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You cannot get engine oil in the diesel, its impossible. How would it get from the sump into the sealed high pressure fuel system or into the tank.
On some cars you can get diesel into the engine oil through bad design of the emmission system.
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Fuel filters left for too long can turn black, engine oil not needed.
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I had a check on the www and it does certainly appear this tandem pump can allow transfer of engine oil to the fuel and vice versa. It is a widely known phenomenon.
Not being a VAG man, and thus no experience of this, it is my guess that the driven interface of the pump to the engine is oil wet and the pump seal/gasket is failing and allowing cross contaminnation.
Someone please explain what this pump does, and is my explanation of the problem correct or at least close. Some technical detail please.
Thanks in advance
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I had a check on the www and it does certainly appear this tandem pump can allow transfer of engine oil to the fuel and vice versa. It is a widely known phenomenon.
What utter tosh. If engine oil got into the fuel it would likely as not block filters and damage injectors as well as putting the emmisions way out. If diesel gets into the sump the result is sometimes catatrophic.
No manufacturer would design such a system and no such system would pass the regulations.
Its that well known that none of the 6 diesel cars I have owned have done it.
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Never say never. I'm a fitter for volvo construction and I can say from experience it can happen. The reason why I don't think it's the high pressure pump is that unless this pump has a oil feed line at it to force the oil in then it will be doubtful. Anyone any problems with high oil consumption?
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As I understand it diesel is the lubricant in the fuel pump, that is why missfueling a car with petrol causes problems since the petrol has no (or little) lubricating properties. From your post it would appear that construction machinery has oil lubrication to the fuel pump but is this because some "red" diesel used off road is lower quality and needs the extra lubrication to prevent damaging the pump.
Comparing what can happen on off road equipment with a modern road car is not really the best comparison.
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Going back to the original post, black smoke is normally associated with either too much fuel or not enough air. I would start by looking for a split in one of the turbo/ intercooler pipes, that would also tie in with lack of power. Also check the EGR valve isn't stuck open.
As far as I know, tandem fuel pumps are only used on the VW PD diesel. They are driven off the camshaft where a faulty oil seal can cause oil contamination of the fuel. Unused fuel is then returned to the tank & eventually gets back to the fuel filter turning that black. But as GB says, the black filter may be just a red herring & the filter hasn't been changed recently. You can also get bacterial growth in the fuel tank resulting in a black slime in the filter.
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Skidpan, may I suggest that you get at least a little knowledge on this subject before making comments !
Modern common rail and the VAG PD engines use a separate HP pump usually bolted to and driven by the camshaft on the cylinder head. They are used for more than just supplying fuel pressure ( on VAG's especially ) and also supply vacuum to the servo brakes and various actuators such as EGR valves and, in VAG's, the VNT units on the turbos. They need an oil feed from the engine as the secondary uses of the pump require lubrication as diesel is definitely not wanted there. When the internal seals fail, engine oil will transfer into the return fuel feed and cause the contamination as has been mentioned in an earlier post.
And your comment on plant machinery is just as laughable as these types of engine are just as complex as a "modern road car" in some cases, even more so. The days of old, smokey Perkins or Cummings engines that "run on anything" are over ( thank god ) and the technology used in them will rival most cars on the road today.
Like I said in my first post, I have experience in VAG's for this oil-in-fuel problem and posted my advice accordingly, you however, just posted deflammitory comments on a subject you obviously have an opinion, but little technical knowledge on.
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Skidpan, may I suggest that you get at least a little knowledge on this subject before making comments !
Please do not talk down to me, just because you call yourself "The-Mechanic" does not mean you have any idea about engines. I may not be qualified but I can assure you that my knowledge and experience in the field is way ahead of most so called "Experts".
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Skidpan,
Please add some value to the discussion. I asked for some technical detail but you just dismissed my post out of hand with no supporting evidence. As for saying no manufacturer would design such a system is the true tosh here. That really is an outrageous statement.
The Mechanic at least added some technical detail, which bore out my assumption about this pump having an oil wet side and when the seal/gaskey fails it will cross contaminate.
Prove to us that it isn't this pump causing the problem, and feel free to talk down all you like.
Regards
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Simply cannot be bothered with this total drivel.
Usual case of people making up nonsense to make a posting look impressive.
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It is neither a Volvo or a VW PD! Can we get back to the problem.
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It is neither a Volvo or a VW PD! Can we get back to the problem.
Correct.
On a Mondeo the high pressure pump is in the tank, it uses diesel for lubrication.
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Just out of curiosity has anyone ever held one of these pumps in their hands? I'm going out now to check the colour of the fuel in the tank. Then build her up and go for a run to see what happens
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Just out of curiosity has anyone ever held one of these pumps in their hands? I'm going out now to check the colour of the fuel in the tank. Then build her up and go for a run to see what happens
Sounds like a plan, you could disconnect the return pipe and fill a jar with fuel with engine running, should be obvious if its oil contaminated.
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Sorry,but there is no in tank fuel pump on a 2004 diesel mondeo.The lift/suction pump is in the back of the main high pressure common rail pump.This is driven from the engine timing chain.Black fuel tends to suggest either contamination in the tank or the first signs of the main high pressure pump breaking up.Check for any metal debris/swarf in the filter.
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Sorry to go off topic but I feel I need to defend myself and the other "so called experts" here on the forums from the "spirited amateurs" with misinformed opinions.
As a fully qualified, NVQ level 3, IMI ATA registered diagnostic technician with over 28 years experience in the motor trade with many dealership and independent training courses under my belt, I feel I am entitled to call myself The Mechanic. Yes, I will "talk down" to anyone who has the audacity to suggest, at their own admission, not to be an expert who has no formal training or nationally recognised qualification, that I do not know about engines.
There are loads of "trolls" lurking on many forums who just like to express their unfounded, misinformed opinions to whoever will listen, but ultimately they are found out to know little or nothing about the subject such as in this case.
And by the way, which field are you expert in ? It's not the one down the road from my work is it ? I see they have a new scarecrow.............
Edited by The-Mechanic on 06/11/2013 at 21:37
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And by the way, which field are you expert in ? It's not the one down the road from my work is it ? I see they have a new scarecrow.............
Edited by Avant on 07/11/2013 at 23:02
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From an engineering and mechanical background with the certificates and awards to prove it, that's where from.
Edited by Avant on 07/11/2013 at 23:02
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Sorry,but there is no in tank fuel pump on a 2004 diesel mondeo.The lift/suction pump is in the back of the main high pressure common rail pump.This is driven from the engine timing chain.Black fuel tends to suggest either contamination in the tank or the first signs of the main high pressure pump breaking up.Check for any metal debris/swarf in the filter.
Well we had a 2003 Mondeo TDCi and the pump was in the tank, don't think they changed it specially for the 2004 model.
I know this because the fuel sender failed (luckily while it was under warranty. The dealer had to change the entire in-tank unit which included the pump, if we had paid the cost would have been well over £1000.
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Yep tank contaminated, going to try and get some piping tomorrow and run a feed and return line into a 5gallon jar.
Seriously guys less of the b****ing the ones here who have suggested high pressure pumps know as well as I do that it's the most plausible fault as for the ONE person who's against it I'll put it down to either trolling or it being some cub who's still in tech repeating his first year exams ;-)
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Simply cannot be bothered with this total drivel.
Usual case of people making up nonsense to make a posting look impressive.
LOL Very grown up - shown to be wrong and going off in a strop! LOL
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Simply cannot be bothered with this total drivel.
Usual case of people making up nonsense to make a posting look impressive.
LOL Very grown up - shown to be wrong and going off in a strop! LOL
Why are you laughing, have you read most of the drivvel people post on this forum.
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Simply cannot be bothered with this total drivel.
Usual case of people making up nonsense to make a posting look impressive.
LOL Very grown up - shown to be wrong and going off in a strop! LOL
Why are you laughing, have you read most of the drivvel people post on this forum.
I do read drivel - and I laugh at it.
You were shown to be wrong and went on a strop so I laughed at you as well. Sometimes we make mistakes in life, admit to them and move on.
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Ooh, are we in one of those "must have the last word" battles?
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Ooh, are we in one of those "must have the last word" battles?
Could be :)
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.
Edited by Collos25 on 07/11/2013 at 18:24
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Simply cannot be bothered with this total drivel.
Usual case of people making up nonsense to make a posting look impressive.
LOL Very grown up - shown to be wrong and going off in a strop! LOL
Why are you laughing, have you read most of the drivvel people post on this forum.
A lot of it comes from yourselve when you want to get out of a hole stop digging
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Why are you laughing, have you read most of the drivvel people post on this forum.
Well, you're doing your best to make yours heard......
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skidpan,
Let's be honest, not one of your replies has been of help to the OP. The posters replies that have at least tried to help have been met with derision by yourself and you still continue to berate them even though you have been proven incorrect. What is it you are trying to prove ? It's not a competition of he who shouts loudest, gets heard !!!!
As has been suggested, it's time to take it on the chin, get over it and move on. There's plenty of other postings on the forum that you can pick a fight on. You never know, you may one day win one......
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