Diesel Running Backwards

[Bearsixty7]

Started up my '97 F250 7.3L once and it shook and sounded terrible! I shut it off, checked all the gauges looked under the hood and couldn't figure out what happened. Started it again and it ran fine. This happened a second times weeks later and I repeated the whole process and when discussing with some fellow Powerstroke owners they said it was running backwards and it was because I wasn't holding the key on long enough to make sure the starter rotated the engine the correct way long enough to fully fire. I never put it in gear to confirm. From then on I always just held the key on a second longer and it never did it again.

 

[Hoobie]

I had the same thing happen 5 years ago. Using winch at low rpm I stalled the engine pulling a heavy log. I let go of the control rope instantly and it started backwards. Winch wouldn't pull, hydraulics not working, wouldn't rev up, and oil light on. I shut down immediately and restarted and it ran fine. On inspection the secondary air filter was blackened somewhat and smelled like exhaust.
900 hours later all is well.
I now adjust up the rpm to suit the pull load

 

[Norm W]

Detroit Diesels were noted for that. New drivers trying to start on a hill would have it happen. If it had an oil bath air cleaner there would be oil all over the ground.

 

[MHarryE]

I was testing a prototype with our first common rail injection, had it instrumented testing max hill climb. I ran it to stall, it began rolling backwards, and darned if it didn’t start running. I downloaded the data and confirmed. Engine didn’t think that would happen but they figured out a way to turn one backwards on a test stand. Sure enough they duplicated it, but the timing was way off. Fuel from the return fed the high pressure pump so the rail stayed pressurized but timing was like 40 degrees BTC. They modified the crank sensor to detect running backwards because it was a bad thing. The day following my test the engine threw at least one rod and destroyed the block. Like I said to Engine Division, better I discovered the issue than a customer.

 

[WM75Guy]

Had a rookie backing a 1970 Mack CF600 fire truck with a manual transmission into the bay. He lugged it down till it rolled forward and started running backwards. Driveway was slightly uphill, after it stopped and started running backwards it shot into the street. He pulled the fuel shut off to kill it. It started right up, running correctly. We had to change the air cleaner and his shorts after he got it into the bay.

 

[number two]

Detroit Diesels were noted for that. New drivers trying to start on a hill would have it happen. If it had an oil bath air cleaner there would be oil all over the ground.

Amen to that!
My 1978 GMC Astro 9500 with a Detroit Diesel 6V92TT would do that pulling out of an uphill loading dock with a full load once and awhile.
Imagine my surprise to see the tachometer needle bouncing off the bottom peg and hearing that funny sound!
No wonder so many of those engines had the throttle delay piston thrown away.

 

[mikester]

I've heard of 2 stroke motorcycles running backwards, but never saw it. I hope my tractors never do.

My old Yamaha 2 stroke golf cart ran the motor backwards for reverse.

 

[Victorytree]

Used to happen with Detroit diesels, which were all 2 cycle in the old days.Before paper air cleaner elements, which can catch fire, not a catastrophic problem, if you stop it in short order. Main problem is oil pump running backwards, not providing any oil pressure. Since I qualify as an old timer now, I’ll provide a short history lesson. Detroit diesels, and Cummins, did build some Reverse Rotation engines, which were built to turn backwards for specific applications

 

[Bavarian]

The problem on an engine running backwards is at the bottom of the engine. Not only do run internal parts dry, the mainbearings and piston rod bearings may spin out of their seat. They are seated only one way with a notch in them.

 

[yanmars]

Had that happen with a 2 cycle HD engine in the mid 60s