Defender, turn off, remove key, engine still running....

[philcray]

56 plate Td5 Defender, turned off the ignition, removed the key and the engine kept on running...

Happened about 3 times now, so far only when I have a trailer connected so may be affecting the electrics?

The first couple of times I popped the key back in and it kept on running no problem. When it happened on Saturday, I think it just stalled a minute or so after I took the key out.

Any ideas on what might be causing this would be appreciated!

Phil

[HarryW]

I presuming the fuel pump is not running once you've switched it off. It could be Consuming it's own oil? Over filled or loads in the intake being burnt off, either way be careful it doesnt run away and destroy itself...

[anonymous-user]

Definitely sounds electrical if it only happens when a trailer's connected.
TD5 ECUs can act very weird if they start getting spurious voltages through slightly chafed wires or damp plugs.
I'd start by giving the trailer socket a fecking good clean and a blast of drying air if you've got a compressor.
Then maybe look at replacing the trailer socket sub-loom?

[Cliftonite]

Meanwhile, be ready to stall the engine promptly if it 'runs away' with you!

[CAPP0]

Cliftonite said:

Meanwhile, be ready to stall the engine promptly if it 'runs away' with you!

Yes, I'd be very concerned about this, although from my limited knowledge of diesels consuming themselves, I think if it starts then it goes all the way, unless you are able to stall it?

[blueg33]

Defenders have been known to do this

Runaway Defender on youtube

[abbotsmike]

blueg33 said:

Defenders have been known to do this

Runaway Defender on youtube

It's a diesel thing, not a defender thing.

OP, could it be something as simple as a dodgy ignition switch?

[blueg33]

abbotsmike said:

blueg33 said:

Defenders have been known to do this

Runaway Defender on youtube

It's a diesel thing, not a defender thing.

OP, could it be something as simple as a dodgy ignition switch?

I know that! But the vid is of a Defender

[anonymous-user]

I think we may be missing the obvious here....
Given this only happens when you've got a trailer on, what happens if you unplug the trailer whilst this is happening?

[philcray]

Thanks for all the feedback.

The first couple of times it happened, I simply put the key back in and the engine just carried on running as normal, so it looks like it might be connected to the ignition switch rather than the engine running away.

On the next time, I stalled it as I let the clutch out not expecting the engine to be still running(!) and then on Sunday it stalled itself - this may have tied in with the trailer electrics being unplugged as I was still in the car when they were unhitching but I didn't put two & two together at the time.

It has only ever done it with the trailer attached so that does look to be the culprit.

On the positive side, it always starts fine and runs normally after this little quirk has happened....

The car is a 56 plate and has only done 10,000 miles, it had never been used for towing before so it may be dirt on the connector or maybe corrosion? All the lights, indicators etc work correctly on the trailer when connected to the car.

[anonymous-user]

Definitely sounds like the towing electrics, if not the actual trailer itself.
I wouldn't read too much in to the trailer lights working correctly. Often it only needs a slightly random earth or trickle of voltage to the wrong pin to throw the ECU in to a hissy fit.

[Bill]

My D2 started doing this when the lights were on, it went away when I got the main earth cleaned up and the handbrake cable (that had turned itself into an impromptu earth) sorted.

[cpas]

If you connect the trailer up without the key in, do the ignition lights come on on the dash? If so, there's a permanent live contacting an ignition only live somewhere. This was happening on my 200Tdi but was chaffed wiring in the main loom!!