I put a small amount of diesel in my '06 Prius and now it won't start

[kissinger]

So yesterday when I was filling up I foolishly put a small amount of diesel in my '06 Prius (the meter got to around £2.50 before I realised). I thought I would be okay if I just filled up the rest of the tank with petrol (which is what I did), but I've just went to start it and it's dead. 

It did start at first just now, but I think it was running on the residual Battery charge because the engine didn't kick in and the fuel gauge showed empty. I drove it around 10 miles home from where I filled up and then used it again later that evening. 

What should my next moves be? Is draining the tank and refilling likely to work or will it have caused more severe damage? I did read somewhere online that diesel in the tank can cause the gauges to go haywire so maybe if I can get it running and top up with a bit more petrol it will eventually 'flush' out the diesel?

[kithmo]

Weird that your fuel gauge is showing empty, but half a gallon of diesel in a ten gallon petrol tank shouldn't have any detrimental effect.

That's only about 5% diesel, no worse than running on 5% Ethanol Biofuel and the Prius can run on 10% Ethanol biofuel. 

It might be worth cleaning or changing the plugs if you're having difficulty starting it.

[kissinger]

1 minute ago, kithmo said:

Weird that your fuel gauge is showing empty, but half a gallon of diesel in a ten gallon petrol tank shouldn't have any detrimental effect.

That's only about 5% diesel, no worse than running on 5% Ethanol Biofuel and the Prius can run on 10% Ethanol biofuel. 

That's what I was hoping. I put £25 petrol in after the £2.50 of diesel, and the tank was already 10% full with petrol to begin with!

[Cyker]

I'd get it drained and the injectors flushed if I was you; Diesel owners can get away with a bit of petrol in the tank but the reverse isn't true as petrol engines physically can't burn diesel as they don't run anywhere near hot enough or have high enough injection pressure.

Diesel is much thicker than petrol and the fuel pump in a petrol engine will strain to pump it, and will have trouble forcing it out of the injector nozzles.

You can get away with IIRC 2% if it is mixed thoroughly, but if it's all settled at the bottom or 5%+ then you can get some major problems...

 

[AEB-UK]

Taken from the AA website:

"Petrol in diesel car

This is the more common call out we get as petrol nozzles fit easily into most modern diesel filter necks. It’s also the more serious of the two mistakes.

Diesel acts as a lubricant, helping the fuel pump to do its job. If petrol’s mixed with diesel it has the opposite effect, acting like a solvent. The more it’s pumped through your fuel system, the more damage it will do. It can even result in you needing a new engine.

Common rail (or HDi) diesel engines are particularly susceptible to damage from misfuelling. You could be looking at new fuel pumps, injectors, pipes, filters and fuel tank.

Diesel in petrol car

This is far less common as the diesel nozzle is physically larger than the petrol filler neck on most cars.

Around a third of the calls to AA Fuel Assist are for diesel in petrol, which can cause serious damage – particularly to direct injection (GDI) petrol engines."

 

However, given that the cost of engine repair, or at worse replacement, could run into thousands, and the cost of a drain and refill is considerably less, I would err on the safe side and call your roadside emergency service to sort it.

[rhory]

3 hours ago, kissinger said:

So yesterday when I was filling up I foolishly put a small amount of diesel in my '06 Prius (the meter got to around £2.50 before I realised). I thought I would be okay if I just filled up the rest of the tank with petrol (which is what I did), but I've just went to start it and it's dead. 

It did start at first just now, but I think it was running on the residual battery charge because the engine didn't kick in and the fuel gauge showed empty. I drove it around 10 miles home from where I filled up and then used it again later that evening. 

What should my next moves be? Is draining the tank and refilling likely to work or will it have caused more severe damage? I did read somewhere online that diesel in the tank can cause the gauges to go haywire so maybe if I can get it running and top up with a bit more petrol it will eventually 'flush' out the diesel?

2litres of diesel in a 45 litre tank of petrol  will dilute and burn off with no damage to anything, despite what the stealers tell you, I add 10% petrol to my diesels in the winter with no problems whatsoever makes for cleaner burning and easier starting.

[kithmo]

23 hours ago, Cyker said:

I'd get it drained and the injectors flushed if I was you; Diesel owners can get away with a bit of petrol in the tank but the reverse isn't true as petrol engines physically can't burn diesel as they don't run anywhere near hot enough or have high enough injection pressure.

Diesel is much thicker than petrol and the fuel pump in a petrol engine will strain to pump it, and will have trouble forcing it out of the injector nozzles.

You can get away with IIRC 2% if it is mixed thoroughly, but if it's all settled at the bottom or 5%+ then you can get some major problems...

 

Wrong way round Cyker, petrol in a modern diesel can ruin the injection pump by dissolving the seals, diesel in petrol lubricates the pump.

[Anthony Poli]

Is it more of a problem on a hybrid, because the engine isn't being run continuously ?

Does the fuel stay mixed, or will they separate again when stood for long enough?

 

[Cyker]

Only in the sense that the engine won't get as hot as a continuously run engine so the diesel will have more difficulty getting burnt.

They will separate over time if the tank is completely stationary but if you're driving around, going round corners etc. the movement should be enough to stop that happening I'd imagine.
 

[Anthony Poli]

On 01/06/2016 at 2:23 PM, kissinger said:

So yesterday when I was filling up I foolishly put a small amount of diesel in my '06 Prius (the meter got to around £2.50 before I realised). I thought I would be okay if I just filled up the rest of the tank with petrol (which is what I did), but I've just went to start it and it's dead. 

It did start at first just now, but I think it was running on the residual battery charge because the engine didn't kick in and the fuel gauge showed empty. I drove it around 10 miles home from where I filled up and then used it again later that evening. 

What should my next moves be? Is draining the tank and refilling likely to work or will it have caused more severe damage? I did read somewhere online that diesel in the tank can cause the gauges to go haywire so maybe if I can get it running and top up with a bit more petrol it will eventually 'flush' out the diesel?

I guess you have a plug in?

 

[timberwolf]

A 2006 Prius, if it was a plug-in it would have to be an after-market DIY.

What is meant by dead?  The HV Battery at 80% (full charge) will get you about a 1 to 1.5 miles of driving.

If you have 12V DC from the 12V battery then the car computers will boot up and switch the relays. If the car is dead that means the 12V Battery is flat/dead!

[cuius]

From the AA comments above:

" This is far less common as the diesel nozzle is physically larger than the petrol filler neck on most cars. "

How did you get the larger diesel nozzle into the filler?