I Accidentally Put Petrol In My Bmw 635D

[Chinoo1]

I own a bmw 635d and about a week ago I accidentally put 18 litres of petrol in it (when it was on reserve) I drove off the forecourt unaware, about a mile later the car start to judder and lose power (I then realised what I done) I made it to the next petrol station about 2 miles down and topped the car up with £50 worth of diesel (full tank) I then started the car and it started to run fine so I carried on my journey home (30 miles) and made it with no problems and since then I done over 100 problem free/smooth miles (filled the car up again in between with premium diesel) apart from sometimes it takes maybe a second or two longer for engine to turn over/start up there don't seem to be any problems with the car. But I'm still worried am I in the safe now? Or shall I start looking to trade the car in before things start going wrong? Help me people! Thanks.

[ummmm]

Have you tried phoning a garage? It sounds like it'll be alright to me after that amount of mileage. Maybe you just didn't notice the second or two before this mistake.

[Buenchico]

Putting petrol into a diesel engine (and then running it) is unlikely to do any long term damage. (It's the other way round that can cost you a new engine!). It will be fine.

[1ozzy]

http://www.rac.co.uk/breakdown-cover/wrong-fuel-recovery/petrol-in-a-diesel-car

[Buenchico]

Hmmm.

While 1ozzy's link, is of course, accurate as to the theoretical risks of misfuelling, I have to doubt whether it's actually relevant here. That's because:
(a) people put all sorts of things into their diesel tanks (such as used cooking oil) and get away with it ; and
(b) there's probably not much point pumping the fuel out now, as most of the petrol has already gone through the system anyway. (However it might be worth topping the tank up again with diesel, at more frequent intervals than usual, to dilute the remaining petrol content further a.s.a.p).

[1ozzy]

Yep, Buenchico, pointless draining fuel at this stage.
Used cooking oil has lubricating qualities so wouldn't cause damage. Petrol is sometimes used as a de-greaser so has a different effect.
Seals are made from different compounds depending on the job they are designed for.

As to any long term damage it would depend on the ratio of petrol to diesel fuel the car ran on and for how long.

Fingers crossed Chinoo1 will get away with it.

[TWR]

The engine will have burned it off, " No Problems"

[retrocop]

With that ratio 18/50 it shouldn't be a problem by now. Some years back London Transport used to put petrol in their diesel buses in Winter because the diesel did not contain the additives it does now. The derv used to "gel up" in the cold temperature so petrol changed the viscosity a bit.

[TWR]

Brings back memories that trick Retro, never no problems.

[RATTER15]

I put petrol in a Nissan Cabstar many moons ago, it did a lot of damage. If I remember correctly, the damage was to the valve sears and valves and the injectors from overheating. If your vehicle is running ok now then I imagine it wont do any harm now.

[1ozzy]

IF there is any long term damage done it will be before the combustion chamber, injectors, fuel pump etc. It wont be noticeable in the short term. Depends on the ratio of petrol/diesel and distance run.
Not sure where 18/50 came from unless your diesel fuel costs 1 quid per litre.
Not sure how much diesel would be in the car if it is "on reserve" when 18 litres were added.

Hopefully Chinoo has escaped major damage.

[retrocop]

ozzy
!8 litres (petrol) was put in when vehicle on reserve. 50 litres of derv put in soon after to counter act the juddering.

[retrocop]

sorry. I mis read the post. It was £50 worth of diesel which would certainly be less than 50 litres.!!

[Chinoo1]

Yeah I have topped the car up with high quality diesel again, it runs like as it used to, the twin turbo seems to be kicking in nicely (I did put my foot down a lot recently to examine and it still don't miss a beat) as i said it sometimes takes a second or two longer to turn over/start up and that's what worries me. Thank you all for your advice and I will write here as I do more miles.

[TWR]

Methyl, totally unnecessary, the petrol will have been burnt by now.

[Chinoo1]

Did over 150 miles now and just topped it up with premium diesel again. Still running smooth, apart from took a second longer to turn on again off the forecourt of the petrol station.

[ToraToraTora]

you're fine, the petrol would have been diluted into the diesel and it's effect will now be negligible. treat it to a bottle of this: http://www.ebay.co.uk/itm/New-Redex-Diesel-Fuel-System-Cleaner-500ml-/111691399536?hash=item1a01538170

[stocksman]

You've probably avoided the worst case scenario by filling up as soon as poss. with diesel. If you hadn't done that the petrol being ignited by 'compression ignition' as used in diesels would quite likely have been much hotter than the engine was designed for and would cause minute(or larger) cracks in the cylinder head but you've probably got away with it this time.
Retro, when I was in the Royal Engineers we used to add an amount of paraffin to the diesel tank, rather than petrol. Paraffin is much less likely to cause problems as it has some degree of lubrication properties, unlike petrol and so would have less effect on the system seals etc.