Puffing smoke

[PaulS]

I was mowing the lawn with my 2084 with a command 20 and thought I noticed an occasional puff of white smoke. Well by the time I finished about 10 minutes later it was more than a puff. From what I could see the smoke was not coming from the exhaust. When it cooled down Eric and I really looked at it and first the oil level was way down from being full when I started and oil was everywhere in the engine compartment. The engine sounded fine so I suspect a rear engine seal has left go. We added enough oil to be safe and started it up and moved it about 15 feet and everything sounds good but got no oil leak. Could the seal be just going bad and works sometimes and leaks others or do I have a diff problem.

We removed the engine and I began cleaning up the side covers, engine plate, frame in front of the firewall and rear shroud cover which was really icky. From the flow pattern the oil seems to be coming from the back to the front being blown by the fan.

What kind of problems are there in removing the flywheel to have a good look at the seal. Also is there a front seal on this engine. We did not see where one was listed.

I was charged a large bill for head gasket a couple years ago and they stated the charge was mostly because they had to remove the engine. Eric and I had that engine out in about 20 minutes, I think I was overcharged on that repair.

[Matt G.]

Yes, there is a PTO end seal as well as the flywheel end one. I'd replace both while you are in there. It's not difficult to remove the flywheel to get at it.

[Sam Mac]

Paul

As Matt said change both while you have it out. Also take a good look at the valve cover gaskets and the head gaskets. Had a CH18 with a broken valve cover bolt and it was allowing oil to blow onto the exhaust. Didn't have a mosquito problem when it was running. I also used some Permatex Ultra Gray on the valve covers when I put them back on, got tired of the dribbles.

[Leadslingingdaddy]

Check on top of the engine also where the gov'nr is located...should be 4 10mm bolts there..They have the ability to work loose also..

[PaulS]

Thanks for all the info. Within the past 3 months I have replaced the breather filter and both valve covers as mine were cracked and leaking. With the amount of oil in the fan shroud I would guess my current problem lies in the oil seals. Eric thought that possibly my use of a automotive oil filter created pressure to blow out the seal(s). The one I have matches in every way to a cub cadet oil filter. I know that automotive oil filters are not to be used in the tranny but could be used in the engine. I am planning on replacing both seals while I have the engine out. When we replaced the oil breather filter we did find one of the bolts was loose enough to remove with your fingers. The engine runs fine and uses very little oil and sounds great when running just like a super should. When I was mowing when this started I was not even running at wot, only about 3/4 throttle. About all I was mowing was plantain shoots and buckhorn stems so it was not even working hard.

[Matt G.]

Why aren't you mowing at full throttle? The engine is designed to run under load at full throttle, and you are actually working it harder by mowing at 3/4 throttle, and the cut quality is probably suffering, too. You are not doing the engine any favors by mowing at less than full throttle.

[PaulS]

Matt my lawn is mostly dead and what was growing was not thick at all and it was a hot day. Last year I had some running hot problems and thought I would take it easier on the engine guess I was wrong. I did find what I believe was my overheating problem. After removing the metal encasing the heads I had an accumulation of junk and baked on gunk. Since I made all the fins I could reach nice and clean again she ran good. My schedule now includes annual removal of all tin shrouds and have at the fins. I have been thinking of some sort of shield under or around the rear fan shroud to keep the grass and dirt from the mower deck from being sucked into the fan/flywheel area and being blown under the tins to get stuck in the fins. I do not want to restrict any air flow, just redirect it away from being drawn from below.

[mrcubcadet]

Originally Posted by Matt G.

Why aren't you mowing at full throttle? The engine is designed to run under load at full throttle, and you are actually working it harder by mowing at 3/4 throttle, and the cut quality is probably suffering, too. You are not doing the engine any favors by mowing at less than full throttle.

Full throttle is not always the "coolest" way to run an engine. Such as the 1782 I have...It has a new D640 at 400 hrs from over heating. Keep the throttle at 3/4 throttle, it will stay under 200 degrees..I haven't tried it at full throttle, myself, but the PO says that it will climb over 200 degrees if you run it at full throttle for a long period of time.


The more revolutions, the more thermal energy is made.

[Pa Cooner]

Air cooled engines are different due to the cooling fan being attached to the crank via the flywheel. The faster you spin it, the more cooling air you get. Where water cooled engines have antifreeze surrounding the cylinders to remove the heat.

And a side note: if your diesel is overheating after running wide open for a period of time, you should have radiator cleaned. More than likely some of the passages are begining to plug and it doesnt have the flow it used to have.

[Matt G.]

Originally Posted by Pa Cooner

Air cooled engines are different due to the cooling fan being attached to the crank via the flywheel. The faster you spin it, the more cooling air you get.

And in the end, the diesel is 'air-cooled' too...the coolant is cooled by air moving through the radiator, and the amount of air that is moved through the radiator is directly proportional to the speed of the engine, just like it is for an air-cooled engine. I totally agree, the cooling system needs cleaning out if it's overheating. That isn't normal and it should be no problem to run it at full throttle.