Petrol in a Diesel 90 Defender
Discussion
I've just cut and paste the following after putting it in the Landrover forum, not sure I'll get a reply there and needed to speak to him when he returned home, if he makes it
Just recieved a text from a mate who has done the above. Reckons 60/40 only 10 gallons of petroleek He said he didn't realise until the car started chugging (his words) after about 80 miles. He's now on his way again after putting in 4 gallons of premium performance diesel and said the car is now okayconfused his plan is to continue to stop every 50 miles and brim the tank, is this even possibleconfused
I've told him to pull over at the first service station and call out the AA, his reply " I've only got 95 miles left to get homeeek What's the likely scenario here, do you reckon he's shagged the fuel pump? By the way his car is quite new 13 plate so has the 2.2 engine.
Just recieved a text from a mate who has done the above. Reckons 60/40 only 10 gallons of petroleek He said he didn't realise until the car started chugging (his words) after about 80 miles. He's now on his way again after putting in 4 gallons of premium performance diesel and said the car is now okayconfused his plan is to continue to stop every 50 miles and brim the tank, is this even possibleconfused
I've told him to pull over at the first service station and call out the AA, his reply " I've only got 95 miles left to get homeeek What's the likely scenario here, do you reckon he's shagged the fuel pump? By the way his car is quite new 13 plate so has the 2.2 engine.
Ouch.
If I recall correctly JLR's request for a misfuel is to replace literally every single component in the fuel system regardless of amount or the warranty will become null and void, so that would give me some sort of idea how much tolerance they think the system has.
That being said, in for a penny, in for a pound. If any damage was to be done it is well and truly done now, I'd keep going and hope for the best.
If I recall correctly JLR's request for a misfuel is to replace literally every single component in the fuel system regardless of amount or the warranty will become null and void, so that would give me some sort of idea how much tolerance they think the system has.
That being said, in for a penny, in for a pound. If any damage was to be done it is well and truly done now, I'd keep going and hope for the best.
I'm expecting a call shortly as he said he would ring me at his next stop. 
I didn't think petrol in a diesel would mess up the engine as badly as diesel in a petrol.
My thinking is, diesel tends to be a bit harder to set light to, hence why diesel engines have a stronger block as they need higher pressures to heat the air so they can effectively burn the diesel, whereas petrols rely on a spark, not heat and pressure.
So therefore, petrol should still burn in a diesel engine. Sure, you'll get a rough running engine, but the pressure/heat should still ignite the petrol, as it's more volatile than diesel, and is easier to burn.
So, if you've completely filled up the tank, then don't drive it, but if you've put maybe a 1/3rd of a tank, then topped it up with diesel, then I'd be surprised if you manage to kill the car?
My thinking is, diesel tends to be a bit harder to set light to, hence why diesel engines have a stronger block as they need higher pressures to heat the air so they can effectively burn the diesel, whereas petrols rely on a spark, not heat and pressure.
So therefore, petrol should still burn in a diesel engine. Sure, you'll get a rough running engine, but the pressure/heat should still ignite the petrol, as it's more volatile than diesel, and is easier to burn.
So, if you've completely filled up the tank, then don't drive it, but if you've put maybe a 1/3rd of a tank, then topped it up with diesel, then I'd be surprised if you manage to kill the car?
TheInsanity1234 said:
I didn't think petrol in a diesel would mess up the engine as badly as diesel in a petrol.
My thinking is, diesel tends to be a bit harder to set light to, hence why diesel engines have a stronger block as they need higher pressures to heat the air so they can effectively burn the diesel, whereas petrols rely on a spark, not heat and pressure.
So therefore, petrol should still burn in a diesel engine. Sure, you'll get a rough running engine, but the pressure/heat should still ignite the petrol, as it's more volatile than diesel, and is easier to burn.
So, if you've completely filled up the tank, then don't drive it, but if you've put maybe a 1/3rd of a tank, then topped it up with diesel, then I'd be surprised if you manage to kill the car?
It's the fuel system that it upsets. Modern common rail fuel systems operate at circa 30,000 psi iirc and have aviation tolerances so need spotlessly clean fuel and filters. Petrol does not have enough lubricating properties and so shags the pump in short order. My thinking is, diesel tends to be a bit harder to set light to, hence why diesel engines have a stronger block as they need higher pressures to heat the air so they can effectively burn the diesel, whereas petrols rely on a spark, not heat and pressure.
So therefore, petrol should still burn in a diesel engine. Sure, you'll get a rough running engine, but the pressure/heat should still ignite the petrol, as it's more volatile than diesel, and is easier to burn.
So, if you've completely filled up the tank, then don't drive it, but if you've put maybe a 1/3rd of a tank, then topped it up with diesel, then I'd be surprised if you manage to kill the car?
TheInsanity1234 said:
I didn't think petrol in a diesel would mess up the engine as badly as diesel in a petrol.
My thinking is, diesel tends to be a bit harder to set light to, hence why diesel engines have a stronger block as they need higher pressures to heat the air so they can effectively burn the diesel, whereas petrols rely on a spark, not heat and pressure.
So therefore, petrol should still burn in a diesel engine. Sure, you'll get a rough running engine, but the pressure/heat should still ignite the petrol, as it's more volatile than diesel, and is easier to burn.
So, if you've completely filled up the tank, then don't drive it, but if you've put maybe a 1/3rd of a tank, then topped it up with diesel, then I'd be surprised if you manage to kill the car?
You can't get diesel in a petrol these days, the nozzle's too big.My thinking is, diesel tends to be a bit harder to set light to, hence why diesel engines have a stronger block as they need higher pressures to heat the air so they can effectively burn the diesel, whereas petrols rely on a spark, not heat and pressure.
So therefore, petrol should still burn in a diesel engine. Sure, you'll get a rough running engine, but the pressure/heat should still ignite the petrol, as it's more volatile than diesel, and is easier to burn.
So, if you've completely filled up the tank, then don't drive it, but if you've put maybe a 1/3rd of a tank, then topped it up with diesel, then I'd be surprised if you manage to kill the car?
The reason petrol can knacker diesels is that diesel is used as a lubricant for various bits of the fuel system, petrol doesn't have the same lubricating properties.
So him saying that the car now seems fine after adding more diesel would not make any sense? He should be home in about 20 min's so can find out a bit more then. By this time he will have driven it over 150 miles after adding 10 gallons of petrol 
and diluting it with a further 7/8 gallons of diesel.
and diluting it with a further 7/8 gallons of diesel.tony wright said:
So him saying that the car now seems fine after adding more diesel would not make any sense? He should be home in about 20 min's so can find out a bit more then. By this time he will have driven it over 150 miles after adding 10 gallons of petrol and diluting it with a further 7/8 gallons of diesel.
It will run better on the correct fuel.and diluting it with a further 7/8 gallons of diesel.The potential damage to the high pressure fuel system through lack of lubrication could cause issues.
Willy Nilly said:
It's the fuel system that it upsets. Modern common rail fuel systems operate at circa 30,000 psi iirc and have aviation tolerances so need spotlessly clean fuel and filters. Petrol does not have enough lubricating properties and so shags the pump in short order.
oilslick said:
You can't get diesel in a petrol these days, the nozzle's too big.
The reason petrol can knacker diesels is that diesel is used as a lubricant for various bits of the fuel system, petrol doesn't have the same lubricating properties.
Oh, ah.The reason petrol can knacker diesels is that diesel is used as a lubricant for various bits of the fuel system, petrol doesn't have the same lubricating properties.
So it's not actually the fact it stops the engine from igniting the fuel, but more a case of it causes the engine to seize up because of not enough lubrication?
That explains why my mum's friend managed to fill her tank up with petrol (diesel '06 Galaxy, and yes, she was a ditzy blonde woman, and her ex always filled it up for her) and drove it the short distance to our house (<0.25 miles) and ended up needing to have a very, very expensive engine rebuild.
And also explains why if you only put a bit of petrol in, then brimmed the tank with diesel, you'd just get rough running for a while as the petrol thins out the diesel.
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