Diesel car running rough after putting Petrol in

Need_More_Money_2

x_raphael_xx wrote: »

Petrol into a diesel car you can usually get away with. Diesel in a petrol car is a no-no.

My understanding was that it was the other way around, especially with modern cars. The advice is usually not to even unlock the doors on a modern diesel car if you put in any petrol.

Conor_3

You've got it the wrong way round. Diesel in a petrol car kills the catalytic converter.

And I guess the advice about not unlocking the doors is aimed at the terminally stupid.

david29dpo

Conor wrote: »

When it's very cold, sometimes petrol is mixed with diesel to stop it freezing...

NEVER do this, paraffin is used.

oldagetraveller

david29dpo wrote: »

NEVER do this, paraffin is used.

No, Conor's right. It always was a recommendation to add a VERY small amount of petrol in winter. This was of course before the advent of "winter" Diesel fuel.
Parrafin is/was NOT allowed because it is duty free, same as "pink" Diesel, and technically an offence was being commited if added to tank for road use.

Conor_3

Exactly. That's the main reason why those paraffin dispensers you used to see at petrol stations ages ago disappeared.

bunking_off

Conor wrote: »

And I guess the advice about not unlocking the doors is aimed at the terminally stupid.

Nope. On some modern diesels the action of unlocking the car causes the fuel pump to be primed/glowplugs activated, in order that the car can be started immediately the key is put in the ignition.

See this.

As an aside, unrelated to the diesel issue but on my petrol Jag unlocking the car certainly causes something to be armed (I've always assumed the fuel pump) because you can hear the electrical buzz.

Neither petrol in diesel nor diesel in petrol engines are good. I gather the latter is pretty rare nowadays due to the nozzle shapes. However, from what I've read petrol into diesel can be worse, because you can need half a new engine (versus a new cat-converter for the other way around).

Conor_3

bunking_off wrote: »

Nope. On some modern diesels the action of unlocking the car causes the fuel pump to be primed/glowplugs activated, in order that the car can be started immediately the key is put in the ignition.

Never knew that. THanks.

It's getting ridiculous now isn't it? Something else to go wrong.

bunking_off

Thinking about it, on my car the fuel pump is primed when the key goes in the ignition (just key in ignition, not turned) rather than when it's unlocked. Does seem a bit OTT to do it off the central locking.

You can imagine the irony, though, can't you. Fill your diesel car with petrol. Realise your mistake before you set off, and call the AA. At this stage it's just a "drain the tank" scenario. While waiting put the key in the dash to listen to the radio to pass the time....and do a few hundred quid's more damage...

In fact, makes me wonder on the diesel versions of Jags...I assume they have the same electric parking brake which clearly can only be released with keys in ignition. Catch 22...can't move car to drain tank without releasing parking brake, can't release parking brake without keys in ignition, can't put key in ignition without causing further damage. I'm sure someone's thought of a way around that...

Need_More_Money_2

Conor wrote: »

You've got it the wrong way round. Diesel in a petrol car kills the catalytic converter.

But on the high pressue common rail time diesels I think petrol in disesel engine can do much more damage that that.

Conor wrote: »

And I guess the advice about not unlocking the doors is aimed at the terminally stupid.

Someone else has already mentioned it, but it was also my understanding that opening the door starts the priming of pumps and glowplugs which is why it appears there is less of a delay in starting a diesel car than there used to be.

Chall

how on earth can you forget whether you take petrol or diesel?!