Runaway Diesel

cpurvis

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Got to witness a 6.7 Cummins runaway in a Walmart parking lot today.

It's a memorable event. LOTS of noise and LOTS of smoke. The owner was more irritated than scared. Said he'd just gotten the truck out of the shop. It was in the shop for excessive oil consumption. My guess is an oil seal in the turbo was leaking and finally let go. It sounded to me like the engine blew; at any rate it was turning so fast I'd never trust it unless it was completely rebuilt.

Hope the thing was still under warranty.
 

reynoldston

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Got to witness a 6.7 Cummins runaway in a Walmart parking lot today.

It's a memorable event. LOTS of noise and LOTS of smoke. The owner was more irritated than scared. Said he'd just gotten the truck out of the shop. It was in the shop for excessive oil consumption. My guess is an oil seal in the turbo was leaking and finally let go. It sounded to me like the engine blew; at any rate it was turning so fast I'd never trust it unless it was completely rebuilt.

Hope the thing was still under warranty.

The way a diesel works is when its not running its in wide open throttle. Then when you start the engine the injector pump governor brings the engine down to idle speed.
 

cpurvis

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The truck was idling when the engine took off on its own. The owner was sitting in the truck and immediately shut off the key but that had no effect. The owner told me he'd just gotten it back from the dealer after being in the shop for a high oil consumption problem.
 

reynoldston

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No way to stop it unless you can shut off the air intake. Sitting in a parking lot with no tools get away from it and let it go I guess unless you a block off the air cleaner intake some how.
 

cpurvis

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No way to stop it unless you can shut off the air intake. Sitting in a parking lot with no tools get away from it and let it go I guess unless you a block off the air cleaner intake some how.

That's right. The old Detroit Diesels had an emergency shut off that blocked the air intake but I've never seen a 4-cycle diesel that had one.
 
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