Viewing: What happens if you put petrol in a Diesel engine?

***waynne*** · 22-04-2008, 09:29 AM

I know it will go bang and break but I was wondering if anyone knows the specifics of damage done. Has it happened to you? How much did it cost to put right.

**Izo Azlion** · 22-04-2008, 10:03 AM

As far as I know, Diesel engines are a much larger compression ratio than a petrol. So petrol, which is considerably more volatile, is going to go BANG and the engines going to completely crap itself and fall apart.

As for what exactly happens, I can only assume all the components cant take that sort of pressure and various bits will snap/bend/break.

Best thing to do if you put Diesel in is not turn the ignition, but call AA or something, and get them to drain the tank. It'll only cost upto a few hundred quid, rather than grands.

***HDi fun*** · 22-04-2008, 10:22 AM

Most IDI cars without turbos will stand up to 30% petrol mixed with diesel. Before the days of winter diesel it was common to add 5-10% to keep the diesel from turning to wax.

Modern diesels - DON'T DO THIS. You'll trash the high pressure pump because petrol is nowehere near as lubricating as diesel.

Definitely don't start it.

maddaveuk1 · 29-05-2008, 10:15 AM

suggestion about petrol in deisel engine, e-mail topgear to do a mad experiment and get the results for us drivers of dervs because anybody can make a mistake if they are colour blind and dislectic. the engine will probaly have nervous break down and fall to bits. ha ha

***waynne*** · 29-05-2008, 11:49 AM

It would be an interesting episode. I think Diesel in a Petrol engine would make for better viewing - it would be like a smoke machine :LOL:

**pgarner** · 29-05-2008, 02:55 PM

id forgotten about time thread

wifes mate put about 7 ltrs of petrol in her clio by accident, she had been driving her brothers car for the last couple of days, she necked it with diesel and ran without any issues that was last week.

***HDi fun*** · 29-05-2008, 06:46 PM

What engine was in the Clio?

***waynne*** · 30-05-2008, 07:16 AM

Would the petrol float in the tank over the diesel? Could be a whole lotta trouble brewing!

**Izo Azlion** · 30-05-2008, 08:57 AM

Quote:

Originally Posted by waynne

Would the petrol float in the tank over the diesel? Could be a whole lotta trouble brewing!

Thats a good guess. Would part of it maybe dilute every time you fill it? Cos, if so, you'd have to refill at say, half a tank, to keep the petrol from reaching.

**pgarner** · 30-05-2008, 10:58 AM

Quote:

Originally Posted by HDi fun

What engine was in the Clio?

the 1.5 dci that nice little cheap £35 a year tax one

never thought about the petrol being less dense in than the diesel.

might warn her about that

**Two Tone Tribe** · 30-05-2008, 11:28 AM

ooh, i would love to see a petrol engine go bang due to not putting in the right petrol. so long as its not my car.
would be quite cool seeing jeremy clarksons hate for diesel. he probably would love to do it.
Enjoi

**pgarner** · 30-05-2008, 12:31 PM

not seen a petrol go bang for putting diesel in it. gets very smoky thou

***HDi fun*** · 01-06-2008, 01:25 AM

Even Clarkson has changed his 'tune' a little. Diesels are no longer the repesentatives of the anti-christ even in his opinion.

**jarrus** · 01-06-2008, 08:59 AM

my mom fill our old land rover discovery TD5 full of petrol
whatever you've seen on the tele or heard on the radio is rubbish...
all that happens is that your engine cuts out because petrol doesn't burn as slow and diesel so won't work well...
all we did was drain the fuel tank (which means i had loads of mouthfuls of petrol YUK!) and drain as much as you can out the system
and fill with diesel and you just have to run the rest out it out....
There wil lots of coughs and spluttering and lots and lots and lots and lots and lots of blue/white smoke but eventually it goes and everything then is fine....

***HDi fun*** · 01-06-2008, 11:52 AM

High injection pressure diesels can be completely killed by petrol even at very small dilutions. Petrol strips all the lubricity of the diesel fuel from pumps and injectors which leads to their rapid demise.

I would suggest that you don't even try to start a modern diesel if there's ANY petrol in the tank at all.

**jarrus** · 01-06-2008, 05:36 PM

She got about 5 miles before it cut out but we jsut did all that as described before adn it's worked fine (we've got the new discovery 3 now though with the TDV6 hasvn't done it in that one)

and I've just thought then if petrol in a diesel in engine is worse than putting diesel in a petrol engine why is it that a diesel filler pump nozzole won't fit in a petrol car and a petrol one can fit in a diesels? Surely that has something to do it
(this applies to UK petrol stations not sure on the rest of the world)

**steve09** · 20-06-2008, 06:52 PM

Quote:

Originally Posted by jarrus464

and I've just thought then if petrol in a diesel in engine is worse than putting diesel in a petrol engine why is it that a diesel filler pump nozzole won't fit in a petrol car and a petrol one can fit in a diesels? Surely that has something to do it
(this applies to UK petrol stations not sure on the rest of the world)

umm.... it does.. someone i know put in 10 litres of diesel into his 106 then to water it down he put another 10 of petrol in it. it ran.. but chucked out LOADS of smoke an had a lot of power down

**jarrus** · 20-06-2008, 08:02 PM

Quote:

Originally Posted by steve09

umm.... it does.. someone i know put in 10 litres of diesel into his 106 then to water it down he put another 10 of petrol in it. it ran.. but chucked out LOADS of smoke an had a lot of power down

don't know which petrol station he went to then....lol

**steve09** · 23-06-2008, 07:27 PM

in kent there all the same... dont really look at diesel pumps much part from to fill up my mates car for him a couple of times but ive never noticed any difference in shape to petrol.

**claymore** · 23-06-2008, 08:06 PM

put £20 of petrol in my citroen zxtd a couple of weeks ago topped it up with £40 of diesel and apart from being a bit down on power it drove fine, didn't like to start when warm though, since then it's had another £30 worth of diesel and its back to normal, starts first time

**KJD** · 26-08-2008, 11:31 PM

I put 14 pence of diesel in My mothers passat which is the 2006 tdi 170, realised just as i was putting it in. put about 20 quid of diesel in straight after and it ran fine to this day, although that was only 14 pence lol.

**billyo** · 27-08-2008, 09:05 AM

14 p (of petrol I presume) would be about a gnats crotchet at todays prices. I bet you were cursing yourself. Did you have to pay in 2 batches 14p and then £638 for the Diesel?

**KJD** · 27-08-2008, 03:10 PM

Quote:

Originally Posted by billyo

14 p (of petrol I presume) would be about a gnats crotchet at todays prices. I bet you were cursing yourself. Did you have to pay in 2 batches 14p and then £638 for the Diesel?

lol. yeah i did i looked like a complete loser. went in and payed for 14p in exact change then put diesel in.

***waynne*** · 27-08-2008, 03:21 PM

Thats funny!

**prevtec** · 27-08-2008, 06:01 PM

i dont know exactly what happenes,as i never had a diesel motor but i put diesel in my type r civic before,when i realized i had put 15 euros of it in,bollo;s,so i put another 15 petrol in and drove so slow i was almost stopped never did any damage.a fella told me if anything it would clean my engeine,or was i lucky??