Petrol Ruined Common Rail Diesels

The biggest problem with putting petrol into a common rail diesel is damage caused to the highpressure pump through lack of lubrication. I have never heard of a high pressure pump seize, and the chances of it seizing are slim (i'd guess about the same as a normal injection pump). Even if the pistons in the pump were to seize, all they're going to do is stick up in there bores, and stop pumping (they're driven of a cam using a roller follower). But the chance of this happening is slim, as for the bore/piston to be damaged enough to seize, is going to mean the pump has lost a lot of pumping pressure to the point the engine most likely won't run. Fair enough the pump shaft bearing might seize, but so could a normal injection pump.

The manufacturer's requirement that the complete fuel system be changed is them protecting their own arses.

The fact is, a high pressure pump that's had petrol through it, may not fail immediately (it might not fail at all), but it does have a higher risk of failing in the future. Now, if the petrol is drained out, and refilled with diesel, and the pump fails several thousand miles later, the dealer/manufacturer is going to have to honour a warranty claim, as it's highly unlikely they're going to be able to prove petrol has been through the system. By recommending that the complete fuel system is replaced, it means they're covering their own arse, regarding any future warranty claims. And they also get the benefit, that as the customer has just paid for a new fuel system, it's less likely to go wrong during the remaining warranty period. And as high pressure pumps do have a tendancy to fail anyway, they score another slight benefit.

Personally, I've drained contaminated fuel out of modern diesels, and those vehicles are still running fine. I know of one car that's had petrol drained out of it twice, and it's still running fine. Now going by manufacturer's recommendations, we should of fitted 6k worth of components to that car, so even if it seizes tomorrow, a new engine and fuel system isn't going to cost anywhere near 6k. And if it happens on the outside lane of a motorway, and it's gets shunted up the arse, that's the shunter's fault of driving too damn close to stop in time. And another thing, should an engine sieze while doing 70, it's unlikely the cars going to come to an abrupt halt. It's far more likely the engines going to self destruct and spread itself along the outside lane.

Are you suggesting that petrol might be added to your tank when you're not looking? By whom? Or have I completely misunderstood your point...

Don't the majority of cars lock their fuel caps anyway? The ones I've used with central locking all lock the flap with the rest of the car, and those that don't have a lock on the cap itself.

Presumably his idea is to prevent anyone else who may use the car from refuelling it, and making a mistake. Mike.

Mike G wrote on Thu, 8 Dec 2005 10:26:57 -0000:

As long as noone ever goes on a long trip without him (and the fuel-tank key)...

Yes, Sorry... my original post accidentally deleted when I tried to modify it. Thats a family solution for my own car ( the only Diesel) rarely borowed but vulnerable:)

My main point was " Is it safe to buy common rail diesels given that many must surely be put straight in to auction or part exchange following a mis fueling"

Given that is various statements of thousands in costs on common rail systems for replacemants. How long does that whiff of petrol last at the fuel filler neck ? and is there any test that would prove petrol has been in the tank recently? I wondered how many are sold on straight away after a misfueling , perhaps with just a quick drain of the tank and refill with diesel?

"Must surely" is pure speculation. Very few would be my estimate. If you don't wish to take the risk, buy from a reputable dealer who will give a fair warranty for a fair price, remembering that a fair number of dealers stock will have been through the same auction ring.

Huw

Yes it is speculation. However you are assuming ( Speculating) that I wish to buy :) Not so. What is your estimate of "very few" based on with the high and precise numbers the motoring organisations give for misfueling? I would speculate that human nature being what is a high number of these petrol fueled common rail diesels get sold on when future potential costs and risks are realised..... So is there any evidence of petrol having been in the diesel fuel tank as time goes by?. or a means of testing ( entirely derived from my imagination) some sort of petrol compound *sniffer* other than the human nose that could detect many months into the future that petrol has been in the tank? This is academic interest only on my part regarding this perceived vulnerability of common rail to accidental petrol fueling and I apologise for not having spelled this out more clearly.

I would write 'DIESEL' with an indelible marker on the filler cap

Rog

In news: snipped-for-privacy@individual.net, Huw scribed for want of a better word:

May I jump on your thread then and ask "Recently in my Area, a large supermarket, had it's diesel tanks refuelled by the tanker with Unleaded" Five hours later of sales, it was reported, and a sign was put up in the filling station, offering a full drain and top up of Diesel free, or if broken down, get yourself recovered and they would pay for the drain and Full tank of diesel replacement

Now on here we are told that not only should we have had a free drain of the tank and free Full tank of Diesel but we should have been offered a completely new vehicle, or at least engine and fuel system?

How many of those who filled up were passing through and would not have returned to see the sign , ended up broken down on some road in the middle of nowhere and are now paying through the nose for a knackered vehicle In retrospect how can they now go back and prove that they filled up with incorrect fuel (other than credit card receipt at the correct time of day if off course they new that it was incorrect fuel that caused the breakdown?) and their £30k Beemer is now destroyed

What a mess, I feel sure it is not as catastrophic as it is made out the pumps/injectors would still have some liquid within so would not be running dry and destroying the bearings, and when the incorrect fuel reached the piston then it would either misfire or stop, ie the pump would not then be running for more than a minute or so, without the correct lubricant

I know nothing, just interested in the debate!

If the doomsayers are correct how could a major company in the UK Get away with just offering a drain and refill when so much damage had been caused?

"Domestos" wrote >

If the car tank was less than half full at the time of refuelling with petrol then major damage could be expected and the fuel supplier will have insurance cover for such negligent accidents. Most misfuelling incidents are trivial and result in no damage because the driver realises his own mistake before driving off. Quite frankly it is difficult to mitigate against the odd f****it here and there who does not read the big 'diesel' label on the car and match it with the correct fuel pump.

Huw

Good plan. Now you have to go round all the pumps in your area with the marker pen...

If the engine in question had been started, then I think that's not unreasonable at all. I'd have said the garage has a duty of care to its customers to provide the fuel as described, and if it isn't and the customer suffers losses as a result, then they should be entitled to compensation.

If a customer had to wait around unneccessarily for the neccessary person to arrive to drain the tank, assuming they were notified before they started the engine, then, IMHO, they should be compensated for their time as well. I, anal, though, and I don't know how far the liability on the part of the garage goes. Consequential losses, AFAIK, are very dodgy legal ground. I can imagine that if the person held up missed out on a £10 million business deal as a result of the delay, he might have trouble claiming loss of earnings to that extent from the garage in question.

I think that was more likely to be a blown head/gasket - my wife's Previa did that at one time.

Thanks Moray,As usual your post is head and shoulders above the rest .. Mik