Unleaded petrol mixed with Diesel in a Chrysler 2.5CRD

"Bill Putney" > wrote in message
...
> Adrian wrote:
>
>
>> ...If this is a common rail diesesl (hence CRD?) then you may very well
>> be stuffed. The lack of lubrication from petrol can very quickly kill the
>> high pressure pump.
>
> If that's the case, then let me ask the obvious stupid question: If it's a
> matter of lack of lubrication, is there some oil that could be added right
> away on a one-time basis to make up for the lowered lubrication to save
> that pump (of course without causing other problems)? It sounds like in
> reality from other posts that it should be OK anyway, but I was just
> wondering about mitigating the possibilities for damage.
>

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

"Adrian" > wrote in message
. 244.170...
> Bill Putney ) gurgled happily, sounding much like they
> were saying :
>
>>> ...If this is a common rail diesesl (hence CRD?) then you may very
>>> well be stuffed. The lack of lubrication from petrol can very quickly
>>> kill the high pressure pump.
>
>> If that's the case, then let me ask the obvious stupid question: If
>> it's a matter of lack of lubrication, is there some oil that could be
>> added right away on a one-time basis to make up for the lowered
>> lubrication to save that pump (of course without causing other
>> problems)? It sounds like in reality from other posts that it should
>> be OK anyway, but I was just wondering about mitigating the
>> possibilities for damage.
>
> Not that I've heard of.
>
> Besides, since they've driven 3 miles, it's entirely possible that the
> damage has been done - as Andy's said, even priming the system *can* cause
> the damage.

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

"Andy Hewitt" > wrote in message
.. .
> Mike G > wrote:
>
>
> Surely it's wiser to take the safe option here - especially if the
> engine hasn't been run yet. The clean and flush will offer a fully safe
> solution.
>
But she has driven it home from the petrol station which was about 3 miles.

--
Malc

"The remarkable thing about the human mind is its range of limitations."

Malc > wrote:

> "Andy Hewitt" > wrote in message
> .. .
> > Mike G > wrote:
> >
> >
> > Surely it's wiser to take the safe option here - especially if the
> > engine hasn't been run yet. The clean and flush will offer a fully safe
> > solution.
> >
> But she has driven it home from the petrol station which was about 3 miles.

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.

--
Andy Hewitt ** FAF#1, (Ex-OSOS#5) - FJ1200 ABS
Windows free zone (Mac G5 Dual Processor)
<http://andyhewitt.webhop.net/>
(updated Nov. 2005)

"Huw" > wrote:

[Snipped Text]

> > Absolutely not. We have bulletins from the manufacturers now (in my case
> > Honda) that suggest even priming the fuel system can cause damage to the
> > fuel system on the latest high pressure common rail diesels.
> >
>
> 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.

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!

--
Andy Hewitt ** FAF#1, (Ex-OSOS#5) - FJ1200 ABS
Windows free zone (Mac G5 Dual Processor)
<http://andyhewitt.webhop.net/>
(updated Nov. 2005)

Andy Hewitt wrote:
> Adrian > wrote:
>
> [Snipped Text]
>
>
>>>If that's the case, then let me ask the obvious stupid question: If
>>>it's a matter of lack of lubrication, is there some oil that could be
>>>added right away on a one-time basis to make up for the lowered
>>>lubrication to save that pump (of course without causing other
>>>problems)? It sounds like in reality from other posts that it should
>>>be OK anyway, but I was just wondering about mitigating the
>>>possibilities for damage.
>>
>>Not that I've heard of.
>>
>>Besides, since they've driven 3 miles, it's entirely possible that the
>>damage has been done - as Andy's said, even priming the system *can* cause
>>the damage.
>
>
> Yes, I was talking to the recovery chap that bought the last one in, and
> BMWs actually prime the fuel system as the doors are unlocked. Bummer!
>

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...

--
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.

"Andy Hewitt" > wrote in message
. ..
> "Huw" > wrote:
>
> [Snipped Text]
>
>> > Absolutely not. We have bulletins from the manufacturers now (in my
>> > case
>> > Honda) that suggest even priming the fuel system can cause damage to
>> > the
>> > fuel system on the latest high pressure common rail diesels.
>> >
>>
>> 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.
>
> You're use of 'could' and 'should' is obviously taking a slightly
> hesitant stance on this one.

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.


>
> 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!
>

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

Halmyre > wrote:

[Snipped Text]

> > Yes, I was talking to the recovery chap that bought the last one in, and
> > BMWs actually prime the fuel system as the doors are unlocked. Bummer!
> >
>
> 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.

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.

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

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

--
Andy Hewitt ** FAF#1, (Ex-OSOS#5) - FJ1200 ABS
Windows free zone (Mac G5 Dual Processor)
<http://andyhewitt.webhop.net/>
(updated Nov. 2005)

On Sat, 3 Dec 2005, Halmyre wrote:

> If you realised your error and waited a bit, would the petrol separate
> out from the diesel and float on the top?

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