[DerAlte]

Originally Posted by joybhowmik

... This is because petrol in the mix, can end up dissolving the lubrication in your fuel pump, causing metal to metal grinding together, and production of fine metal particle shards ...

Lubrication with what? Engine oil? Grease? Perhaps the fuel itself is the lubricant / coolant, no? And is diesel not a solvent?

AFAIK, there are no other organics in a fuel pump (diesel or petrol) other than a neoprene sealing ring.

Originally Posted by Jeroen

how did you determine that the damage to the fuel pump was related to petrol and not some other cause? For instance fuel contamination other than fuel? ...

Originally Posted by joybhowmik

... My earlier European car's fuel pump (Fiat Palio 1.9D 2004) did indeed succumb to damages caused due to incorrect fueling here in India ...

Originally Posted by Jeroen

Well, sometimes just inspecting the parts that broke, or in combination with inspecting other parts you can sometimes narrow down the cause. ...

Difficult to understand how, without the pump being taken apart and inspected, a conclusion can be drawn that fuel pump failure was caused by wrong fuel or impurities. It could as well have been failure due to part fatigue or unseen fault / inclusion in a cast / injection-formed part.

Originally Posted by ramzsys

That Palio Diesel had an electronic fuel pump. It was a bit 'advanced' for India, because all IDI engines usually had mechanical pumps. ...

An 'electronic fuel pump' is an electronically-controlled fuel pump, where the fuel pump is the same old mechanical pump. The control of fuel pressure (how much and when) of the fuel delivered was mechanical earlier.

Originally Posted by Jeroen

... hands on work experience in designing, building and operating ...

That, perhaps, makes the most difference, sir. University education only gives pointers / directions, and one can surely take a wrong turn somewhere despite perfect directions, right?

[joybhowmik]

Originally Posted by DerAlte

Lubrication with what? Engine oil? Grease? Perhaps the fuel itself is the lubricant / coolant, no? And is diesel not a solvent?

AFAIK, there are no other organics in a fuel pump (diesel or petrol) other than a neoprene sealing ring.

I would not be too certain of stating that for a fact. As I could not scan the pictures from my old texts, I did the next best thing - which is to provide a link from Rochester University - on the workings of a fuel pump.
http://www.cs.rochester.edu/~jag/vw/...i/injpump.html

Whilst it does not say the specific type of lubricant used for the many moving parts, it is normal for light machine oil to be used when there are small moving parts that are used for metering purposes (essential job of a fuel pump).



Diesel is not as good a solvent as petrol - main reason for this is petrol is lighter than diesel.
In fact, I have seen our friendly neighbourhood dry cleaner perform "petrol wash" of stained clothes - they don't use diesel.
So, the only point I was trying to make is that 'in case' the petrol comes in contact with the mechanical parts performing the metering function, it can dissolve out the lubricant which keeps the gears from wearing down. The question is how or why should petrol come in contact with the moving parts. There could be internal parts failure (wear and tear), the petrol could deteriorate any O ring or other sealant or gasket designed to keep the fuel separate from the lubricant.

Originally Posted by DerAlte

Difficult to understand how, without the pump being taken apart and inspected, a conclusion can be drawn that fuel pump failure was caused by wrong fuel or impurities. It could as well have been failure due to part fatigue or unseen fault / inclusion in a cast / injection-formed part.

Originally Posted by DerAlte

That, perhaps, makes the most difference, sir. University education only gives pointers / directions, and one can surely take a wrong turn somewhere despite perfect directions, right?

Its not about university education being better or worse than hands on experience.
Its about mis-fuelling and it's impact. Please do consider this link from the Automobile Association of UK.

http://www.theaa.com/motoring_advice...sfuelling.html

Now, this is a .com site, so one may say they have a commercial interest in such cases.

However, in this specific example I think we can both agree to disagree on the impact mis-fuelling can have.

[ramzsys]

Originally Posted by DerAlte

An 'electronic fuel pump' is an electronically-controlled fuel pump, where the fuel pump is the same old mechanical pump. The control of fuel pressure (how much and when) of the fuel delivered was mechanical earlier.

Yes. Palio D offered 'drive by wire', and it is the electronics in the pump, the malfunctioning of which led to it's failure. A.S.C blamed it on the 'diesel adulteration in India'. Parts arrival were late, and all this added to the company's woes.

I have seen some cars with the Lancer diesel's pump as the Fiat pump was expensive.

[DerAlte]

Originally Posted by joybhowmik

... Whilst it does not say the specific type of lubricant used for the many moving parts, it is normal for light machine oil to be used when there are small moving parts that are used for metering purposes (essential job of a fuel pump). ...

I quote a passage from the 2nd link you had provided - the UK AA link: "Diesel fuel pumps ... and are lubricated by the fuel. "

Not difficult to understand, no? One has to remember that the fuel is not being permanently changed - only contaminated by mistake. In other countries, the fuel tank lid has a rather large sticker on the inside announcing the fuel to be filled. One can't say much about a person who would make the mistake with a full tank wrong fill despite that. Not a good experience when the wrong fuel leaves one stranded, and then the hassle of draining/flushing the fuel system. But, a fraction of tank contamination will only affect performance (badly in extreme), not leave you stranded.

The rest of the text in the UK AA text is just to scare the daylight out of drivers who are not engineers. A small amount of contamination is not going to destroy the pump. "Petrol in diesel acts as a solvent, reducing lubrication, and can cause damage to the pump through metal to metal contact." Really?

Yes it would, provided you manage to run the engine on the wrong fuel for, say, a couple of 1000Km, or run the starter for the equivalent time. You are a mechanical engineer, so I don't think you need to be told petrol in diesel, or diesel in petrol will not corrode / erode the surface of aluminium and steel, nor is the minor reduction of lubrication enough to produce 'shards' in the 5-10mins that it would take for the engine to stutter and stop, and not start again. If you believe that, well ... what can one say!

Originally Posted by joybhowmik

... Diesel is not as good a solvent as petrol - main reason for this is petrol is lighter than diesel. In fact, I have seen our friendly neighbourhood dry cleaner perform "petrol wash" of stained clothes - they don't use diesel ...

Err... first time I am hearing that capability of a solvent depends on density / specific gravity, and not chemical composition and volatility. They don't use diesel because it doesn't evaporate and stays locked in the fibers, leaving a nice kerosene-y odor permanently in the garment.

And maybe you should try dissolving neoprene and butyl rubber in petrol?

Originally Posted by ramzsys

Yes. Palio D offered 'drive by wire', and it is the electronics in the pump, the malfunctioning of which led to it's failure. A.S.C blamed it on the 'diesel adulteration in India'. Parts arrival were late, and all this added to the company's woes. ...

I have heard worse explanations from clueless service center guys desperately wanting to placate a customer or seem like an expert. It is not the adulteration which kills the pump (most common adulteration is kerosene or some other cheap organic by-product). It is fine gritty stuff in the fuel that eludes the filter and grinds away the moving parts over a period of time. Of course the most common failure cause is inherent material defect in the part, not contaminants or grit.

In other countries, a failure prompts the company A.S.S. to replace a pump without delving into the sordid details of the failure with the customer. Failed? Replace it! Same thing failed twice? Call the manufacturer's guys. Simple. Wonder why in India do they have to pretend like experts. Is it customer-induced behaviour? Then we are asking for it!

And, the electronics stay outside the pump. The only link is to the final control element in the pump that the electronics control, usually a simple solenoid (the 'magnet valve' in the diagram in the Rochester University link from @joybhowmik). In Common Rail and "Pumpe Düse" (Unit Injector) systems, this solenoid is part of the injector.

[ramzsys]

Yes, the fuel(diesel) is the lubricant.

More reading: http://mbm.net.au/b100/lsd.html

[masin4]

Looks like the US president is also not immune to wrong fuel being used in his car

http://www.digitaljournal.com/article/346163

[sanyal779]

This Ford Fiesta ZXI in which petrol was filled in by mistake has shown no abnormality. The entire mix has remained in use and every time I have used the car I have closely observed for abnormality- none found. All the possible consequences discussed through various posts are very correct. But surely there is some margin of error built-in in the design to perhaps cover for small mistakes. I have driven the car on this mix oil for nearly 300km now, no abnormality noticed. Certainly petrol must not be filled into a diesel car's system, but one-off mistakes may sometimes can be forgiven. This is what I can observe.

[FlatOut]

Originally Posted by sanyal779

This Ford Fiesta ZXI in which petrol was filled in by mistake has shown no abnormality. The entire mix has remained in use and every time I have used the car I have closely observed for abnormality- none found. All the possible consequences discussed through various posts are very correct. But surely there is some margin of error built-in in the design to perhaps cover for small mistakes. I have driven the car on this mix oil for nearly 300km now, no abnormality noticed. Certainly petrol must not be filled into a diesel car's system, but one-off mistakes may sometimes can be forgiven. This is what I can observe.

As a rule of thumb, the newer the design of fuel injection system on a diesel, the more susceptible it is to running on a blend of other fuels. So a common-rail diesel is very likely to be damaged on a small percentage of petrol whereas an old-fashioned diesel with indirect injection, or one of the non-PD TDi VW group diesel engines will survive perhaps up to 20-30% petrol, if you are lucky. Modern diesels have heat exchangers for the fuel to bring the viscosity down to a given value which the pump can tolerate, suggesting that diesel which is too cold could even do so damage eventually.

Back in the 80s, diesel car owner manuals recommended up to one third petrol in very cold (sub-zero weather) to prevent the fuel from waxing. The colder the fuel, the thicker it is - so although a cold start on 20% petrol may be survived, as the pump gets up to temperature the fuel will be thinned and damage is more likely to occur, especially where there is a fuel heater as I mention above.

The cost of replacing a fuel pump and injectors on a modern diesel is very, very high! If you lend your diesel car out to anyone, be very sure they know it is a diesel!

[sanyal779]

Dear sir,
this incident is now about a 6+ months old, o not remember all details. However when it took place, I remember that I had the rest of the tank filled up by diesel fuel in order to reduce the proportion of petrol and used up the mixture. All went smooth.

I fully agree to the possible damage to the fuel pumps due to lower lubricity of petrol , fortunately that had not happened. The engine is normal. My seemingly wild experiment was successful, though I would not recommend same to anyone!!

in actual condition though, the diesel we get to use in India is not pure , it does have mixture of kerosene etc. Some experts tell this diesel is closer to the cutting oil grade. I guess the ford engine fuel pump was built with tolerance built in to accommodate that lesser lubrication. Or simply that the damage has actually taken place, but short of the failure level. No way to check.
In practice the car is running normal as before!!!

[StarScream]

Mods - I also added this post to the Street Experiences, Filling petrol in a diesel car thread. Pls remove from whichever thread is not the correct one.

This mess up is so common.

Yesterday, after leaving work, me and a colleague were going to a co-worker's party in Khan Market, when I noticed the low-fuel light and said I needed petrol. My colleague said the pump next to Taj Mansingh is a good one and we stopped there. I got off the car, left it running since my colleague was sitting inside with the A/C on, and asked the attendant to top up the tank with petrol.

He must have not heard me because he hurriedly pulled out a nozzle and started filling. 30 seconds later he must have noticed the 91/95 RON sticker on the fuel-filler cap or the nozzle didn't fit and he quietly asks me, "Is this a petrol or a diesel?" I looked at him and said "Petrol." And then realizing the import of the question, almost yelled "Why? What have you done?" He says quietly, "I've filled diesel." I asked him to stop immediately.

Hearing this commotion my colleague asked me what the issue was. I told him that diesel had been filled. He had the presence of mind to immediately tell me to stop the engine, which I hadn't realized was running because when I'm alone I always switch off the car. I did so and the fuel station guys asked me to steer the car to the side, while they push it.

Now being a DSG, I didn't know how to move it to neutral, without engine power. I know in the manual there is a section that tells you how to do this by removing the plastic surround around the gear shift. But I didn't have time with cars lined up behind me. Anyone who knows this pump, knows that it's a pretty narrow area. So I put the car on in accessory mode, being careful not to crank the engine and to my surprise the gear lever moved to neutral and the car could be pushed. We moved it to the side with some difficulty in steering it without power steering.

About 7 liters of diesel had gone in and since the reserve light had gone on fairly recently, I assumed about 7 liters of petrol was in the tank. The staff got a hydraulic jack and tried to open the tank from below.By this time, the owner of the pump, a very nice old gentleman, had noticed what was going on and asked us to wait in his office. We refused because we wanted to monitor what was going on and he waited with us.

The petrol pump guys couldn't open the tank valve and the owner sent for a mechanic from Khan Market. But it was 7 p.m. and everybody had packed off. The owner offered to keep the car overnight and get it drained the next day. I decided to give VW Roadside Assistance a try and they just offered to tow it to the nearest workshop. The owner had told me that is all VW will do, since he owns Jetta and knows how they operate.

While all this was being discussed, the staff had got a slim pipe and started to drain the tank from the inlet. They kept going for about 10 minutes and drained some 15 liters of an amber liquid, which is what happens when whitish diesel mixes with brownish petrol. Now since that is roughly what I assumed the tank had, I figured filling the tank up with petrol will sufficiently dilute any remnants of diesel.

So, I topped up the tank and filled 54.8 liters in a 55 liter tank. With some trepidation I started the car and it came to life and idled smoothly as if nothing had happened. There were no warning lights. I thanked everyone and the owner even paid me back for the 7 liters of petrol that had been ruined. I can't overstate how nice he was.

I drove to Khan, attended the party and then drove the 15-odd kms back home. No issues whatsoever. I called my VW dealer today and they asked me to bring the car in because they need to check the fuel pump and fuel filter. I'm debating whether to do that because there is no symptom of any trouble.

[Gansan]

I have a doubt. How come some petrol engines run on kerosene? Honda Gensets, for example. We have to start with petrol, then switch to kerosene. I think before stopping also one has to switch to petrol.

Many years ago when I was in school I have observed a friend's family run their Morris Minor on kerosene. I travelled with them to Mahabalipuram once. No fuel will be filled in the tank. There will be two containers inside the car, near the co-passenger's foot. One will contain petrol and the other kerosene. as soon as the car cleared the city limits, the tube will be removed from the petrol container and put inside the kerosene one. There will be some hiccup, but thereafter the car will run smoothly. A few KM before stopping, the tube will be restored to the petrol container again. The process will be repeated on the return trip as well!

[joybhowmik]

Originally Posted by Gansan

Many years ago when I was in school I have observed a friend's family run their Morris Minor on kerosene.

The Ambassador of yesteryear was okay with kerosene.
Not quite sure , why this worked , at least in the short-run?

[dass]

Originally Posted by StarScream

I called my VW dealer today and they asked me to bring the car in because they need to check the fuel pump and fuel filter. I'm debating whether to do that because there is no symptom of any trouble.

You should do this at once, remember that the car was still running when the wrong fuel was being filled, high chances that some of it would have gone to the filters. No harm in getting them changed or at the least inspected right? At least, that is what I would have done. Better safe than sorry. We are, after all talking about VW group here.

[StarScream]

Originally Posted by dass

You should do this at once, remember that the car was still running when the wrong fuel was being filled, high chances that some of it would have gone to the filters. No harm in getting them changed or at the least inspected right? At least, that is what I would have done. Better safe than sorry. We are, after all talking about VW group here.

You're right but after all we are talking about VW here. I don't want to warn them that there was ever an issue so that they can deny warranty. That is why I've hesitated to take it to the workshop.

Incidentally, I ran a full VCDS scan and there were no error codes in the fuel system or engine. The car has run about 100 kms after this incident and is fine. If there was even a hint of trouble I'd have taken it to VW. It ran only 10-20 seconds while the diesel was being filled. I don't think any of the adulterated fuel reached the fuel system.

[joybhowmik]

Originally Posted by StarScream

You're right but after all we are talking about VW here.

what's so different about VW that the ignition point would change w.r.t. TDC???

It ran only 10-20 seconds while the diesel was being filled. I don't think any of the adulterated fuel reached the fuel system.

You are on a thin line. Did you compute the fuel flow rate, whilst berating the attendant?