Petrol into diesel

[cheddar]

I scrapped my little 2005 250k mile Citroën C2 1.4 diesel today after catastrophic gearbox failure.
As I had just filled it to the brim with diesel moments before it’s demise, I used an electric pump to drain the tank, and couldn’t resist adding some weight to the car as it was going on the weighbridge. Amongst all the scrap metal that I dragged out of the garage and thrown on the back seats I also decided to add some ballast to the now empty fuel tank.
This consisted of 25 litres of used engine oil, 5 litres of dirty cooking oil out of an old (now on in the boot) fryer, 4 litres of 2yr old manky petrol, and finally a couple of litres of sludgy brown diesel out of an old space heater.
I primed the fuel system and after a few turns it started. It ran absolutely fine. I let it warm up, still no smoke, no engine light on, turned it off, restarted it.
Eventually after approx 20 mins (I was doing other things too), it sounded a bit “knocky“. It would still Rev cleanly with no smoke though.
This would’ve done pretty bad things to the entire fuel system, mainly the high-pressure fuel pump and common-rail injectors, but it just goes to show how much the management system can adapt, to mask the effects of bad fuel.
It was still running ok after being yanked a few miles by the merc to the scrapyard where it was revved till it took its last breath and choked us all.
Small amount of petrol? May be ok but if you can drain it for reasonable cost, it’s not worth the risk is it?

 

[Martygt550]

I would have gone to any motor factor and bought a pressure/vac oil/fuel extraction pump(sealy do a good one) they cost a fraction of the price quoted and taken it out on the forecourt,it's a great tool to have around the garage anyway!

 

[DITTRICH]

My elder son filled the E300 diesel estate with petrol by mistake and drove it until it cut out and wouldn't start. I told him the cost of a new engine and he started to get nervous. It was trailered to an independent who drained the fuel system and refilled it with diesel. It started first time. This was 50,000 miles and several years ago at least. The car still works. Then my wife also did the same a year later. The car still works. It may only do 45mpg on the motorway at 50 mph, but I dodged the bullet twice. There is something to be said for old cars.

 

[David404]

I'm risk adverse but I'd probably have had the tank drained and refilled. BUT what's done is done...

Given where you are keeping the tank topped off to dilute the petrol is probably wise. At some point I'd let the tank go down to low fuel light on 2 or 3 times in a row to be 100% all the petrol is out of the tank.

As somebody else said don't say a word about this to a MB dealer...

 

[Jonc220amg]

Update......

Cars still running no real issues but..... Cannot for love nor money get over 45mpg now and I took on a long stretch up the m11 (4 hour round trip) pre-petrol was reaching 60mpg on a long trip.

I wonder how long that will be for or possibility long term.

 

[DSM10000]

Update......

Cars still running no real issues but..... Cannot for love nor money get over 45mpg now and I took on a long stretch up the m11 (4 hour round trip) pre-petrol was reaching 60mpg on a long trip.

I wonder how long that will be for or possibility long term.

Are you comparing exact conditions, traffic density and, more importantly with a diesel, outside temperature?

 

[GeeJayW]

It may be that the ECU made a fuel trim adjustment after your incident, but I would not expect that to be permanent.

For what it's worth, we only get about 47mpg from ours. Maybe over 50 on a steady run, but that's being very gentle on the pedals.

 

[Mob17]

I always triple check at the pump as this is my worst fear