What engine damage can be caused by contaminated petrol?

[thewarlock]

Dynion Araf Uchaf said:

Also 0.093 % is less than half a litre in a 50 litre tank.

You're not wrong, but maybe check your maths 🤣

[Starfighter]

A partly blocked injector will not atomise correctly this could well wet the cylinder wall with petrol and not fully burn. The residual fuel will destroy the oil film and knacker the cylinder wall.

[520TORQUES]

Starfighter said:

A partly blocked injector will not atomise correctly this could well wet the cylinder wall with petrol and not fully burn. The residual fuel will destroy the oil film and knacker the cylinder wall.

Highly unlikely.

If you have ever worked with race engines with mechanical fuel injection systems that throw buckets of fuel in, you'll know how unlikely that is.

[cuprabob]

Starfighter said:

A partly blocked injector will not atomise correctly this could well wet the cylinder wall with petrol and not fully burn. The residual fuel will destroy the oil film and knacker the cylinder wall.

Surely if it was that bad the pre-cat lambda would trigger an engine management light.

[Starfighter]

I spent my first 20 years working in fuel system development, mainly on medium speed diesels but I know what a hosing injector looks like. One would hope the sensors would pick this up.

[S366]

Slightly off topic, but what is the incentive for a dealer to reject warranty work? I’m assuming they must have a maximum value of warranty work allowed before they are penalised by the manufacturer? Otherwise it would surely be in their best interest to undertake warranty work with the costs being covered by the manufacturer.

[cuprabob]

S366 said:

Slightly off topic, but what is the incentive for a dealer to reject warranty work? I’m assuming they must have a maximum value of warranty work allowed before they are penalised by the manufacturer? Otherwise it would surely be in their best interest to undertake warranty work with the costs being covered by the manufacturer.

I think the charge rate is less and thus not as profitable to the franchise.

[Dynion Araf Uchaf]

Warranty work has to be authorised by the manufacturer. It starts with a diagnosis and confirmation of the customer complaint. Normally this has a potential charge to the customer if the fault is not found. So a dealer may be reluctant to undertake the initial diagnosis if the customer won’t under write the diag. Especially it is an intermittent fault. However there are processes around this that can help. Generally though a dealer is happy to undertake warranty work but it has to be authorised by the manufacturer and the manufacturer will go through a process in baby steps. Even if all evidence point to a knackered fuel pump they’ll make the tech go through a load of other relevant fault finding first.

HTH

[Pica-Pica]

cuprabob said:

S366 said:

Slightly off topic, but what is the incentive for a dealer to reject warranty work? I’m assuming they must have a maximum value of warranty work allowed before they are penalised by the manufacturer? Otherwise it would surely be in their best interest to undertake warranty work with the costs being covered by the manufacturer.

I think the charge rate is less and thus not as profitable to the franchise.

But goodwill has a reputational benefit.

[Hammer67]

cuprabob said:

S366 said:

Slightly off topic, but what is the incentive for a dealer to reject warranty work? I’m assuming they must have a maximum value of warranty work allowed before they are penalised by the manufacturer? Otherwise it would surely be in their best interest to undertake warranty work with the costs being covered by the manufacturer.

I think the charge rate is less and thus not as profitable to the franchise.

When I was in aftersales management manufacturer warranty labour rate was set by matching the dealers recovery rate.

As a dealer you had to report to the manufacturer a raft of KPIs on a monthly basis. This was where the manufacturer obtained the information required to set the warranty rate.

Recovery rate is what the dealer achieves from all it`s workshop activity. The headline labour rate could, for example, be £120 ph but overall, once discounting, menu price work etc etc was taken into account the recovered rate would be lower, say £95 for every hour sold. This, then, would be the rate fixed by the manufacturer that the dealer would be paid for warranty work. This would usually be fixed on an annual basis IIRC.

Therefore the upshot was that the dealer would be paid the same for warranty work as everything else so there was no reason to not do it or prioritise other types of work.

Where warranty work was less attractive was in parts profit, where most manufacturers would only pay a very small percentage above dealer cost.

[cuprabob]

Hammer67 said:

cuprabob said:

S366 said:

Slightly off topic, but what is the incentive for a dealer to reject warranty work? I’m assuming they must have a maximum value of warranty work allowed before they are penalised by the manufacturer? Otherwise it would surely be in their best interest to undertake warranty work with the costs being covered by the manufacturer.

I think the charge rate is less and thus not as profitable to the franchise.

When I was in aftersales management manufacturer warranty labour rate was set by matching the dealers recovery rate.

As a dealer you had to report to the manufacturer a raft of KPIs on a monthly basis. This was where the manufacturer obtained the information required to set the warranty rate.

Recovery rate is what the dealer achieves from all it`s workshop activity. The headline labour rate could, for example, be £120 ph but overall, once discounting, menu price work etc etc was taken into account the recovered rate would be lower, say £95 for every hour sold. This, then, would be the rate fixed by the manufacturer that the dealer would be paid for warranty work. This would usually be fixed on an annual basis IIRC.

Therefore the upshot was that the dealer would be paid the same for warranty work as everything else so there was no reason to not do it or prioritise other types of work.

Where warranty work was less attractive was in parts profit, where most manufacturers would only pay a very small percentage above dealer cost.

Thanks for the clarification.

[FMOB]

There is a certain irony that car manufacturer wants a fancy showroom that needs a certain labour rate to support it and then doesn't want to pay the hourly rate to fix their cars under their warranty.

[evil.edna]

Starfighter said:

A partly blocked injector will not atomise correctly this could well wet the cylinder wall with petrol and not fully burn. The residual fuel will destroy the oil film and knacker the cylinder wall.

This is entirely plausible and likely. Additionally, the ECU may also increase the pulse width of that injector to balance out the mixture. This will also contribute to wall wetting.

[EUbrainwashing]

RazerSauber said:

I'd have a word with an independent inspector (Automotive Consulting Engineers are ones I've dealt with in the past) and have them come to assess your car, and get a fuel sample test done. .

Yes - thanks

The 'warranty co' are Skoda UK not some insurance backed used car extended warranty outfit

[EUbrainwashing]

FMOB said:

sounds like the injector is leaking fuel. In a petrol engine this will strip the oil from the piston to cylinder interface causing substantial damage by scraping the piston up and down the bore with no lubricant.

need to get pictures of the damage to the cylinder wall and to the piston skirt (bit below the rings), damage here is due to the loss of the oil film between the two parts.

That rings true - thanks

[EUbrainwashing]

520TORQUES said:

Did they give you any photos of the damage?

I am going to swing by tomorrow and photograph the damaged engine - it is all in bits so we should be able to see the damage

[EUbrainwashing]

520TORQUES said:

You cant physically get a diesel nozzle into a petrol cars filler neck.

The dealer's assumption is that petrol contaminated with water and diesel has been purchased

[EUbrainwashing]

Dynion Araf Uchaf said:

Warranty work has to be authorised by the manufacturer. It starts with a diagnosis and confirmation of the customer complaint. Normally this has a potential charge to the customer if the fault is not found. So a dealer may be reluctant to undertake the initial diagnosis if the customer won’t under write the diag. Especially it is an intermittent fault. However there are processes around this that can help. Generally though a dealer is happy to undertake warranty work but it has to be authorised by the manufacturer and the manufacturer will go through a process in baby steps. Even if all evidence point to a knackered fuel pump they’ll make the tech go through a load of other relevant fault finding first.

HTH

This is basically what has happened at the dealership - they have been taken step by step through a procedure and then the whole job has been thrown-out by Skoda warranty because the fuel test showed 'contamination'.

[EUbrainwashing]

evil.edna said:

Starfighter said:

A partly blocked injector will not atomise correctly this could well wet the cylinder wall with petrol and not fully burn. The residual fuel will destroy the oil film and knacker the cylinder wall.

This is entirely plausible and likely. Additionally, the ECU may also increase the pulse width of that injector to balance out the mixture. This will also contribute to wall wetting.

This is all sounding like it could be the issue

[EUbrainwashing]

Well I am going to return to the dealership and photograph the damage to the engine and I will post images here and we will see what we can see. Thanks to all contributors for their kind considerations of this issue.