Another runaway

[jimmcld]

The oil level has been high in my M816 since I got it. After my first runaway, I decided I had better get rid of the excess oil. I drained out two and a half GALLONS. It is now at mid range on the stick. The oil that came out looked fine, no water or anything else that I could seel Well, after using it for about an hour today, I had another runaway. It was at idle the whole time I was using it and I just reved it up a little as I was putting it away when it happened. I pulled the emergency stop with no effect at all. Before I could do anything else, it went back to idle. Seems to run fine again.

What am I missing?

 

[velociT]

Gnomes man..... gnomes....

 

[fstfrdy]

chk turbo if blowing oil into intake side can cause runaway. only way to shut them down is to stall them out(put in high gear hold the brakes and let out the clutch) or smother the intake of air. have had this happen with civvy road trucks. your seals could be failing and letting oil into the intake

 

[papabear]

er...the 816 has no turbo? Should be an NA 250 Cummins.

Was it a true "runaway" as in crazy RPMs or just a super fast idle and then back to normal?

Check the fuel lines.

 

[mckeeranger]

The oil level has been high in my M816 since I got it. After my first runaway, I decided I had better get rid of the excess oil. I drained out two and a half GALLONS. It is now at mid range on the stick. The oil that came out looked fine, no water or anything else that I could seel Well, after using it for about an hour today, I had another runaway. It was at idle the whole time I was using it and I just reved it up a little as I was putting it away when it happened. I pulled the emergency stop with no effect at all. Before I could do anything else, it went back to idle. Seems to run fine again.

What am I missing?

You should keep an eye on the oil level. The level in our M817 started rising. I didn't pay much attention at first, but then the oil pressure dropped and the level had jumped a bunch. It turned out the seals on the injectors were failing and it was allowing fuel to leak into the crank case through the heads. The oil looked fine but was really thin. It had pumped almost 4 gallons of fuel into the oil in a short period of time. I'm lucky I didn't toast the bearings or cylinder walls.

I don't know if that is why yours was high, just saying keep an eye on it.

BTW, that oil/fuel mix burned great in an M35A2 multi.

 

[papabear]

Good call mckeeranger. Guess I assumed it was just oil...not oil/diesel mixed.

Take heed jimmcld...he speaks the truth...and the consequenses are severe.

 

[jesusgatos]

Sorry to hear that man. I'm working with Roda Deaco, trying to adapt one of their throttle cutoffs to Mah Deuce engine. I was planning on starting a thread when we got into it.

 

[nk14zp]

Stumps the m816 is not MF.

 

[jimmcld]

er...the 816 has no turbo? Should be an NA 250 Cummins.

Was it a true "runaway" as in crazy RPMs or just a super fast idle and then back to normal?

Check the fuel lines.

It was a true runaway. I don't know what the rpm's got to but it was screaming. It also belched a lot of black smoke.

Actually, it didn't go back to idle because I had pulled the emergency shut off. It just died. But then, after resetting the emergency shut off, it started right up and idled normally.

If there were a lot of fuel in the oil, could that cause a runaway? I know it could do a lot of harm but I don't see how it could cause a runaway.


For the guys posting about the multifuel:
It is not a multifuel. It is a 250 Cummings and it does not have a turbo.

 

[stumps]

Stumps the m816 is not MF.

Yeowch! I didn't look to see where I was! I have deleted my post.

-Chuck

 

[wreckerman893]

Fuel in the oil is what cause my 250 Cummins to run away, if I had not shut off the air it would have gone high order.
If it was sucking oil through the turbo there would be a very thick cloud of white smoke.
Unless the oil level is very, very high it will not cause a run away.
Could the throttle have stuck and then released?????
Maybe the pump linkage needs some lube.

 

[jimmcld]

Fuel in the oil is what cause my 250 Cummins to run away, if I had not shut off the air it would have gone high order.
If it was sucking oil through the turbo there would be a very thick cloud of white smoke.
Unless the oil level is very, very high it will not cause a run away.
Could the throttle have stuck and then released?????
Maybe the pump linkage needs some lube.

I checked the linkage and it seems ok.

How could you tell that you had fuel in your oil?

 

[southdave]

taste? Lol

 

[mckeeranger]

I checked the linkage and it seems ok.

How could you tell that you had fuel in your oil?

If it smells like fuel, or if it is very thin.

In our case it was thin enough to notice a drop in oil pressure. It was also starting to leak through the main seals. It was a lot of fuel.

 

[topo]

a few drops on a hot exhaust manifold . diesel evaporates quicker then motor oil .

 

[wreckerman893]

How could you tell that you had fuel in your oil?

My first clue was when I pulled the dipstick out (after I had shut it down) and the level was still almost to the top of the oil pan.

If I had done my proper pre-start inspection (I was only going to move it across the yard) I would have found out the level was too high.

I had placed a temporary fuel tank on the tool box since my tanks were full of gunk. The pressure of that fuel pushed it past the seals in the pump and caused the problem.

 

[jimmcld]

My first clue was when I pulled the dipstick out (after I had shut it down) and the level was still almost to the top of the oil pan.

If I had done my proper pre-start inspection (I was only going to move it across the yard) I would have found out the level was too high.

I had placed a temporary fuel tank on the tool box since my tanks were full of gunk. The pressure of that fuel pushed it past the seals in the pump and caused the problem.

I read about yours when it happened. I just am not having luck figuring out what is causing mine, but I don't know much about the Cummings motor. I've been told that it could be the IP of the injectors, but neither are easy to check. It seems to me that it is pooling oil in the intake somewhere and then, when it gets to be enough, it sucks it all down until it's gone, and then returns to idle. Does that make any sence?

 

[cbvet]

How can fuel in the oil cause a runaway? Especially on a non'turbo.

 

[fasttruck]

Benn messing around with the hand throttle ? If hand throttle is advanced engine will eventually be found running at full throttle even if hand throttle is only slightly advanced. In my experience this has happened with nh250s in 809 series trucks andx the v903 found in the 10 ton both of which use the cxummins pt fuel pump. They will not follow the throttle like a mack or lsd465 does.

 

[SCSG-G4]

Fuel in the oil gets sucked up through the rings (remember they spray oil on the inside of the piston to help keep it cooler) and adds to the combustible mix. Can happen to almost any diesel engine, especially when the rings are worn. Hint, they seal on the power stroke, under pressure, but run a bit looser on the exhaust/fresh intake stroke. Just think about it for a few minutes.