Unleaded into an A3 Tdi?

[wanta996]

I mistakenly put Unleaded into my wifes A3 Tdi, i noticed after 5 litres and made sure to put another 25litres od Diseal to try to neutralise it?? - Anyone got any views an ideas as it has failed to start initailly but then it eventually starts up? Am i doing any damage? Any views would be welcome.

[JRP]

it will run, but iam led to belive after doing it to my van, that it will fail on emisions or somthing alike.. how true this is iam unsure, but i put about 10 quids worth into my van and its still ok

[00161wj]

Best to drain it and stick a fuel filter on as either the diesel or the petrol floats on top of the other.

[catso]

My Father in law put unleaded in his Merc, realised what he'd done and so topped up with Diesel then drove it 'till it died. Cost him a lot of money (he didn't want to say how much but at least a couple of grand) - I'd drain it all out then flush through if I were you.

[AndyAudi]

catso said:

My Father in law put unleaded in his Merc, realised what he'd done and so topped up with Diesel then drove it 'till it died. Cost him a lot of money (he didn't want to say how much but at least a couple of grand) - I'd drain it all out then flush through if I were you.

When my old man picked up his new ML he was told not to put petrol in it as it would cost in excess of £5k

[I Cooke]

It's an expensive risk to take, I'd flush the system. Petrol in a diesel is much worse than putting diesel in a petrol engine.

[Brink]

I Cooke said:

It's an expensive risk to take, I'd flush the system. Petrol in a diesel is much worse than putting diesel in a petrol engine.

Why?

[I Cooke]

Because the diesel fuel pump relies on the diesel itself for lubrication. Petrol doesn't have the same lubricity so your pump will wear out very quickly. As you can imagine parts like an Audi common rail pump aren't cheap.

On the other hand your petrol pump won't suffer from pumping diesel.

Edited by I Cooke on Monday 19th March 12:45

[Brink]

I Cooke said:

Because the diesel fuel pump relies on the diesel itself for lubrication. Petrol doesn't have the same lubricity so your pump will wear out very quickly. As you can imagine parts like an Audi common rail pump aren't cheap.

On the other hand your petrol pump won't suffer from pumping diesel.

Edited by I Cooke on Monday 19th March 12:45

A small amount of p in d won't do any harm.

A small amount d in p will bugger the lamda.

[I Cooke]

5 litres out of 30 is more than a little in my opinion. I personally wouldn't run with anything more than 10% petrol in diesel and I'm sure any mechanic will tell you the same.

Lambda sensor ~£60
Diesel pump repairs can run into £1000's

[Brink]

Fair enough...

[catso]

Brink said:

I Cooke said:

It's an expensive risk to take, I'd flush the system. Petrol in a diesel is much worse than putting diesel in a petrol engine.

Why?

My Sister filled her Petrol car with Diesel, drove a couple of miles 'til the diesel got through to the engine and it stopped.

Had it cleaned out, no damage at all.

I don't think Diesels which have ultra-high Compression ratios (by petrol engine standards) can cope with Petrol whereas Diesel just doesn't burn in a petrol.

[wanta996]

Just an update guys, first day it was a bit of a nightmare as the car kept cutting out when i slowed down at roundabouts or junctions etc, it also wouldnt start first time i turned the ignition on BUT since i have re-filled the car with diesel after running it dry - the car has been running perfect - fingers crossed - i will keep you guys updated just incase you or anyone you know foolishly does the same thing i did.

[theaxe]

Isn't the best thing to do to use up a gallon, refill with diesel, use up another gallon and so on rather than running it dry and refilling?