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What happens if you put petrol in a Diesel engine?

Discussion in 'Diesel Chat' started by obi_waynne, 22 April 2008.

  1. obi_waynne

    obi_waynne Administrator Staff Member Moderator

    Media:
    2,214
    Albums:
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    Location:
    Deal, Kent UK
    Car:
    A3 2.0 TDI
    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.
     
  2. Izo Azlion

    Izo Azlion Road burner

    Location:
    Manchester
    Car:
    Golf GT TDI Sport
    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.
     
    obi_waynne likes this.
  3. HDi fun

    HDi fun TC Professional

    Media:
    13
    Albums:
    1
    Location:
    Buckinghamshire UK
    Car:
    Passat 2.0 TDi 170
    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.
     
  4. maddaveuk1

    maddaveuk1 Grease Monkey

    Location:
    third planet
    Car:
    astra 1.7 tdi sport
    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
     
  5. obi_waynne

    obi_waynne Administrator Staff Member Moderator

    Media:
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    Albums:
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    Location:
    Deal, Kent UK
    Car:
    A3 2.0 TDI
    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:
     
  6. pgarner

    pgarner TC Founder Moderator

    Media:
    45
    Albums:
    2
    Location:
    Lockerbie, SW Scotland
    Car:
    Octy smoke machine
    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.
     
  7. HDi fun

    HDi fun TC Professional

    Media:
    13
    Albums:
    1
    Location:
    Buckinghamshire UK
    Car:
    Passat 2.0 TDi 170
    What engine was in the Clio?
     
  8. obi_waynne

    obi_waynne Administrator Staff Member Moderator

    Media:
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    Location:
    Deal, Kent UK
    Car:
    A3 2.0 TDI
    Would the petrol float in the tank over the diesel? Could be a whole lotta trouble brewing!
     
  9. Izo Azlion

    Izo Azlion Road burner

    Location:
    Manchester
    Car:
    Golf GT TDI Sport

    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.
     
  10. pgarner

    pgarner TC Founder Moderator

    Media:
    45
    Albums:
    2
    Location:
    Lockerbie, SW Scotland
    Car:
    Octy smoke machine

    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
     
  11. Two Tone Tribe

    Two Tone Tribe Wrench Pro

    Location:
    Glasgow
    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
     
  12. pgarner

    pgarner TC Founder Moderator

    Media:
    45
    Albums:
    2
    Location:
    Lockerbie, SW Scotland
    Car:
    Octy smoke machine
    not seen a petrol go bang for putting diesel in it. gets very smoky thou
     
  13. HDi fun

    HDi fun TC Professional

    Media:
    13
    Albums:
    1
    Location:
    Buckinghamshire UK
    Car:
    Passat 2.0 TDi 170
    Even Clarkson has changed his 'tune' a little. Diesels are no longer the repesentatives of the anti-christ even in his opinion.
     
  14. jarrus

    jarrus Torque Junkie

    Location:
    Cannock, SouthStaffs, UK
    Car:
    205 1.8 TD
    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....
     
  15. HDi fun

    HDi fun TC Professional

    Media:
    13
    Albums:
    1
    Location:
    Buckinghamshire UK
    Car:
    Passat 2.0 TDi 170
    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.
     
  16. jarrus

    jarrus Torque Junkie

    Location:
    Cannock, SouthStaffs, UK
    Car:
    205 1.8 TD
    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)
     
  17. steve09

    steve09 Senior member<br />Oct Nurburgring Champ

    Media:
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    Albums:
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    Car:
    Honda NSR 125R
    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
     
  18. jarrus

    jarrus Torque Junkie

    Location:
    Cannock, SouthStaffs, UK
    Car:
    205 1.8 TD
    don't know which petrol station he went to then....:lol:
     
  19. steve09

    steve09 Senior member<br />Oct Nurburgring Champ

    Media:
    18
    Albums:
    2
    Car:
    Honda NSR 125R
    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.
     
  20. claymore

    claymore The Torque Meister

    Media:
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    Albums:
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    Location:
    Shrewsbury
    Car:
    T-5k,
    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
     
  21. KJD

    KJD Wrench Kid

    Location:
    Sheffield
    Car:
    2002 Civic coupe
    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: .
     
  22. billyo

    billyo Track Warrior

    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?
     
  23. KJD

    KJD Wrench Kid

    Location:
    Sheffield
    Car:
    2002 Civic coupe
    :lol: . yeah i did i looked like a complete loser. went in and payed for 14p in exact change then put diesel in. :embarrest::embarrest:
     
  24. obi_waynne

    obi_waynne Administrator Staff Member Moderator

    Media:
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    Location:
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    Car:
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    :lol: Thats funny!
     
  25. prevtec

    prevtec Torque Junkie

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    Location:
    ireland
    Car:
    prelude 2.2vtec jap
    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??
     
  26. HDi fun

    HDi fun TC Professional

    Media:
    13
    Albums:
    1
    Location:
    Buckinghamshire UK
    Car:
    Passat 2.0 TDi 170
    Small dilutions of diesel won't hurt a petrol engine. It certainly won't clean anything though, and might harm the cat and lambda sensor(s)
     
  27. muzzer

    muzzer Grease Monkey

    Location:
    cheshire
    Car:
    astra cdti150 sri
    i did it last yr. filled to brim with petrol on xmas eve drove home from local petrol station approx 800 metres car started misfiring as i got it on drive when i tried to start it wouldnt start realised wot i had done cost me £80 to have petrol drained and the cost of the petrol did i feel stupid
     
  28. muzzer

    muzzer Grease Monkey

    Location:
    cheshire
    Car:
    astra cdti150 sri
    i did it last yr. filled to brim with petrol on xmas eve drove home from local petrol station approx 800 metres car started misfiring as i got it on drive when i tried to start it wouldnt start realised wot i had done cost me £80 to have petrol drained and the cost of the petrol did i feel stupid didnt do my engine any harm
     
  29. billyo

    billyo Track Warrior

    That cant have helped your MPG at the time it sounds like you were lucky though for it not to do any harm. Was this in the Astra?
     
  30. Loz

    Loz Torque King

    Media:
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    Location:
    Wolverhampton, U.K.
    Car:
    MX-5
    Am I right in thinking that an old bodge to get your old smokey derv through it's Mot was to mix some petrol in, to reduce the emmisions?
    Would't suggest it with modern engines though :shock:
     

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