Skoda Octavia - engine not turning off

[HarryHornby]

Hi Foccer font of all knowledge.  We've got a weird one on our 04 reg Skoda Octavia. 1.9 turbo diesel


Car was unlocked this morning and when the wife and kids got in the dashboard lights (battery etc) were on before the key was in the ignition.  Apparently it took a couple of goes to unlock too (remote key fob)


Did the school run, all ok.  Got home, turned off ignition, pulled out key, engine kept going.  Normal revs, just as though the ignition was on.


Told the wife to stall it, she couldn't go forward so put it in reverse.  As soon as reverse was selected the engine stopped.


It's done it on and off all day, keeping going more than it's stopping when it should.


I've put a very basic engine fault finder thing on the engine management socket in the car and it came back with no errors.


I've just gone out to the car and started it up, it' was a little sluggish for about 20 seconds upon starting then reved fine, a not normal shooshing noise (not loud) coming from under the bonnet.  This stopped when the car revved fine.


Turned off ignition but car kept going.  Engaged reverse and it instantly stopped.


I've read about diesels overrunning and blowing themselves up due to oil leaking from the turbo but it's not that I am sure, revs are fine, no white smoke.


I'm guessing electrical...... strange how when reverse is engaged it stops the engine normally, I wonder if the turning on of the reversing lights is doing something?


My other thought is fuel pump?  Diesels stop by stopping the fuel pump, correct?  Maybe fuel pump not cutting out?

Battery??

Any ideas lads.


PS if you've read this far you deserve a medal!   

[Frosties]

I'd be leaning towards water ingress following recent weather playing havoc with the circuits. Does the car smell of damp? Damp footwell? Does the boot smell of water ingress?


Even though a diesel will happily run on an oil leakage from the turbo - would such a leak be sufficient to sustain the engine ?? I doubt it but would check engine oil level anyway. Keep us posted fella.

[Skippernick]

I reckon electrical.
I've had 2 boat diesels start to run on its own oil, trust me you'll know its fucking scary, only way to stop it if you have the balls is to block the air filter, but not with your hand as it might take the skin off!


Off to the garage me thinks.

[HarryHornby]

Oh, I forgot to say I thought it was water playing havoc with electrics, the car is dry inside.  I had the bonnet up this evening (in the dark) and had a look around with the torch but couldn't see anything indicating excess wet.


I checked gutters under the bonnet and all seemed ok.


Checked fuses within the car and they were dry.



I had read about screenwash pipes popping off when frozen (we had that several years ago and had a big puddle in the boot) both front and rear screenwash are fully powered and there doesn't appear to be a leak.

[Frosties]

How many fuse boxes do you have and where are they? Any junction boxes?


You know full well if you have the garage look at it it'll be a case of "well it didn't do when we had it - that'll be £200 please"

[HarryHornby]

Ah, Mr Frosties, you are wong there.  Wife took it to Sittingbourne Halfords Autocentre (they've had it before and have always seemed very honest).  They test drove it, didn't get the fault, gave it back no charge.    ALTHOUGH, I'm still worried about a big bill now that they will have to start having a proper look.  Electrical faults could be a long repair time, and that's just to find them. 

[joebloggs]

Not a clue about your problem, does sound electrical but lets face it it could be a 101 different things causing you grief. One thing I would check though re water ingress, is drain holes in and around the scuttle area.

[HarryHornby]

Joe, when you mean scuttle holes, is that the drain points under the bonnet around the bottom of the windscreen area (back of engine bay)?


I'm wondering if it's worth leaving it a couple of days before taking it to the garage.  Give it a good run when I get back from work this evening to get some warmth under the bonnet.


Am worried if I take it back to the garage they will spend ages tracing something they can't find and I'll get a big bill and nothing to show for it.

[red98]

sounds like electrics to me...as always check the easy things first, battery,earths etc .......iam a skoda owner and member of the BRISKODA forum....very good forum,think FOCU for skodas  ....get logged on and i`ll look out for you.....the only down side is you`ll find FOCU legend  NOGGYTHENOG on there            

[Freck]

Some diesels have a shut off valve, bit like a decompression system to stop the engine.
Problem is that diesels are self perpetuating in a way as they rely on compression to make combustion, so breaking that compression cycle will stop the engine.
I'm wondering if yours has such a system that's not working properly.
It should stop itself eventually but only after the high pressure in the fuel lines had depleted.

[HarryHornby]

That makes sense, but why would the action of putting it in reverse (and not disengaging the clutch) stop the engine as per normal?  Looking more and more like a pesky electrical problem.

[BBROWN1664]

If it was running on it's own oil, it would be smoking like a steam train and revving its nuts off until it went bang.

This sounds like the master relay (or whatever they call it on Skoda) not unlatching when the ignition goes off. This is keeping all the electrical circuits live and letting it run on.

Give all the relays a bang (the ones under the bonnet are the most likely culprits)

[Skippernick]

That makes sense, but why would the action of putting it in reverse (and not disengaging the clutch) stop the engine as per normal?  Looking more and more like a pesky electrical problem.

Does it do it if you put it 1st or is it just reverse?

[noggythenog]

sounds like electrics to me...as always check the easy things first, battery,earths etc .......iam a skoda owner and member of the BRISKODA forum....very good forum,think FOCU for skodas  ....get logged on and i`ll look out for you.....the only down side is you`ll find FOCU legend  NOGGYTHENOG on there            

Only thing is my little skoda is so reliable i rarely go there .......20k miles hassle free which is rare these days.......but skoda are on my answer machine this very afternoon........oh dear .......but briskoda is the place to go they seem really knowledgable, have skoda sponsors and mechanics and allot of members.




One more shout out for the amazing skoda fabia 1.2TSI 105 

[HarryHornby]

That makes sense, but why would the action of putting it in reverse (and not disengaging the clutch) stop the engine as per normal?  Looking more and more like a pesky electrical problem.

Does it do it if you put it 1st or is it just reverse?

Just reverse.  Just the action of putting it into gear, not even trying to move the car.

[Frosties]

That makes sense, but why would the action of putting it in reverse (and not disengaging the clutch) stop the engine as per normal?  Looking more and more like a pesky electrical problem.

Does it do it if you put it 1st or is it just reverse?

Just reverse.  Just the action of putting it into gear, not even trying to move the car.

Humour me on this one Harry - can you remove the reversing bulbs and try it again (may indicate an earthing issue).

[joebloggs]

Joe, when you mean scuttle holes, is that the drain points under the bonnet around the bottom of the windscreen area (back of engine bay)?


I'm wondering if it's worth leaving it a couple of days before taking it to the garage.  Give it a good run when I get back from work this evening to get some warmth under the bonnet.


Am worried if I take it back to the garage they will spend ages tracing something they can't find and I'll get a big bill and nothing to show for it.

Yes. It can cause issues if they've bolted electrics to the bulkhead or like my eunos in the footwall. Worth keeping it leaf free either way.

+1 on the taking it for a good run option. Brother had an Astra with a cutting out fault. Cost several hundred £ to find foc all

[unfazed]

This is from memory and cannot remember if it was an Octavia or a Superb, but had a similar problem.
Check the left side of the boot around the wheel arch (you will need to pull of the panel to look in) and see if the rear window washer pipe has come adrift and soaked the wires near one of the main earths. Drain the water out, there might be a bung and dry everything off.
Kind of ties in with the reverse lights and it may just be a loose connector which is also in the same area.
 
If you have access to an OBD reader  it would help locate the issue also.

[Robbie8666]

If you have access to an OBD reader  it would help locate the issue also.

I've put a very basic engine fault finder thing on the engine management socket in the car and it came back with no errors.

maybe worth taking to a garage to see if they can find a fault with proper diagnostics if you cant see any water ingress or obvious electrical problem!


can I just say as a Skoda owner how nice no-one (yet) has slagged skoda's off as they would've done 15 years ago ..... (stands back to now get flamed!! lol)

[joebloggs]

Whats to slag off

[HarryHornby]

FIXED IT!  although we are now £420 lighter!


Took the car to an auto electrician who came very highly recommended by a fair few people.


He found a rotted loom in the back LH corner, which is where the windscreen washer pipe had popped off a couple of years ago, I did dry it, but I suspect not all of it.  He replaced that.  This could explain the act of reverse turning the engine off (shorting out?)


The Central Convenience Module had a fault on it and had caused some burning on some attached wires.  This controls the electric windows, central locking and other bits and bobs, this was what was causing the big drain on the battery.  He replaced that.


He found that the housing around fuse 7 was melted and associated wires were burnt too.  replaced.


Apparently, an acceptable drain on a car battery is 0.5amps, he's got ours down to pretty much zero apparently.


SO, fingers crossed, it's all fixed.  Just got to pay the Father in Law back now!   

[stevie-g1968]

check under the plastics in the scuttle area, vw and audis drain holes get blocked with leaves a shite... this the fills up and can do strange things with the electrics... sounds like a ECU fault and if that's going wonky it could stop it showing codes , and also expensive.... get it on a VAG COM reader.. independent vw audi place wont charge the earth to read the codes.

[stevie-g1968]

just ignore me... being a twat and not reading all the posts...