mep-802a running temperature

[skwishst]

I have been trying to get my freshly rebuilt mep-802a to show some temperature. The engine was completely rebuilt and has a new thermostat and water pump and I have fresh coolant in the system. After running without any load for about 15 minutes, the gauge is only reading about 110 degrees and I can confirm this with an IR sensor and by touch. The upper radiator hose does have a little temperature (the 110) but the lower hose is pretty much cold. I had the radiator flushed and patched a few cracks.

How long should it take to come to temperature with no load? I am thinking of pulling the thermostat (Stant 4535 to see if that is the issue but i am not even at a temp that it should open.

 

[Guyfang]

15 Min is way more then enough. Put a load on it. at least 70%.

 

[Light in the Dark]

Yeah throw as much load on it as you can and keep an eye on it. Have you been testing it only in this cold weather?

 

[skwishst]

So it is about 25 degrees outside today which is cold. I will put a load on it but I do not have it wired up yet so only have the convenience plug. That appears to be only 10 amps so no chance of any real load there. I am waiting on a few items to do the wiring and then I will hook up my various heaters and toaster ovens for now.

 

[Daybreak]

Have you burped it yet?
You will want to keep trying to add coolant. Fill it up, tilt the unit some, use the dead crank to spin it some, add coolant, dead crank some more etc. You need to get coolant all through the block, hoses, and radiator.

 

[skwishst]

I did a little tilting and dead cranking, but it really was not taking much more coolant. I will do a few more cycles of that.

 

[Light in the Dark]

In the future if you are replacing the T-stat, you can just backfill the system through the water pump into the water jacket and it will bring the fluid in the system up to that level. You can then top it off at the radiator fill when its all put back together.

 

[skwishst]

Great idea! I have put one of those filler funnels on there, filled up the funnel and cold cranked the system. Also, since the wire in the lower hose was rusted i had removed it and i was able to squeeze the lower hose and see the coolant flow back into the funnel. I think it looks pretty good on the coolant being filled. Later the week i should have all i need to wire and do a real load test

 

[Light in the Dark]

If you wanted to swap out the hoses for one without rust, I have them available in the classifieds.

 

[skwishst]

ok, so I got it all wired up.


went out to go test it again today, and I have no oil pressure and black smoke. When I turn it over by hand, I don't get anywhere near the resistance I got when I finished the rebuild.

Do you think I smoked the rings? There was some oil coming out of the exhaust when I was running before, but I figured I needed to get to temperature to really seat the rings.

 

[skwishst]

Thinking a minute, it clearly is not the rings since it starts. But it does not have oil pressure, lower than normal RPMs, low amps on the battery charger. I will spend some time with the TMs, but any input would be appreciated.

 

[frank8003]

I did not find this but here it is

FM 5-424: Theater of Operations Electrical Systems - Generators

www.globalsecurity.org

 

[skwishst]

ok, using TQM-9-6115-641-24, section 2-91 'Oil pressure sender' paragraph 2-91-1 'Testing', I get 250 Ohms at rest and 140 ohms running. This suggest the oil pressure sender is bad. Should the generator run with a bad oil pressure sender or should the pressure fault cause it to cut out? If it can run with a bordline sender, would the behavior of not coming to full RPM make sense?

 

[skwishst]

also, i pulled off the intake hoses and exhaust to turn it over by hand and got nice resistance and clear compression. even got a puff of exhaust smoke.

 

[Light in the Dark]

The sender is for the gauge. The oil pressure switch would be what talks to the fault panel.

 

[skwishst]

ok, so if have have a bad sender, that could explain why my gauge is reading no pressure but the generator still starts.

 

[Light in the Dark]

When you replace the sender, its a great time to consider adding a manual oil pressure gauge at the T right there. Its been covered in the forum before (I've actually done it to my personal machine, a nice bit of 'extra' piece of mind for me).

 

[skwishst]

I found the posts and will price out some parts.

Also, I think I know the main issue. When I pulled the exhaust off, I notice one side of the manifold was all black and sooty but the other side was clean. I think one of the heating element (glow plugs) are bad and I am running on one cylinder. I will pull both tomorrow and test them. This would explain the low RPMs, black smoke in exhaust and low power. If this turns out to be true and I have one bad heating element, would you guys suggest replacing both?

 

[skwishst]

I have added the manual oil pressure and it reads over 40 PSI

The new sender does not seem to make any difference and when I turn to the prime, the oil pressure gauge actually deflects down until it pegs out and when running it does not read at all.

I started to walk through the gauge testing (9-6115-641-24, section 2-41-2) but i am not sure where the Land R or set Voltage adjust potential meter is. I see on the voltage regulator the Range Adjust but not sure about the terminals mentioned. Either way i know i have oil pressure.

The glow plugs seem to be fine but the generator is still running under power with black smoke. In the TM 9-6115-641-24 trouble shooting section 6 (Engine does not develop full power), i can walk through all of 6 and 7 with no issues (I am using standard Diesel in NJ). Step 8 states black or grey smoke in exhaust and resolves to 'notify next higher level of maintenance'. What does that mean? Is the another section or TM that is the next higher level?

I will re-bleed the fuel system and do a crankcase vacuum test as per 9-2815-252-24 trouble shooting.

 

[DieselAddict]

If the engine is staying cold you may get a little black smoke. How much black smoke are you getting? A little haze or rollin' coal? A short video of the exhaust would be good.

Black smoke with low power suggests an issue with airflow in or out of the engine. Before you rebuilt the engine did it consume a lot of oil? Is the muffler clogged?