Is it possible to start a motor ( cat ) backwards and make it pump oil out the air cleaner.

Of all the years I worked on Cats and around them I never heard of one ever running backwards but I have heard of others doing it.It seems to come to mind I,ve heard of the two cycle GM doing it but never seen one so can,t say if it,s true.

It is certainly possible to attempt to start a 9U D6 by pushing or pulling and make it blow oil out the air cleaner if you have the reverser in the wrong position for the direction you are going. I expect most folks figure it out before it actually lights off!

I have heard of trucks choking down going up a hill and starting up backwards as they rolled back down a slope. I wouldn't think they would have much power running backwards, but enough to run with the assist from the truck rolling back down hill. Should be easy to kill it if it didn't die on it's own when you got it stopped rolling/got the clutch in.

Yes they will if they get rolled over backwards as stated before. They just pump smoke out the air cleaner. They will run long enough to dammage things if not shut off right away. The oil pump isn't delivering oil. The fuel transfer pump will pump fuel if it's a piston type but not if it's a gear type.
Later Bob

Yes, but most people usually wake up to the problem quickly, and shut things down. They don't run well backwards, they just sputter and barely run, as the fuel timing is out.
I've had my 237 Mack Maxidyne run backwards, after a stall under load at low RPM .. had Cats run backwards, when a newbie selected a reverse gear .. and the Detroits are by far the worst, for doing it easily, when stalled under load, and the backlash spins them in reverse.
As Bob says, shut 'em down quick, you can do damage to the engine if they run backwards for more than a few seconds. Oil bath aircleaners are good, they wake up the operator real quick to the fact that somethings wrong ..

I've seen it a few times & heard of it a few more. At the local antique tractor pull this spring, a guy on a JD 70 Diesel got a bad start & killed it, the sled sorta jerked it back...he clutched it, & when he tried to take off again, it backed up. He was completely bamboozled, he kept trying to go forward, looking what gear he was in, & it kept backing up! Several people were yelling that it was running backwards, there was smoke coming out the air stack...somebody finally ran out & told him to shut it down. He restarted & pulled OK, but I'm not sure he ever figured out exactly what happened...embarrassing in front of a crowd...I think most Diesels are capable of doing it if killed hot & rocked backwards.

It is. Many years ago we used to pull start the old D7, one nite i put it in the wrong gear and it covered me from head to toe in black oil out of the air cleaner. Looking back it was funny.

Common thing on hand cranked engines for them to start backways,the oil blown out would not be oil from the sump but from the air cleaner so if it had a dry air filter there would be no oil,an engine running backwards will usually stop fairly quick from the lack of lubrication to the mains due to the oil pump been directional,on marine engines that are designed to run in either direction the pump problem is overcome by using a plunger type pump operated by a camshaft as it will pump the oil regardless of which way they are turning,one would have to go out of ones way to start a Cat engine backways except towing or pushing as stated above,but they will start backways.
AJ

I've seen a Cat 3208 run backwards after a stall on a hill. .smoke coming out from under the hood. Same thing with a truck that had a 6-71. By far the worst of the diesels is the Jimmy 3-71 in winter. I used to have to try to start an air compressor equipped with one of those. .it wouldn't really run backwards but it would cycle back and forth. You could see the fan turn one way and then the other. The only way was to shut it down and try to restart. .usually after several restarts it would settle down and run right. A real pita in subzero temps!

I've known a D4 2T run backwards when pulling trees over, the operator (my Dad) didn't have enough throttle on, the engine stalled, the tree pulled the rope back off the drum and the engine ran backwards for few seconds.