mep-802a engine oil leak

[zarathustra]

If I let it run a while it leaks oil on to the fuel solenoid side. It is tough to see where it might be coming from. I'm thinking that the crankcase door gasket might be bad... but that's more guess than anything else.

Two questions:

Has anyone run into this problem, and what was their fix?


Does anyone know of a source for the 802a gaskets, specifically the crankcase door gasket.

I suppose I could make one, but it'd be handier if I could simply buy one. (and not pay 200 - 300 dollars for one from China)

thanks in advance

z

 

[Light in the Dark]

There are numerous seals on this engine... you really need to wipe it all down, and run it to track it down real time. I've had a front crank seal go bad, spraying oil all around the cabinet. Gaskets are available separately through both Onan and LP supply chains.

 

[Ray70]

I second that motion. You have to clean it and see where the leak is coming from. It could be the ( orange ) push rod tube seals, side cover gasket, even the oil pressure sensor hose/fitting.
No sense guessing. if it's the side cover, you can get just the gasket pretty cheap or I see an entire gasket kit on ebay for only $89.
Find the source, then we will go from there.

 

[builmord]

just a thought. could be blow by coming out of the dip stick hole

 

[zarathustra]

Thanks for the replies.

I've found that most mechanical devices of a single model / type tend to have common failure modes. I am sure that I am not the first person to have an oil leak on a 2 cyl Lister Petter engine. So, I was looking for a common failure mode for oil leaks for that engine. Sorta lookin' for a list of the "usual suspects" on oil leaks.

Kinda hoping that someone who dealt with these units in the military might have experienced a fix for oil leaks on the MEP's.

I do like the dipstick O ring blow by idea.... there is some oil on the dipstick, oil fill area, but it just seems like there is too much in the battery area to be squirting out the dipstick hole. Besides there isn't any oil on the top of the battery. And since there is no oil at all below the front of the engine or the other side of the engine I'm not thinking it is a seal on the shaft.

I've tried cleaning it up and running it, but it doesn't manifest itself in a short run.

Thanks again for the replies

z

 

[Guyfang]

I have several times taken a bath from blow by. You are supposed to have vacume on the crankcase. So simply start it up, and pull the dip stick. There is a procedure to test test for blow by. Simple one is to start the set. Take out the dip stick. Place a small piece of paper on the dip stick hole. If it gets sucked down, vacume is present. Blown away, it's not present. You can also build a water manometer. Instructions are in the TM.

Take the top off the set. Use degreaser on the set. Get it clean. Place the top on the set. Run it. In my experance, it's push rod tubes or valve covers.

 

[zarathustra]

Aha!!!!! I'll give that a look-see

 

[dav5]

The oil pressure sensor hose was the problem on mine. I don't think it was ever tightened properly

 

[Bmxenbrett]

It dosnt really matter if theres a common oil leak area because you would still need to clean it and run the engine to see where your specific engine is leaking.

I believe ebay has a whole gasket kit for less than $200.
https://www.ebay.com/itm/Full-Gaske...590736?hash=item3fb199de10:g:I4gAAOSwVMJb7kNR

The onan brand one is over $450.

 

[Bmxenbrett]

Scratch that one above. Heres a genuine cummins brand one in the box.

https://www.ebay.com/itm/OEM-MILITA...352721&hash=item33e0025187:g:B2QAAOSwRTVaYOoq

 

[builmord]

be careful to remove all shop rags, paper towels etc. my mistake was leaving a small rag just outside the open door to the engine compartment. when I started the unit the fan sucked it in and it got caught in and shredded the fan belt. good luck on finding the leak

 

[Ray70]

Lucky it was just a shop rag! I was recently working on an 803A with the top cover and exhaust manifold off... at night, using my snap-on flashlight looking closely at the exhaust ports for signs of smoke, i had a lapse of attention and stuck the butt end of the flashlight and my pinky finger into the fan! it chopped the magnet and bottom off the flashlight and for a split second I thought me and my pinky finger had parted ways, but luckily I came out with all 10 fingers still attached.... and just a minor flesh wound.

 

[Guyfang]

I have a nice little scar on my right arm, right at the elbow. Fooling with a electric fuel pump. At night, flashlight in one hand, trying to get the bottom off the pump, to let some water out. This 52300 Stewart and Stevens set had three pumps directly under the fan. Someone came in and grabbed me by the shoulder. I jumped. I almost crapped my pants. Blood running down my arm, and I was choking this guy for all I was worth. I have immense respect for fan blades.

 

[zarathustra]

I think I need to teach myself a little more about diesel engine blowback and crankcase pressure (vacuum?).

 

[Guyfang]

This engine has positive VACUUM.

Open TM9-2815- 252-24. Look at PDF reader page 34. Paragraph 3-5

 

[Light in the Dark]

I think I need to teach myself a little more about diesel engine blowback and crankcase pressure (vacuum?).

Not all diesels are like this... some have vacuum, and some have pressure. The 802 and 803 have a slight vacuum to the case (which can be tested by the TM, or simply with a piece of paper informally). My early 90s ford 7.3 IDI has positive crankcase pressure, so it requires a CDR (crankcase depression regulator) valve to regulate the pressure so it does not become too great.

 

[builmord]

my only experience with blow by is with my unit. amazing how a nearly invisible oil mist looks like a major oil leak after a couple hours of run time. funny how the battery was clean but sat in a puddle of oil. check your oil level, I found that filling to the max exacerbated the problem

 

[Dieselmeister]

I recently had a leak on my truck engine. Ordered some Tracerline UV dye for oil (they make one for oil and one for coolant), and a cheap UV flashlight off the big "A" site. Amazing how easy it was to find the leak in the dark. Any seepage with the dye will glow brightly. (And so will your driveway, and anything else you get the dye on!)

 

[builmord]

I guess that's as good as you can do. seems at least you cam see the problem area