it does is because in certain places it was incorrectly translated from the original German version into English, with the translation reading “replace” when it should read something to the effect of “check” for some items. I haven’t obtained the German version of the maintenance schedule for my 2014 R6 800 engines, but at some point I will try to get it and test the theory.
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SeaNile
Well-Known Member
What I am trying to understand is why does MAN recommend checking/testing injectors every 2 years and other manufacturers do not mention this?
Yeah, not obvious, but... German makers -- any manufacturing field -- are sorta well known for mandatory checks, mandatory service, etc. ... or that warranty goes south.
(Speaking of warranties, since the engines you're looking at are out of warranty anyway... so MAN wouldn't have to pay to rebuild if something fails, maybe -- in an odd sorta way -- that's yet another reason to not worry too much about it.)
I know you've spoken with dealers. Have you tried to ask MAN direct?
And how many over-the-road truckers have experience with these? Are there forums for that? Maybe their experience might turn up some useful factoids to.\o.
Anyway, we lived in Germany for a while. One night at the local Gasthaus one of our friends ordered some kind of dessert "ohne Sahna" (without cream) -- but the Gasthaus refused to serve it that way. Can't be done, wouldn't be "correct." We weren't actually all that surprised...
-Chris
(Speaking of warranties, since the engines you're looking at are out of warranty anyway... so MAN wouldn't have to pay to rebuild if something fails, maybe -- in an odd sorta way -- that's yet another reason to not worry too much about it.)
I know you've spoken with dealers. Have you tried to ask MAN direct?
And how many over-the-road truckers have experience with these? Are there forums for that? Maybe their experience might turn up some useful factoids to.\o.
Anyway, we lived in Germany for a while. One night at the local Gasthaus one of our friends ordered some kind of dessert "ohne Sahna" (without cream) -- but the Gasthaus refused to serve it that way. Can't be done, wouldn't be "correct." We weren't actually all that surprised...
-Chris
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SeaNile
Well-Known Member
For me it all boils down to looking at a boat with no up to date service records. This means about 25k to get the engines up to date and fully serviced. Once that is done the service for the heat exchanger and after cooler can be extended to 3-4 years since the boat will be in fresh water. The coolants should be changed at the same interval as any other diesel and the only thing that has been a bit debatable is the testing of the injectors every two years.
Assuming injectors all test OK... how much that cost to have done?
How much that cost if you do the dismount/remount yourself?
-Chris
douglee25
Well-Known Member
Tons of diesel shops online flow test injectors for $15-$20/injector.
SeaNile
Well-Known Member
On to the next. No more d2876 le.....possibly looking at a boat with the newer R6 MAN. Quick search is most people really like the R6 engines. It's newer, more efficient and a common rail engine.
swaterhouse
Well-Known Member
Will be similar maintenance schedule as discussed before with the exception of the injectors, and should be a bit cheaper since it's inline single turbo.
SeaNile
Well-Known Member
Exactly what i found as well when I researched. Almost seems exactly like any other diesel maintenance schedule now that you remove the injector testing.
Dissimilar metals between block and head? I'm sure that has it's own set of issues. My guess is maintain gasket and make sure head is torqued appropriately often.
