Hi

I put petrol in a 1.9 TDi on Monday. I didn't start it and was towed to the garage and the tank was drained. It started fine and I've driven 100 odd miles since. The problem is that as the revs increase around 3000 the engine stutters. Is something broken, is it an air lock or maybe a blocked filter ? Has anyone else made the same mistake and experienced a similar problem. Thanks in advance for any advice.

Skody

How much petrol, and how much diesel was left in the car when you filled up.

Interesting article in newspaper a couple of days ago - comparison of what happens [cost wise] when wrong fuel goes in and how garages rip off owners with exaggerated claims of cost of putting things right.

Would you believe Skoda came out best, for draining off, flushing, new filter etc. Still 3 figures though, bit over £100 I think. Owners of "posh" cars were being charged 4 figures in some cases.

As the tank was drained before you started it there should have been minimal petrol left in the system so no serious damage to the fuel system should have occurred, if the garage did a proper job.

Did the garage fill you with fresh diesel, flush the fuel lines and fit a new fuel filter, before starting the car, if they did you should be OK after a few days/couple of hundred miles to flush any minute drops of petrol from the system. If stuttering continues then all that should be required is another new fuel filter.

If they did not flush the fuel lines get a new fuel filter fitted straight away and ask them why not - if they left petrol in the fuel lines then the injectors might have been damaged and if so you could have a claim against them for not doing their job properly.

I have to admit that I did this in my previous car - Mk1 1.9tdi octy.

I didn't realise till it conked out:eek:

tank was drain, lines flushed and new filter - ran perfectly after that.

The general concensus of opinion with various motor magazines that have done reports on this very problem is that the 1.9 Tdi enginge is about the most forgiving diesel engine. Even the Skoda Assist man I know says that even if they are run with petrol in them they almost always recover perfectly!

What about the newer 2.0 diesels?

The main reason I moved from Citroen HDi to Skoda PD was the above regarding petrol in diesel.

There are horror stories on the French car forum and the Ford diesels have a poor repution of reliability if petrol is accidentally used.

The reason seems to be that the common rail pump has to be made to very very close tolerances and uses the fuel as a lubricant. Petrol isn't a lubricant and I guess that the seals might not like it either. The pump doesn't show problems until some time later.

This is not so much of a problem when buying new as you know what you are doing ------ ? Buy secondhand though and who knows.

A couple of years ago a friend filled his Renault Laguna diesel with petrol, he did not start the car and had it towed home. he pumped the fuel from the tank(under the rear seat cover) and put a five litres of diesel in and it started OK. He drove about a quarter of a mile to the petrol station and filled with diesel. There was a little bit of smoke for a couple of miles, but after that the car was fine. As you didn't start the car I wouldn't have thought any petrol had entered the system. So how good a job did the garage do in draining the tank?

Missfire at 3000 ish RPM sounds like a faulty lift pump to me but also can be a blocked fuel filter. But really they should have replaced that anyhow after the wrong fuel is used.

Help ! - Wish to continue the use of this thread - because I have also just put about 15 litres of petrol into a tank containing about 30 litres of diesel !http://briskoda.net/images/smilies/frown.gif

Having , recently bought I diesel , I had been obsessive about this but ,got thrown by a different garage , colour of pump / hose .... you all know the excuses .

Realised ,before starting the engine , a 2008 PD Scout , and rang Skoda Assistance - they called the RAC out - we were about a 75 miles from home on a Saturday evening . They arrived , called out a flatbed truck from a local garage who took the car away and then drained the fuel .

Well up until the last quarter of the tank . Then they tried siphoning from the fuel filter pipe and a couple of hours later with more technicians on the scene they eventually said that all was sorted , filled it up with diesel and we arrived home into the wilds of Wales well after midnight .

However in the cold light of day I am suddenly faced with the dilemma of what to do next , for the garage did not know that there was a W shaped petrol tank and I am now very suspicious that they did/could not drain all of the fuel out . The garage was also very vague about how much diesel they put into the car .

The car ran faultlessly back home , and I wonder whether this was because , if I read the excellent diagram provided earlier correctly -

The fuel tank away from the filler pipe was already full of diesel before the incident and I largely put petrol into the nearer tank , which was the one that the garage was able to drain . The 10 litres of fuel that I used on my journey home was taken from the nearer tank , which contained the newest diesel that I filled the car with after the event ???

Having read the literature I have the following options -

Take the car to Skoda to drain both tanks - although even the RAC suggested by the roadside that this was not a wise option because of future warranty problems and a bill of £ 3000 , and indeed is it now too late ?

Keep topping up the tank with diesel , working on the " dilution " solution ?

Use a lubricant additive , as well as the above ?

I appeal to you all for any advice ?

It won't help you now as you've already done it but the last thing to do is call Skoda Assistance, if the car is taken to a dealer they'll record this on your car's file and then may refuse warranty claims on fuel related items in the future.

If I were you I'd just keep running it and dilute what was in the tank.

You will have absolutley nothing to worry about, the car wasnt started and the mixture was diluted enough to mean there was minimal petrol in there anyway.

Remember that in winter truckers used put up to 25% of petrol in there tanks to stop the diesel from freezing.

Steve

Usually we use the intank lift pump drain out the tank anyhow so that should have got it all out anyway.

I see you are in North Wales, hopefully you didn't have to wait too long for the RAC, from past experience it takes between 3.5 and 4.5hrs to reach me in north wales

I'm a diesel fuel technologist. So long as you don't start the engine, drain the tank as well as possible and then FILL UP with diesel, there should be no damage to the engine. The only issues arise if you start the engine after filling with petrol;

1) Diesel fuel contains a lubricity additve. This is for the fuel pump, as correctly stated by someone earlier on. Petrol does not lubricate the pump, so running a slug of petrol through it can strip all the lubricant and you risk damaging it. A new fuel pump could set you back £2000, so not recommended! Truck engines have much cruder lift pumps without the fine tolerances, so you can get away with putting a bit of petrol in when it's cold to stop the filter waxing. Petrol will not cause the filter to block, or damage it in any way.

2) Petrol has much higher vapour pressure than diesel. If you have enough of it in the fuel, you run the risk of cavitation in the fuel lines (AKA voids or "air locks"). This won't seriously damage the engine, but it may make it run lumpily, or not at all.

3) Petrol has a much lower flash point than diesel. It's meant to be ignited with a spark, and it won't ignite under compression like diesel. Result: lots of smoke, or the engine simply won't start. This won't in itself damage the engine, although if you run it for long enough you may damage the aftertreatment devices (oxygen sensors, oxidation catalyst, DPF if fitted)

4) Petrol is about 15% less dense than diesel. Although completely soluble in diesel, the mixing is far from perfect in a tank. You may well get a long way before you start noticing problems, especially if there was already a significant volume in the tank already (indicently, this difference in density is at least 50% of the increase in MPG you get from a diesel!) Bear this in mind when you drain the tank- the best way is to syphon off from the top, not the bottom.

Hope this helps! I'm sure there are many more issues, but these are the ones that sping to mind.

Been there done that. Today. Filled the thank with apprx 30 litres of gasoline, when the tank had about 15 litres of diesel. Drove the car away from the pump, 15 meters, and stopped engine.

So how do I drain the tank?

I saw one tip that recommended taking the diesel and return hose off the filter, and by using compressed air on the fillerside (using some kind gasket to keep the air in the tank), it should be possible to blow the diesel/gasoline mixture out those lines.

Any other tips for doing this?

done this about 6 months ago in a bp garage... :eek:

7 l's of petrol in 130 tdi

thought fack it & filled it up with nother 30 l's of diesel

took it for 100 mile run then filled up tank til full

was a wee bit smoky for a wile

no probs since... here's hoping..

We have just bought a diesel Mazda 5 (& I run a petrol Vrs Octavia myself)...and am absolutely paranoid about this...I checked out all the aftermarket options for creating some kind of 'barrier' to 'doing the wrong thing'...and while there are plenty of options, I went for a £6.99 gadget called the 'Think Diesel'. it sits inside your fuel cap & speaks to you as you open the flap - reminding you it's a diesel. Hopefully it'll be enough to stop me or the missus filling up with petrol. I was a little unsure of fitting a battery type device inside a fuel cap, but it checks out, has had all the required tests & Halfrauds sell it (so don't have to pay the P&P the online folks want).

Think Diesel - Think Diesel - Petrol Misfuel device

I appreciate it doesn't help those that have already done it...but it may save some of you a great deal of grief !

It depends how the tank was drained "skody" , some garages use a vacuum device which sucks the fuel out of the tank through the filer neck,in this case the pipes are not flushed out , even if the car is not started petrol will migrate up the pipes,the other way it is done is to disconnect the fuel pipes from the filter and pump and ether suck the fuel out ,or using a device attached to the obd socet continuasley run the pump in the tank and pump it out ,but its impossible to get every drop out ,

for info the aa will drain your tank and add fuel to get it running for £180 and this can be done any where even on the garage for court and to none members.