Petrol into a diesel car

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hcockerill | 18:06 Sat 22nd Oct 2005 | How it Works
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I have a golf and have just filled up a tank with petrol, the AA have towed me home, but there is no garage open to do anything about it. I have been told to syphone it out will cost about �180. Any ideas on a cheaper way. Any advice welcome.


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Hi, first question is did you run the engine after filling up?  if you did and its an older car 180 is not bad because it will involve draining all the fuel system inc the pump and fuel lines  etc....etc.... and if the fuel system is not damaged then you got off lightly.

If you ran it and its a newish car be prepared for a very expensive shock.

Obviously if you knew how to drain the tank yourself you would not ask this question so I suppose you will just have to get a garage to do it for you. 

If thats all it is going to cost - go for it. A fortnight ago a bloke at work put petrol in a diesel ford focus. Drove car for a little bit, then it spluttered to a holt. RAC man come and towed him to local Ford garage. Just got it back on Friday with a bill just over �2000! 

you can syphon it yourself with a tube. just suck the end till it starts coming up the tube and come out.

to get the dregs you could put rags in to soak it up. My friend used a hoover once. was messy and hard to clean afterwards though, but they managed it - cheaper than �180. If you try the hoover thing put the paper bag into a plastic bag inside the machine - it gets soggy. and gaffer tape a piece of hose to the nozzle to get all round the tank

i'm not sure if this could be dangerous though !!!!!!

Joko you were joking right!!!  Please say you were joking!!!! and anyway lots of cars have a mesh in the filler pipe to stop exactly this type of procedure being carried out when you are NOT looking,  that is to stop fuel theft. 

no joke qapmoc, thats what my friend did!

Well thats what he said anyway!

It was along time ago though, and on very old car, and perhaps he just got lucky that it worked - and didn't blow him up!

It sounded dodgy to me too, thats why i gave the warning.

Don't think i'd try it myself

Just a few pointers.  If you have a cat exhaust unburnt fuel of whichever type will damage the cat.  It is almost impossible nowadays to syphon fuel out of the tank.

If you have not run the engine you have the option of disconnecting the fuel feed after the pump, put the outlet pipe into a (big) container, switch on the ignition and let the pump do the work until the tank is empty.  Put some diesel in your tank and turn the engine over till it starts.

Howver, I wouldn't recommend this as a garage would also (hopefully) bleed your injectors/pipes and/or turbo to remove the last of the petrol.

Good luck.

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my dad put petrol in his Diesel  Saxo in 1998  2000 miles on clock did it again at 23,000miles the Saxo has now done 134,000 miles.  He just filled it up with diesel,  at both  times  he only put one third of a tank of petrol in.   He says before this new diesel he put petrol in diesel in the winter to stop it waxing up
Hi devilbliss,  well your dad was lucky then,  read this article to see why vvhy ring/2005/08/27/mfdies27.xml
Stupid keyboard! why why I have trouble I don't know
syphone the fuel yourself. Get a garden hose and stick it into the gas tank and start sucking on the other end of said hose. once the fuel touches you lips quickly stick that end into a bucket. Be sure that you have the bucket before you start the process and make sure the bucket is large enough to hold the contents of your fuel tank. The fuel will keep flowing out of the tank until you raise the hose higher than the gas door or obviously when nothing is left in the tank.
i did the same with my diesel clio put in 5 gallons with one gallon still left. drove alright until the petrol got in Your best bet is not to start the car at all as the more petrol that goes through the more likely the injectors and fuel pump will need to be removed... most modern cars have a device fitted which wont allow you to get a tube in to suck out the fuel and RAC advised me to drain a tank they need a licence your best bet is to take it to a garage that can do it. Currently my car is with a dealer they have removed the tank completely and sent it off to be cleaned and have replaced the fuel pump and checked the rest of the engine all to th tune of �532..... and a tank of diesel
I did it on my 03 reg Focus. The tank was on empty when I filled up with dreaded unleaded. Green flag wanted to charge me �150 to come out so I had a look for myself. The answer is simple
lots of PET bottles/jerry cans etc
two 4 or 6-pint milk cartons with the side cut out.
17mm open ended spanner
lift the bonnet, locate the fuel filter ( the corner of the engine cmpt nearest steering wheel)
slide back a white clip holding a black hose on
go underneath the car and slide a similar white clip holding a plastic pipe. Petrol should flow into tour milk carton. when full swap cartons and decant fuel into bottles.
when the fuel has drained, put diesel in this time and pour about 1/2 pint down the fuel filter pipe.
slacken an injector nut with 17mm spanner and crank engine over. this bleeds the air out of the system. keep cranking until it starts - you may need jump leads for this.

Good luck and congrats, youve saved �150
I have a Peugeot 307SW (2002). I filled it from empty with Diesel. I stopped as soon as I heard the engine knocking (about 400m). I had it towed (�20) to a local garage where they drained the tank and lines, flushed the engine, installed a new fuel filter and put in �20 of diesel. The total cost was �159... I had read some threads about this potentially costing �1000 - �5000 to repair... my advice is don't drive your car as soon as you realize what you have done, and take it somewhere you can trust. Everything is working fine now.
I thought I'd add my own experience to this because it's up the top of the google listings for this problem and helped me out.

Basically filled the ENTIRE tank with unleaded, started the engine and got as far as the next pump before it cut out. Not sure why it did that as there was still plenty of diesel in the tank - fuel light had only just come on (apparently the diesel stays sitting at the bottom because it's heavier). This turned out to be lucky.

Fortunately my breakdown cover got the car transferred to the dealer for free so then it's a question of whether I get them or a third party to fix it. Started looking into costs by Googling on my phone (found this thread) and was shocked by the potential cost of repair (e.g. �2,000+++).

Spoke to a mate in the know. If I hadn't turned the engine over at all, the official dealer would have charged me about �200 to drain the fuel, flush the system and change the filter, which is reasonable. But because I did turn the engine, they would be able to tell the engine had been compromised. They would tell this after draining the fuel, and would go on to charge for replacing all the parts involved in the fuel system as well. Bottom line is that once the dealer has it in their garage and prove the engine is 'damaged' they have you over a barrel.

Three reasons why I didn't have this problem:
- The car didn't get very far (AA bloke said it was tantamount to not having started it)
- It's petrol in a diesel (not so bad)
- There was a decent bit of diesel left in the tank (so it may not have been pure petrol that got pumped through).

So instead I got quoted �170 by the AA to tow the car out of the dealership and perform the draining procedure. It worked. I think I got off lightly considering what could have happened.
Petrol in Diesel
Do not turn on the ignition or start the car

If the car's still under warranty check with the franchised dealer regarding their advice and correct remedial action – running with even a small amount of petrol in the tank might invalidate the warranty. Some manufacturers advise that you should get seals and filters renewed even if the engine has not been run.

Generally a small amount of incorrect fuel should not damage the engine as long as you have not started the car and top up fully with diesel.

If you've added more than 5 litres of petrol – Drain the tank and refill with diesel
If you've added less than 5 litres of petrol – Top up with diesel and run normally unless the manufacturer has advised otherwise
Diesel in Petrol
Do not turn on the ignition or start the car

This is less common because the standard diesel nozzle is bigger than the filler neck on modern petrol cars – you have to be pretty determined and patient to misfuel with diesel.

If the car is still under warranty check with the franchised dealer regarding their advice and the correct remedial action.

Generally a small amount of incorrect fuel should not damage the engine as long as you have not started the car top up fully with petrol.

If you've added more than 5 litres of diesel – Get the tank drained and don't run the engine.
If you've added less than 5 litres of diesel – the tank can be topped up with petrol and the car run normally unless the manufacturer has advised otherwise

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Petrol into a diesel car

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