Engine keeps running

wolfe10 wrote:


Inline shut-off valve-- never seen one on that chassis, but a VERY good idea on the inlet side of the primary fuel filter.


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Our Cat had one. And yes we had to use it.

I don't have this issue but I'm prepared for it with a pair of channel lock pliers I can use to crimp the fuel hose closed so it runs out of fuel. The hose is accessible right at the remote water/fuel separator.

That shouldn't hurt anything should it? Naturally, I'd head straight for a shop asap.

My 2006 Cat 350 does this every so often. I have changed the ignition switch, been over every thing I can think of, as has the local Cat shop. I merely turn the engine batteries off. My fuel pump is electric so that kills the engine. Problem hasn’t cropped up for a while. So I don’t know if it’s fixed or ???? Good luck.

For my old 6BT5.9 I have a fuse labeled IGN that'll shut it right down if pulled.

Yea Brett, a turbo diesel can lose a turbo seal and "run away". If it's a big enough leak, it will run well beyond max RPM since the gov. is out of the circuit. Either way, unless you plug the intake, it will run until out of "fuel" and seize.
There are countless videos on Youtube of this happening. Pretty entertaining!

RTCastillo wrote:
Use the choke!

What choke?

WOW, some really "interesting" replies.

First, suspect this is a Caterpillar 3126 330 HP.

Choke??? on a diesel??

EGR cool down time on a Caterpillar 3126???

Engine is toast because of a (possible) turbo oil seal leak?????

Inline shut-off valve-- never seen one on that chassis, but a VERY good idea on the inlet side of the primary fuel filter.


Let's start with the BASICS:

Are the dash gauges still active/Allison shift pad still illuminated? If so, that points to a failure of the IGNITION SOLENOID or IGNITION SWITCH.

Please give us more facts on exactly what is working as usual vs what is different when you turn off the key.

naturist wrote:
Yup. You don't want to hear about the OTHER possible failure (because a leaking turbo oil seal usually means the entire engine is toast).

That's scary. If the engine is toast, wouldn't it seize? Or does it lock up when it finally stops running?

Usually there is an inline valve to shut off the fuel supply. Could need a flat head / straight slot screwdriver to turn it. As mentioned. diesels don't need electricity to run. It will run until it runs out of fuel.

I have an egr cool down timer on my Ford 6.0 diesel that keeps it running for a bit after I shut down. Could you have something like that?