MEP-803a constant exhaust haze and then total failure

[ksvik]

I've had an Mep-803a for a couple years. We live off grid and so it runs quite a bit, probably at least 1000hrs over that time.

It's always had an exhaust haze size i've owned it. Positive its not coolant as never have lost a drop. Pretty sure it's unburnt fuel haze. Replaced the injectors with aftermarket ones. Played around with the timing shims, even tried to disable fuel to individual cylinders but nothing seemed to make any difference. Always started up no problem, even in the cold without preheat. Never checked compression as seems no easy way to check without fabricating a custom injector. Eventually just lived with it but it did bug me.

The other day it appears that my MEP had a catastrophic failure. The off grid system went down even though the generator should auto start. Went to go and manually start it and it just made this weird whirring sound. The engine was not cranking over at all. I could see the flywheel in the generator housing spinning quickly but the fans and belts only slightly jolted then did not move at all. Put a socket on the crankshaft pulley and it just freely turns. I'm guessing that is all not good, unless someone has other input.

Anyhow, scrambled to find another local mep-803a. A guy has one 3 hrs away so not super easy to go check out. He sent me a video of it starting and running. Started up fine but had the same hazing my old one did. Was not able to observe it get to temp so not sure if hazing gets better. I'd be happy to pay what he's asking but annoyed this one might also haze and run "dirtier" than it needs to. I've seen multiple videos of mep-803as running online that seem to have zero haze.

Any thoughts would be appreciated

 

[WWRD99]

I've had an Mep-803a for a couple years. We live off grid and so it runs quite a bit, probably at least 1000hrs over that time.

It's always had an exhaust haze size i've owned it. Positive its not coolant as never have lost a drop. Pretty sure it's unburnt fuel haze. Replaced the injectors with aftermarket ones. Played around with the timing shims, even tried to disable fuel to individual cylinders but nothing seemed to make any difference. Always started up no problem, even in the cold without preheat. Never checked compression as seems no easy way to check without fabricating a custom injector. Eventually just lived with it but it did bug me.

The other day it appears that my MEP had a catastrophic failure. The off grid system went down even though the generator should auto start. Went to go and manually start it and it just made this weird whirring sound. The engine was not cranking over at all. I could see the flywheel in the generator housing spinning quickly but the fans and belts only slightly jolted then did not move at all. Put a socket on the crankshaft pulley and it just freely turns. I'm guessing that is all not good, unless someone has other input.

Anyhow, scrambled to find another local mep-803a. A guy has one 3 hrs away so not super easy to go check out. He sent me a video of it starting and running. Started up fine but had the same hazing my old one did. Was not able to observe it get to temp so not sure if hazing gets better. I'd be happy to pay what he's asking but annoyed this one might also haze and run "dirtier" than it needs to. I've seen multiple videos of mep-803as running online that seem to have zero haze.

Any thoughts would be appreciated

Well in the general rule with engines if one end turns over then the other doesn't the crank most likely broke. Possibly flywheel bolts sheered off or something odd like that could maybe do the same thing. Sounds like you really need the set so spending time to take it apart might not be feasible. It is nice to have good spares though if you get the other one. As far as the haze or smoke that can be tough to figure out but most I've heard and seen it's from wetstacking or not loading the genset enough for a long period of time. Getting the new one load tested for a long period should get rid of it if it is from that. I'm sure others will answer this as well that know more than I.

Sent from my SM-S906U using Tapatalk

 

[Ray70]

Agree with the 2 most likely failures on your current 803.
As for the haze, a good running machine really shouldn't have any noticeable smoke when its running and warmed up unless you are in the 75%+ load range.
You'll get a little smoke at start up, but it should clear up within a minute or 2.
Continued smoke could be caused by wet stacking, otherwise I'd suspect other mechanical issues.
Anything from metering pump issues, injector issues to cylinder issues, piston rings, cylinder wall scratches, low compression etc.
One thing I saw several years ago was an 803 with low compression in 1 cyl. and persistent light smoke.
Turned out to be a slightly bent connecting rod which lowered the piston height just enough to lower compression.
Perhaps it had once been hydro locked just enough to bend the rod a little.
It's possible yours had a similar issue and maybe a rod eventually broke and also snapped the crank or sheared the flywheel bolts.
Disassembly is the only way to know.
Keep us posted if you tear into your machine. it will be interesting to see what happened!

 

[Guyfang]

So how much load were you normally pulling when the set ran fine?

Sounds like your flywheel bolts came out, or sheared.

 

[peapvp]

These type of failures are usually several faults accumulating over time and then culminating randomly, causing the complete failure of a system.

That's how airplanes fall out off the sky

The fact that the system was in auto start mode is pretty much irrelevant.

Looking at the fact that the flywheel rotates by activating the starter indicates that the final failure most likely occurred while the set was operating and producing power and then shutting itself down.

I looked at our records and it does not appear that we have you as customer in our database.