Unleaded petrol mixed with Diesel in a Chrysler 2.5CRD

Priming the system could cause severe damage only because the pump could be turning dry. Petrol is wet but to help it lubricate better then add a pint or so of engine oil to the tank. There should be absolutely no problem then and at the concentration suggested by the OP, no problem anyhow.

Huw

Reply to
Huw
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Yes, just add no more than a pint of engine oil to 15 gallons of fuel mix. Using ATF would even help clean the injectors.

Huw

Reply to
Huw

Priming the system, if not done properly, most certainly can ruin the pump. However, a bit of petrol will not. Much more than 40% probably would result in damage even with some lubricating oil added.

Huw

Reply to
Huw

But she has driven it home from the petrol station which was about 3 miles.

Reply to
Malc

Bugger, that's a bit late then. Oh well, the choice is yours. If you do decide to take a chance I'd highly recommend selling it soon then, if it does prove to be the worst, then you are talking a lot to fix it.

Reply to
Andy Hewitt
[Snipped Text]

You're use of 'could' and 'should' is obviously taking a slightly hesitant stance on this one.

Unless you've actually seen results of either option, then taking the safest is best IMHO. It's a bloody expensive gamble if you're wrong - and you are going against the advice of the manufacturers!

Reply to
Andy Hewitt

I wonder how much it takes to prime the system? If you'd just put petrol into a tank that still contained some diesel, then the system was primed, is it going to take in significant amounts of petrol? If you realised your error and waited a bit, would the petrol separate out from the diesel and float on the top? You could in theory then brim it with diesel and drive, very carefully, to a garage, or siphon it out.

Mind you, I rarely lock my doors at a petrol station, but I do take the keys out...usually...

Reply to
Halmyre

I think Andy Hewitt is overstating the case in rather overly-dramatic terms of imminent car death and immense repair bills. Yes, CRD fuel pumps require full-time lubrication. Yes, they're intended to pump diesel rather than petrol. But, it is simply unrealistic and unnecessarily operatic to assert that the tiniest percentage of petrol will take out the pump, destroy the engine, necessitate complete replacement of the entire fuel system, etc.

Work through the maths: The OP has stated the vehicle had 1/4 tank of diesel when his wife drove onto the forecourt. That is probably an

*indicated* 1/4 tank, which in real volumetric terms equates to more like 1/3 tank (accounting for the reserve quantity of fuel in the tank when the gauge indicates Empty). He further states his wife put in 11 litres of petrol followed by 40 litres of diesel.

Working from the 1/4-tank start (worst case), that means 40 litres diesel plus 11 litres petrol = 51 litres = 0.75 tank volume. Therefore, 11 out of

68 litres are petrol, and 57 out of 68 litres are diesel. Therefore, the tank contains -- worst case -- 16% petrol.

Working from the 1/3-tank start (best case), that means 40 litres diesel plus 11 litres petrol = 51 litres = 0.67 tank volume. Therefore, 11 out of

76.5 litres are petrol, and 65.5 out of 76.5 litres are diesel. Therefore, the tank contains -- best case -- 14% petrol.

Diesel fuel is sold all over the world. With the exception of North America, so is the CRD PT Cruiser. The diesel fuel sold all over the world is not the same. Its formula is varied to account for local climatic conditions. It is thinned considerably for cold regions, otherwise it would be unusable.

In real terms, therefore, the effect is as if the OP had bought a tankful of diesel in winter in Norway or Sweden.

Mr. Hewitt, you are making a much bigger, scarier deal out of this than it almost certainly really is.

Reply to
Daniel J. Stern

Priming 'could' I said because it won't if done properly. 'Should' be no problem because nothing is absolute. There should indeed be no problem.

CR systems are sensitive it has to be said but they are as likely to self destruct for no good reason as for any particular reason. If perchance the fuel system does break down in the future as a result of incorrect fuel use then it is likely that the damage will be covered by the cars insurance company. It is a valid claim if not specifically excluded.

Huw

Reply to
Huw
[Snipped Text]

Not sure on those in particular, but a normal fuel injection system uses a continuous flow of fuel. You have a feed to the pump, the pump feeds a common rail at constant pressure, the unused fuel returns to the tank. Obviously with the high pressures involved here, it's going to go around rather fast.

Yes, although that's probably not a good idea either!

Reply to
Andy Hewitt

Er...no. Diesel and petrol are completely miscible. No such separation occurs, no matter how long you wait.

Reply to
Daniel J. Stern
[Snipped Text]

My error, I didn't see the 'Priming' bit, sorry about that.

We've had a couple paid for by insurance so far, but my conversation with the engineers suggest they are planning to close that loophole very soon.

Reply to
Andy Hewitt

Don't get your knickers in a twist over 'priming'. The fuel system is permanently primed. The electric lift and circulation pump switches on at an early stage before cranking though. The system only ever needs a proper priming if the system has been disturbed or a fuel filter changed and more carefully after running out of fuel. In essence it is self priming by switching the electric fuel lift pump on for a while to purge the system of air by circulating fuel through the pipework and back to the tank. Specific manufacturers have various means of achieving this and some might need a further knack on the part of the mechanic. The main thing is not to crank the engine for more than a few seconds without having purged the system properly first.

Huw

Reply to
Huw
[Snipped Text]

That's OK, you can have your opinion. I'll leave you to do the experimentation.

Reply to
Andy Hewitt

The message from snipped-for-privacy@gmail.com (Andy Hewitt) contains these words:

Now there's a surprise! In the good old days it might cost a hundred to drain the tank and dispose of the waste - nowadays it's new pump, new injectors or even head - must cost thousands.

Reply to
Guy King

Having now heard the evidence from bith the the prosecution and the defence, I'm leaning towards the side of Andy's argument. It was not a question about eminent damage, but the longer term implications. Even though the car is of low value, that doesn't mean that he can just replace the car and be up and running the next day as if nothing had happened.

Reply to
Johannes

Imminent, not "eminent". And Andy claimed the damage would be severe and immediate (i.e., imminent).

Pay attention. It's a recent-model PT Cruiser CRD.

Reply to
Daniel J. Stern

Do you have an owners manual?

In every owners manual I have ever seen for diesel engines, it tells you how much of a percent of gas is allowed in the mix.

Even my Jeep owners manual specify what grade and how much if any alcohol mix is allowed in my gas. They only allow enough mix to get you to 'real' gas if you are almost out, then to dilute it as far as possible, otherwise non at all is allowed.

Your manual should say something about it.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

Reply to
Halmyre

If you read all of my replies you will not find any use of the word iminent, or any variation thereof. The consequences could indeed be severe though.

As yet I have no idea of the time scale involved, it's obviously a very large variable, and could be a matter of days, weeks, months years or never. All I have said is that it's a gamble if you go against the advice of the manufacturer. I've not even offered any opinion, just plain and simple known information.

Let's say that the OP decides to simply run the vehicle based on advice given here, and in a couple of months the pump does fail. What then? Who's going to offer to help the OP out of their predicament?

Reply to
Andy Hewitt

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