Uncle Bulgaria Posted August 23, 2016 Share Posted August 23, 2016 Grateful if there is(are) a member(s) out there who can advise me on the implications of engine oil being contaminated by diesel fuel. I've given a full description of the apparent fault and what I have subsequently found. Forum members may find my experience of interest and it might throw up information on the topic that is of interest to all as well as answering my specific problem. My base vehicle is a Ford Transit Mk 7, built around 2011, with the 140PS engine. Recently, the message information light on the display showed red and the message display said "SERVICE OIL NOW". I stopped, checked the oil level - which was full, cancelled the warning and carried on. There were no other warning displays at that time or in the subsequent days, except that the message information light was red each time I started the engine, but could be cancelled by the reset button on the indicator stalk. As the mileage was approaching 40,000, I though the indicator light might be tied to a service interval and had not been reset at the previous service. The base vehicle has a full annual service at a Ford Transit specialist service centre, the last one being in November last. I took the motorhome to the service centre, and the service adviser talked about possible excess diesel fuel in the engine oil triggering the warning and that the oil level on the dipstick was up to the maximum mark. He spoke darkly about a possible problem with the regeneration of the diesel particulate filter, when, he advised, neat diesel could be pumped into the engine sump. Anyway, after tests I was advised that no diesel was found in the engine oil and none appeared to be entering the engine sump whilst the engine was running - assessed by draining off apparently excess oil, running the engine for an hour and checking the oil level after an hour to allow oil to drain back to the sump before and after the test. To be fair to the garage they had an open door to suggest an oil change as a precaution but did not so advise. I've now done some 400 miles since with no perceptible change in the oil level as measured on the dipstick (measured cold and in the morning). Since this incident I've tried to figure out what might have caused an apparently full sump, when I know that when I check the oil level (around every 1000 miles on long trips) the dipstick reading is about 80% between the min and max positions, and the engine uses very little oil between the annual services, covering around 8000 miles in the year. My first thought was that age was getting to me and I had a senior moment and topped up the oil level after our spring trip to the Algarve and had overfilled the sump - but the 1 litre bottle of engine oil I carry was full and unopened. I've done a few sums on the amount by which engine oil expands when hot. My sump holds 6 litres, and at oil change I assume the oil is at an ambient temperature of around 20 degC If the engine oil gets to 100 degC when the engine is hot, the original 6 litres could expand by 0.34 litres. The volume represented by the min to max marks on the oil dipstick is 1.5 litres, so the volumetric expansion of the engine oil when hot is approximately 23% of the range covered by the dipstick. So if the dipstick reading is 80% when the engine (and oil) is cold, it could read just over 100% when the oil is hot. So it appears I have had a no-fault problem, although the reason why the message information light came on has not been explained. The diesel particulate filter was a red herring - my vehicle does not have one - just a catalytic converter bolted straight onto the exhaust outlet from the turbocharger. I've checked under the vehicle and there is no sign of a DPF. Also the Owners Handbook makes no reference to a DPF neither does the instrument cluster include the symbol for a blocked DPF (this does assume the correct Handbook came with the vehicle). I understand that engine oil can become contaminated and diluted by diesel for various reasons - the DPF may be one as can a leaking injector or poor injector spray pattern and over-fueling under normal operation. But if diesel fuel does get into the engine sump is the operating temperature of the oil and within the sump enough to cause the diesel to evaporate or does it mix with the oil and gradually reduce its lubricity and result in more rapid wear of engine components and a gradual apparent rise in the oil level in the sump? Is there a simple test for diesel in engine oil - like there is for checking for water content of brake fluid? Hope folk find this saga of interest and make me and others I hope more aware of the possibility of diesel fuel getting into the engine oil. Grateful for any clarification on this rather complex subject. Link to comment Share on other sites More sharing options...
witzend Posted August 23, 2016 Share Posted August 23, 2016 There can be disastrous consequences to diesel in a engine sump. A few years ago I was on a fore court filling my car with fuel and saw a chap with an old VW golf talking to a mechanic I went to till paid for my fuel when walking back the VW owner revved his engine to further explain his problem it just carried on gaining speed the owner left it the mechanic came around the car but before he could do anything there was a large bang and clouds of black smoke. I found out later the engine had a large amount of diesel in the oil and the high level allowed the engine to feed of it over revving and a connecting rod broke and came out thru the engine Link to comment Share on other sites More sharing options...
euroserv Posted August 23, 2016 Share Posted August 23, 2016 I am sorry, I don't get it. At no point have you said that the oil level was higher than the maximum mark. Why do you think that you have diesel getting into your oil? It seems likely that the service indicator was not reset at your last oil change, and this was probably because your annual service will never coincide with the mileage stipulations and the garage didn't deem it necessary for you. Link to comment Share on other sites More sharing options...
Robinhood Posted August 23, 2016 Share Posted August 23, 2016 ...that message is usually a symptom of the service indicator not having been reset at last service. It can be self-reset on the transit by use of the ignition switch and a combination of moves on the pedals -- Google should provide the answer. The "diesel in oil" theory is (IMO) a complete red herring, particularly as you don't have a DPF (and therefore no regen). Link to comment Share on other sites More sharing options...
Billggski Posted August 24, 2016 Share Posted August 24, 2016 Diesel in the oil can happen if your piston rings are worn and the fuel gets past them. Older diesels are particularly vulnerable, the remedy is to block off the air intake if the engine runs away. Link to comment Share on other sites More sharing options...
Uncle Bulgaria Posted August 24, 2016 Author Share Posted August 24, 2016 euroserv - 2016-08-23 5:10 PM I am sorry, I don't get it. At no point have you said that the oil level was higher than the maximum mark. Why do you think that you have diesel getting into your oil? It seems likely that the service indicator was not reset at your last oil change, and this was probably because your annual service will never coincide with the mileage stipulations and the garage didn't deem it necessary for you. Sorry for confusion. Let me try to clarify. When the warning indicator came on I stopped and checked the oil level. The dipstick reading was at the full mark. At the time, of course, the engine was hot having been running for a couple of hours. I normally check the oil level with the engine cold, and the dipstick reading is normally around 75% of the scale. The apparent increase in oil level didn't concern me at the time and I assumed that the warning was associated with the approaching 40,000 miles, which is the mileage for a major service, and that the system had not been reset at the previous service, as Euroserve and others suggest. It was when I took the motorhome to the local Ford Transit service centre and explained the recent event that they suggested an increase in oil level might indicate that diesel was getting into the oil. This is known to happen and can be catastrophic. As it turns out, no ingress of diesel into the sump could be found. So why was the oil level higher than normal when I checked it at the roadside? A few sums suggest the volumetric expansion of engine oil between hot and cold states could account for the apparent increase, and since there has been no change in the cold oil level measured on several occasions over the past 400 miles suggest that it was a false alarm, but I will continue to monitor the level before the start of each journey. Hope this clears things up. Link to comment Share on other sites More sharing options...
aandncaravan Posted August 27, 2016 Share Posted August 27, 2016 The vehicle must be absolutely level when you check the oil other wise a slight 'tilt' down towards the Dipstick will give an artificially high reading. Just a very small incline can sometimes be enough to change the Dipstick level by a few millimetres. If your Drive, or the place you normally check the Oil, slopes one way and the slight angle of the road side went the other, it could give quite a marked difference? It may be a bit over the top for some, but you seem to be very particular on the height at which you maintain the Oil level, in my opinion to your advantage. So maybe keeping a small portable Spirit level, like a Caravan leveller, stuck somewhere under the bonnet as a guide might assist? They are only a few pounds and some self adhesive. We wish more people would use them as an overfilled sump, from the vehicle not being level, is quite common. An overfull sump can have quite an impact on fuel consumption as well as risk engine damage. I agree with the others that Diesel in the Oil on a modern van is a Red Herring. Link to comment Share on other sites More sharing options...
hallii Posted August 28, 2016 Share Posted August 28, 2016 The dip stick on these engine are not easy to read. The oil seems to pull up the stick as it is removed and gives a false reading, it will do that no matter how many times you wipe the stick. To check the level, pull the stick out and leave it overnight, in the morning dip the oil and you will get a proper reading. You only get one chance!! I measure the oil when I do my oil change and since I don't use any oil I forget it until the next service. H Link to comment Share on other sites More sharing options...
Will86 Posted August 29, 2016 Share Posted August 29, 2016 UB The end of your message comments "Hope folk find this saga of interest and make me and others I hope more aware of the possibility of diesel fuel getting into the engine oil. Grateful for any clarification on this rather complex subject." UB ... Stop dreaming up problems. Its not a saga, its not a complex subject, its oil doing what it was designed to do by being spread around the working parts. When an engine stops and the pressure has reduced the oil takes time to settle back to where it should be and not still running down your dip-stick giving you false readings (according to you). If the oil level had been where you expected it to be then you would possibly have has a seizure as no oil would have reached the moving parts. Link to comment Share on other sites More sharing options...
Uncle Bulgaria Posted October 17, 2016 Author Share Posted October 17, 2016 Having started this thread I thought I should close it out by thanking everyone who contributed comments and giving an update. I've driven some 2500 miles since the original post, mainly to Spain and back, and with careful monitoring of the oil level have found no increase in level and a negligible drop. So the service warning indicator was a red herring. hallii made a very useful comment (as he also has a Transit based vehicle). Getting an accurate oil level measurement on the dipstick is difficult on the Transit - the oil seems to wick up the inside of the dipstick tube even when standing, and with a hot engine it is almost impossible. I've also had a call from the service manager at the Ford garage who advised that if the mileage and time is not within the range the vehicle's computer expects since the prior service then the service reset does not always work (or if I was cynical the technician forgot to do it!). Many thanks. All's well that ends well. Link to comment Share on other sites More sharing options...
Will86 Posted October 17, 2016 Share Posted October 17, 2016 the oil seems to wick up the inside of the dipstick tube even when standing, and with a hot engine it is almost impossible Yes ... so ...! Link to comment Share on other sites More sharing options...
witzend Posted October 17, 2016 Share Posted October 17, 2016 Billggski - 2016-08-24 12:56 PM Older diesels are particularly vulnerable, the remedy is to block off the air intake if the engine runs away. A lot easier said than done, I'm afraid it would be to late by the time you where able to block the air intake this one took 30 secs to blow the noise and smoke was frighting really. Link to comment Share on other sites More sharing options...
Archiesgrandad Posted October 17, 2016 Share Posted October 17, 2016 If you get the chance you can stop a runaway diesel by squirting a CO 2 extinguisher into the air intake. It will do no damage. AGD Link to comment Share on other sites More sharing options...
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