Help please! Contaminated Fuel 2021 E300 Coupe

[tonysmb]

The sudden noise was probably that of an internal engine component or the pump failing.

With the greatest of respect, how experienced a driver is your partner, as I know some people who simply wouldn't notice or be aware of a change in engine behaviour, ie rough running, loss of performance etc. until such time as it 'fails to proceed'. I'm not suggesting, by any means, that this was a factor, simply stating my experience. What did she/he drive prior to this one?

Bellow's point, post #40, is relevant, particularly on a modern electronically controlled engine, which is very different to the older pre-emissions engines.

Whilst some people can be critical of main dealers (and I've had my own issues with some, including one MB dealer), I really can't see that the dealer in this case would 'plant' diesel in the tank. As I understand it, there does not appear to be any benefit to them, there can be no suggestion that they could have had any connection to the failure as they didn't even pdi the car and only saw it after the engine failure. Who did pdi the car?

Replacing the engine etc is not a particularly difficult job for them. If the car had half a tank of fuel when it failed, I can't think of any reason why they would add a can of diesel, it just doesn't seem logical.

Has your partner been the only driver and refueller, ie not lent it to a colleague for a trial run and they helped out by replacing a gallon of fuel? Has it been left with anybody, even for a short time, for any reason whatsoever, ie car detailer etc etc..

It really does seem as if there is / has been diesel in the fuel system, confirmed by the RAC.

IF, and it's a big if, you can prove that the car has not had diesel put in the tank since you've had it, the lease company might be able to apply leverage on the delivery company, but it's a (very, very) long-shot. With the time delay, a fuel sample from the fuel station is unlikely to be conclusive due to subsequent deliveries but a request on social media for any similar incidents locally, without naming the garage as they may well be completely innocent, might produce others in your locality who have had similar issues in the same time period.

It isn't impossible to misfuel cars, whatever the delivery company and others might say, but it is more difficult than it used to be. Where there's a will etc..

It's extremely unfortunate and a very difficult situation with no easy answer but I can't see that any negative comment can be directed towards the main dealer.

 

[Bellow]

In terms of the noise, it started on the motorway and my partner pulled off immediately. Prior to this there was zero indication that there was anything wrong with the car - ran like a dream from delivery through 2 full tank refuelling's and 7 days after the last refuelling.

I think we can rule out any mis-fuelling by the delivery driver.

 

[Bellow]

Has your partner been the only driver and refueller, ie not lent it to a colleague for a trial run and they helped out by replacing a gallon of fuel? Has it been left with anybody, even for a short time, for any reason whatsoever, ie car detailer etc etc..

This.
I think zoning in on events much closer to the fateful occurrence is required. That it ran fine for seven days after its last re-fuelling kinda knocks that fill out as being suspect. A malicious actor at play?

 

[Teego]

It seems to me that the true answer will only be found after a full engine teardown witnessed by an independent chartered engineer. Time to find a lawyer.

 

[mioba]

This.
I think zoning in on events much closer to the fateful occurrence is required. That it ran fine for seven days after its last re-fuelling kinda knocks that fill out as being suspect. A malicious actor at play?

good point Watson.
Could an unruly jealous person be envious of your shiny new car....

 

[dallman]

I think we can rule out any mis-fuelling by the delivery driver.

I agree but I will definitely be seeking evidence from them to rule this out.
My partner luckily has every journey recorded on Quickbooks as it tracks business mileage (we’ve just remembered) so it will be really simple to evidence mileage and journeys.

This.
I think zoning in on events much closer to the fateful occurrence is required. That it ran fine for seven days after its last re-fuelling kinda knocks that fill out as being suspect. A malicious actor at play?

the car took almost seven months to arrive and was a real treat and dream car for my partner so it never left our sight!!

 

[mioba]

It seems to me that the true answer will only be found after a full engine teardown witnessed by an independent chartered engineer. Time to find a lawyer.

A lawyer for what. there is zero evidence of where the diesel came from. On the balance of probabilities at this stage there is nothing to go by

 

[markjay]

The RAC went out to it yesterday and confirmed that there is Diesel in the tank. There were no errors or warnings on the Dash just making an almighty noise.

Do you have the RAC report, and did you speak directly to the person who examined it?

This reminds me of a report from the fire brigade stating that a fire started when a lead-acid battery overheated. A forensic investigator appointed by our insurer however concluded that the fire started due to a design fault in a piece of electrical kit. After investigation, it turned out that the fire brigade outsourced the investigation to a contractor, who phoned-up the equipment manufacturer and asked them why the fire started, then wrote down in the report exactly what they told him.

It would be interesting to know if the RAC tech actually siphoned a sample of the fuel from your car's tank and tested it, or simply had a quick chat with the service manager at the dealership.

And, did you see the actual lab report from the dealership?

I am thinking that given the be sums involved, perhaps it is worth your while to employ the services of a professional forensic examiner and agree with the dealership on a thorough joint examination, carried-out to scientific standards.

 

[markjay]

Also, what does the Mercedes me app show? It will pick-up any refuelling, even if done from a can. If the car was indeed last refuelled 7 days prior, then keep a screenshot as proof that no fuel was added since.

 

[markjay]

yeah that's what its looking like...The fact that the car drove like a dream up until that day and even on the morning (my partner had driven it to a clients a good 45 minutes away and it was completely fine) makes me question if the diesel was present as everyone I've spoken to has said it wouldn't be possible to drive without some indication that something wasn't right with it.

I am not a chemical engineer, but if two liquid substances don't mix well, then one will float on tbe top of the other, in which case a delayed reaction is not impossible.

 

[Fastcar155]

Hi , really sorry to hear about your problem.

My 2016 C207 has a lockable fuel flap.

Does your car have lockable fuel flap ? If your car was locked the fuel flap would be locked. Is your fuel flap damaged as it would have been to force entry.!

If you don't lock your car your are in a difficult position.

Lets say you have locked your then your car has suffered vandalism.Go to the police and report fact and obtain a crime number.

I would then report the fact to your motor insurance company.

Let them handle the case.

 

[markjay]

Hi , really sorry to hear about your problem.

My 2016 C207 has a lockable fuel flap.

Does your car have lockable fuel flap ? If your car was locked the fuel flap would be locked. Is your fuel flap damaged as it would have been to force entry.!

If you don't lock your car your are in a difficult position.

Lets say you have locked your then your car has suffered vandalism.Go to the police and report fact and obtain a crime number.

I would then report the fact to your motor insurance company.

Let them handle the case.

Given that it's either misfeulling, or mechanical failure, it does not seem to be an event covered by motor insurance policy?

It's a bit far-fetched to claim that a vandal deliberately added diesel to the tank while the car was parked-up overnight, I think.

 

[dallman]

Also, what does the Mercedes me app show? It will pick-up any refuelling, even if done from a can. If the car was indeed last refuelled 7 days prior, then keep a screenshot as proof that no fuel was added since.

Do you know where this can be found on the Mercedes me app?

 

[Teego]

A lawyer for what. there is zero evidence of where the diesel came from. On the balance of probabilities at this stage there is nothing to go by

Eveyone is getting distracted by the diesel. This is not likely to be the cause of a catastrophic failure. Certainly wouldn't explain swarf in the sump. Where did that come from?
Until the motor is stripped no-one will know the cause. Problem is, who pays?

 

[Fastcar155]

Given that it's either misfeulling, or mechanical failure, it does not seem to be an event covered by motor insurance policy?

It's a bit far-fetched to claim that a vandal deliberately added diesel to the tank while the car was parked-up overnight, I think.

Hi , well other members have suggested that very thing. If you have a comprehensive motor policy vandalism should be covered.

The OP may find that when an Insurance company becomes involved the doors that were closed may be opened.

 

[markjay]

Do you know where this can be found on the Mercedes me app?

I know where it is on my app, but I have the Mercedes me Adapter app, which is different to yours - someone with the newer Mercedes me 2020 app might be able to provide this info.

 

[cynical]

My dad used to move cars as a retirement job including mercedes from Immingham which were either bought online or leases taken direct to the customer or taken to a dealer when it wasn't worth putting them on a truck. The pdi was done by mercedes at the port. Moving mercedes wasn't allowed by anyone, they had to have extra training. For example they weren't allowed to drive at over 60mph. It used to annoy my dad as the port workers would often be young lads bringing them around 'on 2 wheels' then he had to do 60 on the motorway. They had to inspect all cars at pickup and report damage. Any damage found when they dropped off was the responsibility of the car moving company and the driver suffered a penalty. The cars always came with no fuel and they sometimes struggled to make the nearest fuel station. They were also criticised for putting any more than necessary in to get it to the customer. They wouldn't have cans of fuel as the drivers had to walk or use public transport to get to their next job and there is no reason for them to take 20 litres of petrol under one arm and 20 litres of diesel under the other just incase. The only reason I can think of is if they did infact run out on the way and a recovery company appointed by the car moving company, or a drivers mate so he didn't have to admit running out, came out to get them going.

A friend put a full tank of petrol in a diesel Nissan, drove from London to Manchester fine, when he next went to it it wouldn't start. The aa identified the fault, swapped the fuel and he was on his way. After an investigation with the petrol station their explanation was someone had swapped the nozzles on the pump leading him to pick up the wrong one.

From a bitter history I have a complete downer on the ability of all main dealers and wouldn't even used them to change an air freshener so I'm kind of biased, perhaps unfairly in some cases. But I find their report nonsense. Diesel might damage a fuel pump, but I can't see visible swarf getting through an injector. I can't see what it would do to the actual engine. I had a vito on hire to 4 months and due to the regen that thing had more diesel in the sump than oil. The hire company got me to take it to kwik fit to have the oil level dropped so it could carry on filling with diesel. It had a happy 20k on the clock without a single service. Intact I used to do offroading as a hobby and would often get water in fuel or direct into the engine, dust and grit in the engines and they worked a treat. Saying it needs a complete engine is just typical dealer parts fitter mentality.

If its on finance the first thing I would do is inform the finance company, they have a lot of leverage and its surprising what they can make happen when you've been told its impossible.

If you can I would get it to an actual specialist or real mechanic. I would ignore the rac report as they won't have dismantled the engine. It doesn't look like they're going to help you so it'll cost you less and might give you some evidence for any claim you might wish to make against mercedes.

 

[Gazwould]

A complete nightmare .

Someone is lying .

I smell Mercedes manure...

 

[dallman]

My dad used to move cars as a retirement job including mercedes from Immingham which were either bought online or leases taken direct to the customer or taken to a dealer when it wasn't worth putting them on a truck. The pdi was done by mercedes at the port. Moving mercedes wasn't allowed by anyone, they had to have extra training. For example they weren't allowed to drive at over 60mph. It used to annoy my dad as the port workers would often be young lads bringing them around 'on 2 wheels' then he had to do 60 on the motorway. They had to inspect all cars at pickup and report damage. Any damage found when they dropped off was the responsibility of the car moving company and the driver suffered a penalty. The cars always came with no fuel and they sometimes struggled to make the nearest fuel station. They were also criticised for putting any more than necessary in to get it to the customer. They wouldn't have cans of fuel as the drivers had to walk or use public transport to get to their next job and there is no reason for them to take 20 litres of petrol under one arm and 20 litres of diesel under the other just incase. The only reason I can think of is if they did infact run out on the way and a recovery company appointed by the car moving company, or a drivers mate so he didn't have to admit running out, came out to get them going.

A friend put a full tank of petrol in a diesel Nissan, drove from London to Manchester fine, when he next went to it it wouldn't start. The aa identified the fault, swapped the fuel and he was on his way. After an investigation with the petrol station their explanation was someone had swapped the nozzles on the pump leading him to pick up the wrong one.

From a bitter history I have a complete downer on the ability of all main dealers and wouldn't even used them to change an air freshener so I'm kind of biased, perhaps unfairly in some cases. But I find their report nonsense. Diesel might damage a fuel pump, but I can't see visible swarf getting through an injector. I can't see what it would do to the actual engine. I had a vito on hire to 4 months and due to the regen that thing had more diesel in the sump than oil. The hire company got me to take it to kwik fit to have the oil level dropped so it could carry on filling with diesel. It had a happy 20k on the clock without a single service. Intact I used to do offroading as a hobby and would often get water in fuel or direct into the engine, dust and grit in the engines and they worked a treat. Saying it needs a complete engine is just typical dealer parts fitter mentality.

If its on finance the first thing I would do is inform the finance company, they have a lot of leverage and its surprising what they can make happen when you've been told its impossible.

If you can I would get it to an actual specialist or real mechanic. I would ignore the rac report as they won't have dismantled the engine. It doesn't look like they're going to help you so it'll cost you less and might give you some evidence for any claim you might wish to make against mercedes.

Definitely a good point about the finance, it’s a Mercedes Finance Lease so will be in touch with them to see what they can do

 

[geoffus]

Diesel in petrol has the potential to do a lot of damage. It lowers the octane rating to the point where detonation is probable and likely severe. This can destroy pistons in short order if not suppressed. Suppression strategy would be to reduce boost (on a forced induction engine) and retard ignition timing (to the detriment of exhaust valves). Pre-ignition (HCCI) is also possible and would cause intolerable pressure in the cylinder before TDC.
If diesel contamination has wrecked this engine it will be through detonation and/or pre-ignition. That the noise was at its worse during acceleration and power dropped supports a detonation and/or pre-ignition diagnosis. The forces are sufficient to overload the oil film in the bearings and the side thrust on the piston during significant pre-ignition will destroy the oil film there also.

If there was diesel there that is.

This is the best explanation of what will happen if it was misfueled, I would have thought 20% wouldn’t have caused that much damage though unless it was more than 20% initially and diluted again with more petrol. I think someone maybe has misfueled and the engine called quits.
hopefully not the case.