Immobilising a diesel - how?? - Dave_TD
Hi guys (and gals), I'm hoping someone has an easy answer to this one...

Assuming someone has got hold of the spare key to my car (01Y Octavia 1.9SDi, transponder immobiliser), how can I immobilise it so they still can't take it away? Is there an easy option, similar to removing the rotor arm on a petrol car? It's only going to be an issue til after the weekend, so I'm looking for something to unplug rather than something requiring any tools or lots of time. And I can't guarantee to be able to block it in when I'm not working.

All help appreciated!

Immobilising a diesel - how?? - John Davis
I have pondered on this too. I suppose the obvious one is a key operated switch on the battery supply but, the scumbags would probably be able to bypass this quite easily. Is there a lockable, fuel line valve available which might be more difficult to bypass?
Immobilising a diesel - how?? - Rich Mixture

Is there a fuel cut-off solenoid that you can disconnect? Not sure about your Octavia, but some diesels use a solenoid to block fuel flow to the injectors when the solenoid is not energised (this is why the engine stops when you cut the ignition). On a Citroen BX I once had the rubber plunger (the one that the solenoid drops down onto when you switch off) perish and couldn't kill the engine! Can you disconnect it so that it's never energised?

I'm sure someone will be along in a mo with a better idea however...

Immobilising a diesel - how?? - puntoo
Get whatcar mag for October 2002, they tested crooklock type devices, for about 200 quid you can get a device fitted that locks the gearbox in reverse. For 60 quid you can get a disklock from halfords which they couldn't get past either.

I also remember that you can get an isolating switch/key for the battery, but that would be easy to bypass.

I wouldn't try removing rotor arms or messing with the engine because someone will eventually spot what you are doing or you will knacker out the component that you remove from the engine.

Immobilising a diesel - how?? - Dynamic Dave
Simplest way is to put a relay across the earth connection of the fuel pump and either have a concealed on/off switch hidden under the dash, or a key switch located inside the glove box that you can switch the relay on/off.
Immobilising a diesel - how?? - Dynamic Dave
Sorry, I'm being a right prat. You don't need to add another relay; just find and use the existing fuel pump relay, and put a switch across the earth of that.
Immobilising a diesel - how?? - 659FBE
Dave, Don't mess around with the transponder immobiliser - you may well regret it. The simplest way to immobilise your car on a temporary basis is to find the manual shutoff lever on the fuel pump (between the pump and the engine on a Bosch VE type) and jam it in the stop position with a small piece of wood which the average thick car thief will not see. This will work without any possible damage. Another way is to slightly loosen the fuel input line, either at the pump or at the output of the filter. When started, the pump will draw in air and the engin will stop. You would need to vent the fuel system afterwards, though.
(Ex Lucas CAV employee).
Immobilising a diesel - how?? - bertj
Find the fuse box - I think its at the extreme right or left hand side of the facia. You have to prise the cover off with the door open. Look at owner's manual and find any fuse that says something about fuel or engine. Pull each fuse out in turn until you find the one that prevents the engine starting.
I used to have an Octavia but I can't remember exactly how to do this but I remember doing it!
I did think of breakinto the wire to this fuse and inserting a switch into the circuit to make a 'secret' immobiliser.
Best of luck
Immobilising a diesel - how?? - Dave_TD
Cheers guys, have whipped out the relevant fuse for now, and pushed car into space so you can't open the door wide enough to reach the fusebox...

I should add that it's one of our courier drivers who has whipped the spare key, I leave it in the office in case my car needs moving while I'm out in a lorry. I think I've upset him, he won't do anything stupid with it but he's the kind of prat who would move it for a laugh. I'll get it back Monday morning.
Immobilising a diesel - how?? - puntoo
You could have just hidden the car. or taken the one of the wheels off and removed the spare.

Immobilising a diesel - how?? - Dave_TD
Like I wanna be putting wheels on it at 7.00am tomorrow morning...
Immobilising a diesel - how?? - Richard Turpin
I always remove the fuel pump fuse when going on holiday etc. (Petrol BMW but same theory)
Immobilising a diesel - how?? - Dave_TD
Ah, mechanical fuel lift pump here, sorry...
No trouble with the skoda disappearing yet, just removed the fuse from the "engine control" position, seems to do the trick.
Maybe I should wire a hidden switch in sometime though, in case this happens again?

Value my car