General Multipla mistake: I put unleaded in my diesel

[MarkX]

Hello Folks,

I absentmindedly put 1 gallon (4.5L) of unleaded in my '01 Multipla 1.9 JTD this evening instead of diesel. Spotted the mistake and put in a gallon of diesel as well. Drove home about 6 miles with no problems. Tank was just under 1/4 full before fill-up.

Should I be worried, should I take any corrective action?

Mark

 

[Mad one]

If I was you I would fill the rest of the tank ( with diesel of course ) this will them really dilute down the mixture, at one time in the frozen parts of this world, petrol was used to stop the diesel waxing and clogging up the filter.

HOWEVER all this is at your risk of course, as you have already drove with a strong petrol / diesel mix, there is a chance you may have started to damage the seals and running parts of the pump.

The only other alternative now, would be to have the tank drained and flushed and the refilled with diesel.

The choice is yours, luckily the multipa has a relatively old type of engine and it is more likely to survive.......

Best of luck!

 

[portland_bill]

As Mad one says, you need to dilute it more. Fill up with diesel as soon as possible. Then drive gently until tank is no less than half empty and fill again.

If you can safely leave it overnight with the fuel cap off, do so. It will allow a lot of the petrol to evaporate off. Your own driveway, not on the road. Not where anyone smoking passes nearby.

 

[MarkX]

Thanks both of you.

M.

 

[widemouthfrog]

As above, fill it with diesel. You could also add a slug of 2 stroke oil as this will readily mix with the petrol and diesel and lubricate the pump. Aside from the compression/ignition problems of petrol in a diesel engine, the main 'mechanical' issue is with the diesel pump, which relies on the lubricating properties of diesel.

I've seen quite a few threads on other fora where folk recommend adding 2 stroke oil to diesel as standard practice, especially now that biodiesel makes up a significant percentage of the regular diesel sold by most garages.

 

[Oletimer]

With the amount of diesel already in the tank I don't think you need fret too much. During winter I always add a gallon of petrol and 1/2 pint engine oil to my Ugly bugs tank before topping it up with diesel - I have also taken to using Shells 'V' diesel, my ugly loves it and returns significantly better mpg too. I have never had a problem, it starts first time in any weather and runs beautifully.
This something that has been done in my family for years - my father did it since the 1950's without any problems and those engines were animals to fire up when the weather got down to freezing.
George

 

[MarkX]

Add some clean engine oil... OK will do. How about 1/4 pint oil mixed with a gallon of diesel?

I can't afford to fill the tank full, so I put in another 5 gallons of diesel Today. The tank's over half full, with I reckon about 8 gallons of diesel to 1 of unleaded. Been out for a run this afternoon, about 20 miles, and touch wood the car's running fine.

About the fuel pump... Expensive? Easy to replace? Where is it exactly? Just curious...

Mark

 

[MarkX]

About the fuel pump... Expensive? Easy to replace? Where is it exactly? Just curious...

Expensive: Ebay: £39-95. Seems reasonable.

Easy to replace? Doesn't look too bad a job, but need a special tool to undo the lock collar?:

https://docs.google.com/viewer?a=v&...nxmaWF0bXVsdGlwbGF8Z3g6NTM3MjNmZmE1YWRiZThmYg

Where is it? In the fuel tank.

Anyone want to add anything?

M.

 

[GrandeGuy]

I put £50 of petrol I'm my 09 transit connect, started amazing cold but would hardly start hot, I just kept adding diesel every time it dropped to a quarter, I had it for 30'000 miles after that and it never missed a beat, but just syphoning the tank changing the filter and refilling with diesel is my best opinion.

 

[widemouthfrog]

Expensive: Ebay: £39-95. Seems reasonable.

Easy to replace? Doesn't look too bad a job, but need a special tool to undo the lock collar?:

https://docs.google.com/viewer?a=v&...nxmaWF0bXVsdGlwbGF8Z3g6NTM3MjNmZmE1YWRiZThmYg

Where is it? In the fuel tank.

Anyone want to add anything?

M.

It's not the fuel tank pump that'll have the problems - it's the injector pump in the engine bay. But don't worry about it for now - wait a while and see how it runs. Changing the injector pump can be complex.

 

[MarkX]

OK thanks.

 

[mrcinquecento]

It'll be fine, think i'd be tempted to top it up to the brim with diesel though (if possible, if not just keep topping up before it's really needed), run it a bit (down to half a tank) then top it up again long before it's really needed, just to dilute it further and quickest, by the time it's been through that and topped back up again, it will be gone to within a trace.

Wouldn't worry tbh

 

[MarkX]

Hey, Guess what? I did it again, only worse this time - I gormlessly put 15 quid (3 gallons) of unleaded in my Multipla tank! and :bang:

Realised right away, so filled the tank with diesel. I was just into the reserve when I pulled into the gas station, the manual says the reserve is 7L, and the whole tank is 65L. So once completely filled I reckon I had a tank of 13.5L of unleaded to 52.5L of diesel, so almost exactly 1:4 unleaded to diesel.

I know what you're going to say now... too late... don't switch the engine on... and call the fuel drain guys.

Well the car started OK and ran OK, maybe below par, or is that my imagination?

Drove home, and then read all the horror stories about contaminating diesel with unleaded, the main horror being that diesel, being oily, lubricates the fuel pump and components, and unleaded acts as a solvent, potentially causing the pump to blow up, then swarf finding it's way into the engine and knackering that as well.

Too embarassed to have my neighbours' see the "This W**ker's Put The Wrong Fuel In His Car (Again)" fuel drain vehicle show up outside my house, I have thrown 400ml of clean engine oil mixed with some diesel into the fuel tank. And today I've thrown in a litre of (clean) vege oil mixed with a gallon of diesel to provide some lubrication - or to give it the correct name I learned Today - "Lubricity".

Drove around for about 20 miles Today, still starting OK and running. Don't know if this will last.

Found a diesel fuel additive which is designed to provide lubricity so might get some, till I'm back to 100% diesel, or the fuel pump and then engine go bang. Also found something in Halfords which reconditions the fuel system after a misfuel (presumably to use after you've cleaned the fuel system).

If the witches brew that now resides in my fuel tank - unleaded, diesel, engine oil and rapeseed oil - works, I might try drinking some to see if it adds some years to my life!

Feel free to add humorous or other comments.

I'm crossing my fingers and avoiding black cats.

 

[portland_bill]

As I said before, if possible, leave the fuel cap off to allow the more volatile elements of the petrol to evaporate. This will do more good than any of the additives you've used.
Top up with diesel when you get to 3/4. Keep doing this for several top-ups.
And drive it gently.

I'd expect the petrol to rise to the top of the tank, so the engine is sucking mostly diesel. So leaving cap off is best, as long as it is in a safe place, away from fire.

 

[MarkX]

Thanks. That is reassuring. I am parked on a public street, but I'll leave the filler cap off when I'm in safe places over the weekend. Good to know the advice is coming from someone experienced.

 

[widemouthfrog]

Oh dear. Let's hope no damage is done.

You could also try adding a good slug of 2 stroke oil. It's soluble in petrol so will help to provide lubrication for the high pressure pump, which is the main bit of kit that won't like the petrol. Some folks recommend adding 2 stroke oil to diesel anyway, to help lube the HP pump, so it certainly won't do the system any harm. It's made to burn with a low ash, so shouldn't create too much carbon build up.

 

[g8rpi]

Thanks. That is reassuring. I am parked on a public street, but I'll leave the filler cap off when I'm in safe places over the weekend. Good to know the advice is coming from someone experienced.

Hi,
Don't worry too much about this. Keep topping up, preferably with premium diesel, when tank is 3/4 full. The diesel and petrol will be fully mixed in the tank, even left standing they won't separate. The main issue with petrol contamination is poor lubricity that can cause wear or seizure of pumps and injectors on modern direct injection (high pressure) diesel. Despite the lubrication issue don't add engine oil to the fuel with modern diesels, it is of little benefit and can leave deposits. The lubrication comes from surface modifying chemicals (sulphur and phosphorus were important but catalysts and emissions controls have virtually eliminated them) added to the fuel. Premium fuels tend to have better additive "packages". Use of a good diesel additive such as millers diesel power ecomax is also a good idea. The millers specifically says it has lubricity improvement, many, including Redex, are mainly cleaners and don't.
I know about this because I've done work on running gas turbine (jet) engines on alternative fuels and last year I put petrol in my 1.9 16V mJTD Croma. No excuse but it was foul weather, away from home, different brand (black pump handle), and the wife went in and paid so I missed that last chance to catch it and get it drained. It turned out to be a near perfect 50/50 mix, I didn't notice and drove over 200 fairly hard miles without stopping. Only thing was a slightly "lumpy" engine on over-run and slow re-start after a food stop (parked on steep hill) did another 100 miles on motorway pulled into services and checked last receipt

.
Brimmed it with quality diesel and drove (more gently) the remaining 100 miles home. Brimmed and added Millers for the next 3 3/4 levels in tank. then ran down to less than a 1/4 and brimmed for a final dilution. I've had no adverse affects. I also changed the fuel filter just in case it had been affected.
The de-fuel specialists and recovery companies will now tell you that just turning the ignition on will damage the pump (AA seemed to change their advice a couple of years ago and now offer a drain and flush service at extra cost). but clearly this is not the case for the mJTD (or JTD). I'd say up to 25% petrol in an older car, just brim it with diesel and don't flog it for a tank or two.


Robert G8RPI.

 

[MarkX]

Thanks g8rpi. Sounds like a plan. Will check out the Millers.

Shame about the misfuel. Engine had been running sweet as a nut recently, getting 45 MPG.

 

[g8rpi]

Thanks g8rpi. Sounds like a plan. Will check out the Millers.

Shame about the misfuel. Engine had been running sweet as a nut recently, getting 45 MPG.

Mine actually ran better with good MPG after the misfuel. Probably had a cleaning effect. I don't recommend it though. Things can be different with different engines.
The US military have done work on a single fuel for the battlefield and the choice was jet fuel, JP-8 (similar to civil Jet A1, kerosene / paraffin based) for aircfarft and land vehicles. They had issues with the fuel pumps in some Humvees and it was down to detail differences in manufacture. The pumps were interchangeable and all ran fine on diesel but some wore out when used with jet fuel. Answer is tighter specifications on the pumps or /and fuel additives.


Robert G8RPI

 

[glowplug]

Diesel is an oil, petrol is an alcohol/solvent. A diesel pump relies on the oil based nature of diesel to lubricate the working parts. Petrol cleans away the oil from the moving parts making them run metal to metal and the net result is failure. In actual fact oil does not lubricate it separates. As it resists compression two surfaces with oil in between experience an hydraulic effect called the hydraulic wedge. If it weren't for the reliance on this lubrication diesel engines would run on petrol (albeit not great) so I am sorry but the comments about seals failing are inaccurate. Maybe if immersed for a long time in petrol the rubber seals might start to degrade but it would not happen in the period of a misfuel. As other have correctly stated topping up with diesel is the best approach and 2 stroke can't hurt either. Even a small amount of 5w-30 will help if need be.

Diesel engines run VERY happily on engine oil as has been experienced by anyone who has suffered runaway due to a blown turbo seal or because of failed DPF regens causing an overflow of the sump.