I may have put petrol in my 1.9 TDI Octavia (2004) diesel on Friday morning. It had about 1/8 tank of diesel and I stuck about half a tank in. Can't honestly remember if it was unleaded I put in. I drove it to and from work (about 8 miles) and sat it on the drive until Sunday. When I tried it it was dead, engine ticking over but not firing. Gave it a few goes and eventually got it going with some heavy gas but with blue smoke chugging out of the exhaust and the engine juddering. Now, I've read allsorts about it potentially being the injectors, pistons, various seals and gaskets but I've no idea how to diagnose these things. No engine management light on.

I was hoping someone might have a clue what is going on from the symptoms? If I'd stuck that amount of unleaded in, would it have driven at all? Would you expect blue smoke to be expelled? If so, can anyone tell me how to drain the tank as I'd prefer to have a go and rule this idiocy out for myself before I let a garage at it.

Cheers for any assistance

I seem to recall that one of the motoring magazines admitted that one of their drivers had filled up a diesel Ford with petrol and got away with it, and had never ever noticed a problem. So you might want to run a risk - fill up fully with diesel, go for a reasonably long run, and hope that the various seals/injectors have not been damaged. That of course is my personal view, and if you take me up on it my usual lawyers (Messrs Sue, Grabbitt & Runne) will be on your case.

I may have put petrol in my 1.9 TDI Octavia (2004) diesel on Friday morning. It had about 1/8 tank of diesel and I stuck about half a tank in. Can't honestly remember if it was unleaded I put in. I drove it to and from work (about 8 miles) and sat it on the drive until Sunday. When I tried it it was dead, engine ticking over but not firing. Gave it a few goes and eventually got it going with some heavy gas but with blue smoke chugging out of the exhaust and the engine juddering. Now, I've read allsorts about it potentially being the injectors, pistons, various seals and gaskets but I've no idea how to diagnose these things. No engine management light on.

I was hoping someone might have a clue what is going on from the symptoms? If I'd stuck that amount of unleaded in, would it have driven at all? Would you expect blue smoke to be expelled? If so, can anyone tell me how to drain the tank as I'd prefer to have a go and rule this idiocy out for myself before I let a garage at it.

Cheers for any assistance

I may have put petrol in my 1.9 TDI Octavia (2004) diesel on Friday morning. It had about 1/8 tank of diesel and I stuck about half a tank in. Can't honestly remember if it was unleaded I put in. I drove it to and from work (about 8 miles) and sat it on the drive until Sunday. When I tried it it was dead, engine ticking over but not firing. Gave it a few goes and eventually got it going with some heavy gas but with blue smoke chugging out of the exhaust and the engine juddering. Now, I've read allsorts about it potentially being the injectors, pistons, various seals and gaskets but I've no idea how to diagnose these things. No engine management light on.

I was hoping someone might have a clue what is going on from the symptoms? If I'd stuck that amount of unleaded in, would it have driven at all? Would you expect blue smoke to be expelled? If so, can anyone tell me how to drain the tank as I'd prefer to have a go and rule this idiocy out for myself before I let a garage at it.

Cheers for any assistance

my lass put £10 worth of petrol in hers mates diesel (it was empty) so filled it to the brim with diesel and got away with no major issues just a bit of smoke (it was a turbo diesel mondeo) i would try as mentioned fill to the brim with diesel and go for a long run to hopefully clear it out

Edited 30 March, 201016 yr by sivrs

I did the same thing about 2 years ago but I had only gone about 3 miles when I realised what I had done when the engine sounded rough.I calle my break down and had it towed to my local Nissan dealer. They cleaned it out and changed a couple of filters and it was OK. No long term effects, but i cost about £160 for labour and parts. I believe it is more drastic if you put diesel in a petrol engine.I would not run it any more until it is cleaned out at least.

Best of luck Bob Wilson

I didnt think leaded petrol was sold anymore.

So you ended up with a diesel : petrol ratio of 1:3.

Personally I would empty the fuel tank and refill with diesel, change fuel filter and run the engine. Dump the waste fuel in your oil central heating tank if you run oil ( a few litres of petrol in amongst 1000s of heating oil will have no effect) or take it to your council recycling centre. If its knackered the fuel system then there is nothing you can do anyway so you might as well try this and keep fingers crossed.

As I understand it modern diesels use the diesel fuel for lubrication of PD injectors and CR pumps. As very high pressures are involved lack of lubrication can cause expensive damage. Older cam belt injection pump diesels were much less affected. However you can be lucky and get away without trouble.

if you really have put that much petrol in, you need to get it out. can you smell petrol at the filler neck? check the receipt?

when i misfuelled my old TDI90, i attached an old aircooled VW fuel pump to the feed from the tank to the filter. new filter in too. sucked out the petrol from the injector circuit with a mityvac as well. have to admit, i've done it twice, and the missus has done it once in her PD. so in my case at least, that is "definite idiocy" :(

Edited 30 March, 201016 yr by redlemon

My dad done this in his 218D and also when he borrowed my 418D.

Both times it was 5 quid before he relised what he had done, and the rest of the tank was filled with diesel but cars were fine. But I would not be tempted to do the same in a newier diesel engine, I'd drain it and not take the chance.

I have done it the other way round on another car, put BP Ultimate diesel in instead of BP Ultimate petrol. Bloody daft the way they put the same colour scheme on both pumps but still felt a complete nob. Cost me £130, £75 labour plus £55 wasted diesel . . . :-(

Cheers for the responses, most appreciated. I think I'll take the financial hit and get a garage to drain it and hope it doesn't need any engine parts replacing. I'm hoping that because it is a PD rather than one of these new fangled common rail jobbies the bit of driving I've done in it won't have done any lasting damage. Does anyone know if the blue smoke is a likely symptom of running a diesel engine on petrol? Also, I'll have a sniff of the filler - does Diesel actually have a smell? If not and I can smell petrol I guess I have my answer. Unfortunately I've not got the receipt (looked high and low for it).

I think you would be very wise to get the tank cleaned out and all the fuel lines cleaned and filters replaced. Though to be honest you have will probably already done damage to the engine because of the lack of lubrication ( I believe its the fuel injectors that will fail from misfuelling and these are not cheap) by driving it around with petrol in (if in fact you have put unleaded in). I have a constant worry about doing this (having a petrol Toyota and a Diesel Octavia) so I invested in a misfuelling prevention device - costs about 30 quid and is well worth it.

http://www.stopdieselmisfuelling.co.uk/

It's a doddle to fit and use ( not too fond of the colour though I suppose it's that bright for a reason).

I think you would be very wise to get the tank cleaned out and all the fuel lines cleaned and filters replaced. Though to be honest you have will probably already done damage to the engine because of the lack of lubrication ( I believe its the fuel injectors that will fail from misfuelling and these are not cheap) by driving it around with petrol in (if in fact you have put unleaded in). I have a constant worry about doing this (having a petrol Toyota and a Diesel Octavia) so I invested in a misfuelling prevention device - costs about 30 quid and is well worth it.

http://www.stopdieselmisfuelling.co.uk/

It's a doddle to fit and use ( not too fond of the colour though I suppose it's that bright for a reason).

I have put unleaded in it as I have just found my receipt. Embarrassed but at least I know what is wrong with it. From my reading I know I'm looking at at least £200 for a drain and a bit of a clean plus a refuel on top. I take it if I have done pretty much any serious damage to the engine I'm looking at a repair bill in four figures? Hopefully it ran on diesel for the few miles I drove it and only a bit of petrol has got into the engine.

If I get away with it I will be buying a misfuelling device, no question about that.

I may have put petrol in my 1.9 TDI Octavia (2004) diesel on Friday morning. It had about 1/8 tank of diesel and I stuck about half a tank in. Can't honestly remember if it was unleaded I put in. I drove it to and from work (about 8 miles) and sat it on the drive until Sunday. When I tried it it was dead, engine ticking over but not firing. Gave it a few goes and eventually got it going with some heavy gas but with blue smoke chugging out of the exhaust and the engine juddering. Now, I've read allsorts about it potentially being the injectors, pistons, various seals and gaskets but I've no idea how to diagnose these things. No engine management light on.

I was hoping someone might have a clue what is going on from the symptoms? If I'd stuck that amount of unleaded in, would it have driven at all? Would you expect blue smoke to be expelled? If so, can anyone tell me how to drain the tank as I'd prefer to have a go and rule this idiocy out for myself before I let a garage at it.

Cheers for any assistance

Syphon out as much petrol as you can and re-fill with diesel and you should not experience any problems. Don't take it to a garage as they will charge you a fortune to drain the tank and replace the filters. If it was diesel into a petrol then you would be knackered.

In most cases when PD diesel Octavias are filled with petrol, they start and the driver drives until the engine stops. Driver calls tow-truck, garage sucks out bad fuel, replaces fuel filter and flushes fuel lines, no harm done.. I work at a Skoda dealer, and I still haven't seen any problems that could be related to the filling of petrol earlier in the cars life.

Have the tank drained, fuel lines flushed, new fuel filter, full tank of fresh diesel, and you are good to go

The blue smoke is a result of bad combustion/misfiring because of the petrol/diesel mix..

Maybe you should consider one of theese in the future? : My link

:yes:

In most cases when PD diesel Octavias are filled with petrol, they start and the driver drives until the engine stops. Driver calls tow-truck, garage sucks out bad fuel, replaces fuel filter and flushes fuel lines, no harm done.. I work at a Skoda dealer, and I still haven't seen any problems that could be related to the filling of petrol earlier in the cars life.

Have the tank drained, fuel lines flushed, new fuel filter, full tank of fresh diesel, and you are good to go

The blue smoke is a result of bad combustion/misfiring because of the petrol/diesel mix..

Maybe you should consider one of theese in the future? : My link

:yes:

Thanks Jon, I will be taking your advice on this, appreciate it is going to cost me a few quid but now quite reassured that it won't run into silly money. Cheers to everyone for their advice.

My dad done this in his 218D and also when he borrowed my 418D.

Both times it was 5 quid before he relised what he had done, and the rest of the tank was filled with diesel but cars were fine. But I would not be tempted to do the same in a newier diesel engine, I'd drain it and not take the chance.

The XUD engine found in the rover *18D cars was fine to run on a bit of petrol in the derv in winter, it was advocated to prevent waxing.

On some models there was a fuel heater system on the engine, which was a series of pipes that the diesel fuel a few inches above the some warm components at the back of the engine IIRC.

About 12 months ago I put 40 litres of petrol in my 2007 Passat 170 TDI. Ran about 2 miles and engine stopped. Called AA. Advice was that if I had the car taken to a VW dealer, they would replace the pump and ancillaries and the bill would be in the region of £2k.

The AA man said he'd never seen a VW engine wrecked by petrol in tank other than when travelling at high speed on motorway after a service area fill up.

He suggested taking my car to a local garage and having them simply empty the tank which is what I did. It cost me £170 and the cost of the diesel but 15k miles later I've had no problems.

The problem was said to be that as diesel injection pumps are usually lubricated by the diesl fuel, petrol washes this out.

However a discussion on the Yeti section about the relative merits of the PD and CR diesels suggests that in the PD engine, the pump is lubricated by engine oil which suggests that the lubrication issue is not a problem.

Good luck.

John