DISCUSSION - Slobbering Multifuel Cure?

[FSBruva]

So, in the PS magazine section, there is an issue about "why do the multi's smoke and spit oil out the exhaust?" and the answer came back to, "too much idling or low speed operations." A TB is mentioned, (which I can't find - TB 750-981-2), and the solution is to get the truck up to highway speed while loaded for 100 miles.

The topic then becomes - why is that the solution, and what causes the problem in the first place?

The end result (with respect to the exhaust) after a loaded highway trip, as we can all remember from Bjorn's travels, is that the EGT's will climb. So why would that help a oil slobbering deuce?

Anyways, just wanted to pick the collective brain of the think tank.

Matt

 

[WillWagner]

The newer Cummins engines have sort of the same issue, but they also put soot out the joints due to the EGR pressures. N14s will slobber oil out the manifold joints if idled too long, and Cummins had no solution for this, except, don't idle it for extended periods. Those have guide seals. The new ISX and M11s will do the same thing, valve guide seals too, as do the Cat midrange engines. Both Cummins and Cat have released a "diaper" that clamps over the manifold joints. I know the Cummins ones won't fit, but the Cat midrange engine manifold looks almost the same size as the LDT 465. After I got my truck running, I noticed oil out the joints, I know I shouldn't idle it that long, but wondered if the Cat diapers would fit. Maybe I should get a set and see if they fit. I can deal with the oil smoke after long idle periods, but the slobber sure makes a mess.

 

[Stretch44875]

Maybe the engine isn't hot enough, or loaded enough, to get a complete burn. What ever unburned fuel is left gets pushed out the exhaust. A long drive gets everything hot and cleaned out.

Personally, my deuce loves to be run at hwy speeds. After 20 miles or so, the engine really perks up.

Dennis

 

[cranetruck]

I have to push that radiator cover again....use it!
Even when the ambient temp is 60-80F. The engine will get up to operating temp much faster.
The only "slobber" I ever had out the exhaust was rain water mixed with soot and using an empty tin can to cover it when not in use has cured that little problem. It used to spit all over the side after a rain storm.
I probably run the engine at low rpm's more than most because of the crane operation. I usually run it at idle for no more than 5 minutes, but after that the rpm will stay at 1,200 or so, sometimes for hours. With the radiator cover, the op temp then stays on 170-175F.
After long periods of low rpm operation, a drive will "clear the pipes", it smokes like mad for a mile or so, but cleans up nicely and will run without much visible exhaust thereafter.
As far as slobber around the cylinder head, in particular on the passenger side, yes there has always been some, but not enough to worry about. Read somewhere that there are fine "vent" holes in the gasket (PS magazine ?) on that side.
I think that the engine op temp is the key to all this slobber, keep it up where it belongs! Use a radiator cover of some sort, I have a permanent custom cut piece of plywood and use it all year. May have to remove it for the desert drive next month, but I'll wait until then (see image).

The EGT has no relation to slobber as far as I know.

 

[Squirt-Truck]

Bjorn, I still say you have a cooling system problem. Excess bypass. We checked my truck with a pyro, it comes to 178 within 30 minutes at idle, within 15 if moving. Once it makes thermo temp never drops below it. At 175 degrees the top tank of the radiator is just warm, not hot. A few weeks ago we were in the mountains with the truck, temp was low 50's, it is 10+ miles down from Fort mountain, third and 4th gear, never got below 180. I have no radiator cover. This past weekend, had a towed load of 22,500# (5-ton dump in flat tow), never ran over 200, even in the mountains, 3rd gear pulls.

On this topic, I run at 180-200 degrees, no slobber, virtually no smoke, except under heavy load or running up the gears. Let it idle for 10 minutes, and it will kill all the bugs for a quarter mile. I agree, they like to run hot and hard. Hours at a time at 2300 and 47 mph.

 

[cranetruck]

My cooling system is very efficient.

 

[WillWagner]

Nah, not a cooling problem. It's just a little oil passing thru the guides. It's kinda of normal, especially after an engine gets time on it and has no guide seals. It is a very common problem in reconditioned heads. Take Cummins v.s Diesel Recon. The Cummins valve guide max diameter is .0025 smaller than the ReCon "new" guide dia. spec. Can't tell you how many heads we have replaced for this issue. Back in the day when labor rates weren't $100.00 per hour, we would r&i ReCon guides, ream them to Cummins spec, and have no other issues, easy 250k mile heads, now, forget it, they're remaned in MEXICO. They're junk. A fresh rebuilt engine, pushing oil out the exhaust if it's idled more than 5 or 10 min. Thats acceptable?

 

[FSBruva]

Where does the oil come from, though? Past the piston rings? Or past the seals in the turbo?

Bjorn - when you're running the knuckleboom for long periods, how much does that load the engine? I imagine you don't have the problem because 1. You're above the 800-1000 rpm idle zone 2. you're not running the motor with no load.

I think it has already been established that the deuce loves to run, and mine is no exception. I am just curious how I can prevent the slobber when I have to let it idle for 20 minutes to get warm in the winter. Electric oil pan heater? Run it at high idle to warms it up once the oil pressure is up?

Matt

 

[Recovry4x4]

Matt, in my humble opinion,1000 rpm or better for extemded periods of idle are much more forgiving on the truck that a flat idle of say 800 or so. Also for those whos trucks idle below that, you're killing the truck with vibrations. Headlights take a beating during those low idle periods.

 

[cranetruck]

FSBruva: "I am just curious how I can prevent the slobber when I have to let it idle for 20 minutes to get warm in the winter. "

Matt, how warm does it get after 20 minutes in the winter time? I know Squirt-Truck firmly believes that I have a cooling problem, but that aside, in the winter at say 20F, my engine will never reach op temp w/o a radiator cover. Even with it I need to keep the rpm at 1,000 or more to warm it up. Another question, Matt, if you wipe the engine clean before starting it, will it always produce a noticable slobber?
At Kenny's , last Feb, we pressure washed parts of the truck, my effort to clean the engine was halfhearted and some oil was left on it, so I can't really tell how much new slobber is produced after a run. The engine is always a bit oily. I just don't worry much about it. You have a good point, though. I'll try to find the note on the "vent" holes.

 

[FSBruva]

To be truthful, my warm ups in the dead of winter usually last closer to 30-40 minutes. I have the radiator cover that I use in the winter, but even with the vent all the way closed, it still takes a while to warm it up.

Perhaps "slobber" isn't a good word. I know most diesels are externally lubricated, and that's not my worry. I am talking about oil coming out of the exhaust pipe in liquid and/or smoke form. I notice a little bit of oil on the outside of the exhaust pipe right where it connects to the turbo after prolonged idle, but that is intermittent. A good run on the highway results in a clean bill of health, but whenever I first start, the first accelleration leaves a light blue plume, regardless of the engine's temp. I thought it was seals in the turbo going bad, but the PS article makes me think it's just a matter of how I run the deuce. Maybe just get a few tons of gravel in the bed to make my commute better for the truck?

Matt

 

[WillWagner]

If it slobbers out the exhaust, and you have no massive amounts of oil out the road draft/crankcase vent/blow by tube, that will usually indicate a cylinder problem, it is usually the valve guides/seals. If you want to be sure, remove the turbo and exhaust manifold, find a way to plug the turbo oil feed line and drain, then idle it. Look for the oil streaks and that will tell you where the oil is comming from, valve guides or cylinder. There is also dye available to put in the oil. Run the engine at idle and hit it with a UV light and see where the glowing lines come from. Rule of thumb for older engines was to idle it at 1000 or a little above to stop the oil slobber issue. If it was a turbo problem, there would be ALOT of oil smoke the more you accelerate, it wouldn't go away as you drive. If there were a cylinder issue, there would be a constant haze of blue smoke as you traveled down the road getting in and out of the throttle and a large amount of oil dripping out the blow by tube.

 

[M35A2]

To be truthful, my warm ups in the dead of winter usually last closer to 30-40 minutes. I have the radiator cover that I use in the winter, but even with the vent all the way closed, it still takes a while to warm it up.

Perhaps "slobber" isn't a good word. I know most diesels are externally lubricated, and that's not my worry. I am talking about oil coming out of the exhaust pipe in liquid and/or smoke form. I notice a little bit of oil on the outside of the exhaust pipe right where it connects to the turbo after prolonged idle, but that is intermittent. A good run on the highway results in a clean bill of health, but whenever I first start, the first accelleration leaves a light blue plume, regardless of the engine's temp. I thought it was seals in the turbo going bad, but the PS article makes me think it's just a matter of how I run the deuce. Maybe just get a few tons of gravel in the bed to make my commute better for the truck?

Matt

I am curious why you are idling your engine for this length of time in the winter? I was under the impression that the data plate says run the truck engine for 5 mins before running engine at higher RPM's.

More engine wear occurs during start up and in cold engines. Why not idle the truck at idle for 30 seconds just after start up so the oil has circulated through the engine, then run her at 1000RPM until the 5 mins is reached, then get in and drive the truck using gentle RPM's until engine is at operating temperature? A cold engine at idle in cold conditions produces a lot of moisture.

 

[M35A2]

To be truthful, my warm ups in the dead of winter usually last closer to 30-40 minutes. I have the radiator cover that I use in the winter, but even with the vent all the way closed, it still takes a while to warm it up.

Perhaps "slobber" isn't a good word. I know most diesels are externally lubricated, and that's not my worry. I am talking about oil coming out of the exhaust pipe in liquid and/or smoke form. I notice a little bit of oil on the outside of the exhaust pipe right where it connects to the turbo after prolonged idle, but that is intermittent. A good run on the highway results in a clean bill of health, but whenever I first start, the first accelleration leaves a light blue plume, regardless of the engine's temp. I thought it was seals in the turbo going bad, but the PS article makes me think it's just a matter of how I run the deuce. Maybe just get a few tons of gravel in the bed to make my commute better for the truck?

Matt

I am curious why you are idling your engine for this length of time in the winter? I was under the impression that the data plate says run the truck engine for 5 mins before running engine at higher RPM's.

More engine wear occurs during start up and in cold engines. Why not idle the truck at idle for 30 seconds just after start up so the oil has circulated through the engine, then run her at 800-1000RPM until the 5 mins is reached, then get in and drive the truck using gentle RPM's until engine is at operating temperature? A cold engine at idle in cold conditions produces a lot of moisture.

 

[M35A2]

To be truthful, my warm ups in the dead of winter usually last closer to 30-40 minutes. I have the radiator cover that I use in the winter, but even with the vent all the way closed, it still takes a while to warm it up.

Perhaps "slobber" isn't a good word. I know most diesels are externally lubricated, and that's not my worry. I am talking about oil coming out of the exhaust pipe in liquid and/or smoke form. I notice a little bit of oil on the outside of the exhaust pipe right where it connects to the turbo after prolonged idle, but that is intermittent. A good run on the highway results in a clean bill of health, but whenever I first start, the first accelleration leaves a light blue plume, regardless of the engine's temp. I thought it was seals in the turbo going bad, but the PS article makes me think it's just a matter of how I run the deuce. Maybe just get a few tons of gravel in the bed to make my commute better for the truck?

Matt

I am curious why you are idling your engine for this length of time in the winter? I was under the impression that the data plate says run the truck engine for 5 mins before running engine at higher RPM's.

More engine wear occurs during start up and in cold engines. Why not idle the truck at idle for 30 seconds just after start up so the oil has circulated through the engine, then run her at 800-1000RPM until the 5 mins is reached, then get in and drive the truck using gentle RPM's until engine is at operating temperature? A cold engine at idle in cold conditions produces a lot of moisture.

 

[ken]

The oil smoke from the exaust after low speed use is likely from the turbo. They have lybrinth seals in them (old tech). There is a small channel on the comperssor side that brings charge air to the lybrinth seal. This pressure counter acts the thrust and pressuizes the outer parts of the bearing housing. When you idle for long periods there is too low boost pressure and the oil can excape. After running it hard the oil that got out will be burned. This also restores the pressure and seals off the bearing housing

 

[FSBruva]

AHA!!! Thanks ken!!

M35A2 - I am getting my truck warmed up so that I don't freeze my ass off on the way to work. Plus, I don't really want to worry about being gentle on a cold engine. I would rather let it warm up and drive the hell out of it.

Matt

 

[ken]

It is always a good idea to let it warm up before driving it. No matter how hot or cold it is outside. And never forget to let the turbo cool before shutting it off. It will last a lot longer. A small amout of leakage from the turbo shouldn't hurt anything. Besides, the exaust pipe won't rust as fast.

 

[FSBruva]

Exactly, ken... thanks for helping me breathe a sigh of relief. I was worried that a turbo acquisition was needed in the near future. Now I know better!

Matt

 

[houdel]

OK, I've got to throw in my $.02 on this cold weather warm up issue. 20, 30, or 40 minutes of warm up is a huge waste of time and fuel, not to mention unnecessary wear on the engine! You are better off to drive the truck after a minimal warm up and get 30 or so miles on the odometer than wear your engine out at idling it.

After 5 mins of idle, the pistons and inner wall of the cylinders are at or near normal operating temperature. Get in and drive it! The only thing not adequately warmed up after 5 mins is the oil, drive moderately for a few miles and the oil will be just fine.

Idling the engine for extended periods of time just to warm up 32 quarts of coolant is crazy. If you want a nice warm ride, install a recirculating electric coolant heater. The fuel savings alone will pay for the heater and you'll save wear and tear on the engine. Your engine has a finite service life, better to use it driving the truck than warming water!