Bowie69 Posted May 22, 2011 Share Posted May 22, 2011 Have you run it from a jerry can with new hose straight to the injection pump? Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 23, 2011 Author Share Posted May 23, 2011 Sorry, didn't mean to be condescending! It's just that the gauge of what is "blue" is very subjective. If it is mostly white then the diagnosis it's back to fuel (although there's nothing to say that there may not be multiple things at play ), so as others have said an incomplete burn in a particular cylinder(s) fits well. Agreed!! Garage suggested three tests all from cold cold - so can't do all at once - then to consider short list of probables. 1. Start engine and leave to idle for 15 mins to see what effect when proceeding to normal daily drive. Did this - idled for 15 mins - gauge still cold - then manouvred as usual running engine 1000 - 2000 rpm...... Result: No smoke! Well that's a result but what does that say?! 2nd test - Determine port temperature of each of 4 cylinders at continuously for 10 min warm up when symptoms are showing - to do tomorrow. 3rd test - Bring back for cold cold compression test Quote "Have you run it from a jerry can with new hose straight to the injection pump?" No I haven't. Having just refurbed the pump and injectors tested I'd be a bit worried about ingress of foreign debris directly into the pump. Why, what's your thinking? Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 23, 2011 Author Share Posted May 23, 2011 Thanks Phil for sourcing data to answer Chris' question: So diesel's flash point is at 62 degrees C with a self ignite point of 210 degrees. Soooh - I'm not reaching flash point temperature on one or more cylinders at cold start and for further 10 mins there after - right? Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted May 23, 2011 Share Posted May 23, 2011 Why, what's your thinking? It would eliminate any air getting into the system via drainback to the tank overnight, by all means stick an inline filter on the pipe if you are worried about debris Quote Link to comment Share on other sites More sharing options...
Bullyjohn Posted May 23, 2011 Share Posted May 23, 2011 Paul, the three suggestions are good ones, as is the running from a jerry can proposal. ( make sure you raise up the can and pipe to prevent drain back obviously) . I am keen to know how you get on with these.. How do your garage intend to monitor the port temps - Hand on the manifold or something more sophisticated? One more question I have for you.. When did this behaviour start and was anything done/changed just before your problems began? might offer a clue as to root cause... Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 23, 2011 Author Share Posted May 23, 2011 It would eliminate any air getting into the system via drainback to the tank overnight, by all means stick an inline filter on the pipe if you are worried about debris ok nice one - on the list to do! Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 23, 2011 Author Share Posted May 23, 2011 Paul, the three suggestions are good ones, as is the running from a jerry can proposal. ( make sure you raise up the can and pipe to prevent drain back obviously) . I am keen to know how you get on with these.. How do your garage intend to monitor the port temps - Hand on the manifold or something more sophisticated? One more question I have for you.. When did this behaviour start and was anything done/changed just before your problems began? might offer a clue as to root cause... I've borrowed their hand held digital thermometer (snap-on I think) and the missus is going to write down my temperature shouts for pots 1,2,3,4 repeatedly for 10 mins or until we see big differential. Doing this tomorrow am. Historically it just seemed to start. I don't recall doing anything other than removing EGR around or a little before. Think I would have twigged if it had started as result of that work. Probably been smoking for 2 years but not for such a duration - much greater smoke volume and for longer more recently. Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 24, 2011 Author Share Posted May 24, 2011 Engine started from cold and left idling for 15 mins. No smoke! Glow plugs re-checked thoroughly - relay checked, voltage at glow heads checked, Glows removed and checked - all okay - definite glows! Exhaust port exit temperatures checked - all seems okay (file attached) Set at fast idle 1500 rpm care of a wedge of timber! Smoking and missing Each cylinder warming up in line with the others and no real disparity of temperature. Last readings taken as cockpit gauge reaches quarter warm say 5 - 10 mins smoking stopping Quote Link to comment Share on other sites More sharing options...
western Posted May 24, 2011 Share Posted May 24, 2011 number 1 is consistently lower than the others, but that could be down to the airflow from the cooling fan across the temp tester sensors during the checks are the valve caps all in place & valve clearance correctly set. might be worth working through this diagnosis chart too Quote Link to comment Share on other sites More sharing options...
Tanuki Posted May 24, 2011 Share Posted May 24, 2011 What are the compression-pressures on all the cylinders? Can you swap out the injector on #1 cylinder with a known-good injector (either new, or from another engine) ?? --Tanuki "One winter's day the Buddha was walking trough the forest when he came upon a little weasel, half dead from cold, lying in the snow. Picking up the weasel the Buddha tucked it into the lining of his warm coat and carried it home to his wife, who baked it into a tasty pie. At that moment the Weasel was enlightened" Quote Link to comment Share on other sites More sharing options...
Bullyjohn Posted May 24, 2011 Share Posted May 24, 2011 Paul, the temps you have logged are all for the idle part or do they cover the 1500rpm raised idle as well. They look a little lower on cyl 1 but it is increasing so on the face of it they are all firing to some degree. The misfire is it regular (the same cylinder) or random ? I know its sometimes difficult to say..Did the misfire seem evident at idle or just when you raise the revs to 1500rpm? Coming back to the history - if you have changed nothing to promote the issue / for example fuel filter/injector changes etc etc - then you are left with a deterioration type root cause I would suggest.. The items like mis-timing would be associated with a belt change - and if you didn't do this or something similar prior to the smoke issue then you can rule it out I would suggest.. That leaves: oil leaks / low compression when cold (both wear mechanisms), potentially the air ingress into your low pressure fuel lines ( jerry can test) cylinder head crack ( hopefully not)and possibly some others I can think off right now.. The simplest one to fix probably is the low pressure fuel system with air getting in... - alternative to the jerry can test is to fit some clear tubing to your HP pump feed - allows you to watch for air bubbles as you run !good luck with the next tests...!! Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 25, 2011 Author Share Posted May 25, 2011 What are the compression-pressures on all the cylinders? Can you swap out the injector on #1 cylinder with a known-good injector (either new, or from another engine) ?? Hi Tanuki: We have done a compression test, the actual values I do not know but according to the graph shown in manual they were all well with the 'good compression' range and indicated no worn cylinders or valves. However, firstly the tests (through injector ports) were not done at cold,cold but after the engine had been run a little - so that's why it's going to be done again. Secondly the 'okay range' that I eluded to is very narrow at the cranking or idle speed - will discuss with garage when test is re-done. We have already swapped out a complete set of injectors before mine were sent away for testing. Admittedly the alternative set came from a vehicle that has done 180,000 miles, against mine of 85,000, but that Disco does not billow white smoke like mine - so a satisfactory test done - good shout though! Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 25, 2011 Author Share Posted May 25, 2011 number 1 is consistently lower than the others, but that could be down to the airflow from the cooling fan across the temp tester sensors during the checks My thinking too! - also if one cylinder was actually not firing during the cold start up the temperature differences would be much greater between it and the other cylinders and would not consistently increase. I also think that as proper combustion took over there would be a sudden jump up in temp. are the valve caps all in place & valve clearance correctly set. I asked for this to be checked and for the valve clearances to be done - they have been was the reply - I will check might be worth working through this diagnosis chart too ok - printed out - thanks Ralph Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 25, 2011 Author Share Posted May 25, 2011 Paul, the temps you have logged are all for the idle part or do they cover the 1500rpm raised idle as well. They look a little lower on cyl 1 but it is increasing so on the face of it they are all firing to some degree. The misfire is it regular (the same cylinder) or random ? I know its sometimes difficult to say..Did the misfire seem evident at idle or just when you raise the revs to 1500rpm? Coming back to the history - if you have changed nothing to promote the issue / for example fuel filter/injector changes etc etc - then you are left with a deterioration type root cause I would suggest.. The items like mis-timing would be associated with a belt change - and if you didn't do this or something similar prior to the smoke issue then you can rule it out I would suggest.. That leaves: oil leaks / low compression when cold (both wear mechanisms), potentially the air ingress into your low pressure fuel lines ( jerry can test) cylinder head crack ( hopefully not)and possibly some others I can think off right now.. The simplest one to fix probably is the low pressure fuel system with air getting in... - alternative to the jerry can test is to fit some clear tubing to your HP pump feed - allows you to watch for air bubbles as you run !good luck with the next tests...!! Hi Bully.... All temp readings were done from cold and whilst running at 1500 rpm. Only for the last 2 or 3 reads did I drop to idle and then blip the throttle a bit. I wanted to have the misfire and smoke problem occuring as the readings were being taken. I would say the misfire was regular ate the higher rev range of 1-2000 rpm and definitely at 1500 - 1800. Not at all at idle or past 2,200 rpm which is why I was thinking of some sort of CSD (cold start device) over doing its thing. I have read on this forum about the mechanical CSD devices: Extracted: "On a Bosch VE type pump, a manual cold start device advances the injection timing at idle and during low-speed running. A lever turns a cam that pushes the hydraulic piston to the left, advancing injection timing about five degrees. This injection advance provides more time for the fuel to burn, which improves performance and prevents smoking during cold starts and warm-up. However, above 2200 RPM the piston operates normally and does not contact the cam. There are different types of automatic CSDs (cold start devices) available for the VE injection pump. " But since being overhauled the Bosch men say there isn't one on the R509 on the 300 tdi - who am I to argue - still it does still feel like a dodgy cold start device ballsing up the fueling or timing for that period of warm up. I mean it would account for the missing as well - no engine on enrichment sounds even does it! The timing belt has just been changed (85,000) as a precaution and to eliminate stretch etc. The last one was done at 55,000 miles. I like the idea of clear fuel tube to see what's going on as whilst I have a Jerry can and some diesel I have yet to source some tube and an in-line filter - so whichever comes first. For now if I stay in a Travelodge I'll get up in the morning and leave her to idle for 15 mins before pulling away - you should see those faces!! PS: One thing I did notice when I rechecked the Glows yesterday was that number 3 had a neat ring of engine oil (see pic) when the others were dry. Now seeing that it was removed before starting wouldn't that be seeping from the valves? Edited to add Forum Reference: linky Quote Link to comment Share on other sites More sharing options...
Bullyjohn Posted May 28, 2011 Share Posted May 28, 2011 Hello Paul, the fuel pump will need to be giving some extra fuel and some advance for good cold combustion to be achieved. I have some knowledge of Vp pumps - which I think are the generation after yours - these have electronic advance and quantity control. I think the phrase you have found means the pump has a simple thermostatic advance mechanism. Obviously could go wrong - do you know if it was specifically checked cold - I doubt the dealer would be able to do this - I would guess they just have an overcheck of quantity and timing at warm/hot conditions..? I am not sure if you can buy the advance mechanism seperately - probably not. The stem seals look like a worthy change - not sure how much this will cost you in time/$.. As you have noted the oil on the glow plug can only be seeping down the valve stems and in through the port. The oil maybe buildig up overnight and then you gradually burn it off during warm up. Once you are hot and you have positve pressures in the ports - less oil will get through... So itis possible. Its difficult to say from the pic's - but as some remarked - could have a tinge of blue in it? How did your compressions look cold? Quote Link to comment Share on other sites More sharing options...
chrisbowler Posted May 28, 2011 Share Posted May 28, 2011 I think you will find that the glow plugs on 300 tdI are in a dedicated machined port that arrives in the combustion chamber about 25mm away from the valve seats - there is no way that oil from stem seals is going to migrate back up the glow plug hole - this oil is more likely to have come from the external and down the glow plug port and gathered around the thread. Also, how much oil is going to cause a miss fire when engine is cold but then not be apparrent when classic stem seal failure occurs on hot running on - say overrun down hills The more I read on this subject, I really do think that the problem lies with lack of compression on 1 cylinder when cold which improves as warm up occurs - cylinder head, piston rings etc Chrisbowler Quote Link to comment Share on other sites More sharing options...
Bullyjohn Posted May 30, 2011 Share Posted May 30, 2011 I agree Chris - the oil is more likely to have come down the glow thread itself. As you say it would also be likely you would see blue smoke on overrun and decels - not sure how easy it is to see this when you are driving - but easy to get someone the follow you and check... so the next thing to check is the cold compressions... has it done a lot of miles? Quote Link to comment Share on other sites More sharing options...
PaulN Posted May 30, 2011 Author Share Posted May 30, 2011 I agree Chris - the oil is more likely to have come down the glow thread itself. As you say it would also be likely you would see blue smoke on overrun and decels - not sure how easy it is to see this when you are driving - but easy to get someone the follow you and check... so the next thing to check is the cold compressions... has it done a lot of miles? Hi - not been here - thanks for all inputs... Cold compressions test yet to do when both parties can fit in. Truck has done 85K - a baby - just got back from Sis's place and we got 30.5 mpg! But yes there is a tinge of blue at certain times during billowing white cold start but in my opinion nothing to worry about and remember no smoke at all when warm (Blue, black or white!) Oil on Glow plug is not on thread. It's on the other end just up from glow tip from within chamber(See photo). If oil is from external via glow plug that would compromise compression when cold? This has a new rocker cover gasket and the glow plug tops were dry, stem was dry, just this band of oil at tip end. What you see in photo is as it was taken out of cylinder - other glows did not have oil - thought that might be relevant. No worries - will report when further tests are done. Quote Link to comment Share on other sites More sharing options...
chrisbowler Posted May 30, 2011 Share Posted May 30, 2011 When the glow plug is screwed into the head, the seal for the combustion chamber is the joint between the stainless steel tube and the point at which the heating element becomes less in diameter - this oil is therefore outside the combustion chamber. There is no other mechanism for sealing the glow plug and the head other than that rim pressing into the head. Chris Bowler Quote Link to comment Share on other sites More sharing options...
PaulN Posted June 1, 2011 Author Share Posted June 1, 2011 Three or four guys have independently suggested that they would put their shirt on air getting in the fuel system for one cause or another and then the fact that it not being compressable at first by pump. So we'll set up a temporary alternate supply of fuel directly to IP from a header, run truck and leave over night. If that's fruitless then a cold compression test. Both of these tests in 2 w/e's time when both garage, me and car are all available! Truck needs to be cold for both tests for proper process of elimination. For my part I hope it's air in fuel otherwise it's head off next and all that might reveal!! Quote Link to comment Share on other sites More sharing options...
PaulN Posted June 18, 2011 Author Share Posted June 18, 2011 Right - all important motoring out of the way so cold compression tests and then if necessary isolated fuel supply tests and then head off if necessary next Friday /Weekend. Just one thing before we do..... If a header tank of some sort is on top of the truck and then rigged up with an in-line filter directly to the IP - will that give sufficient pressure / flow to satisfy the demands of the IP for a 10 minute run? (ie) keep up as if with a Lift Pump? Or will we have to park up under a 200 ft chimney and sit reservoir on top? Who's run theirs for 10 mins? Quote Link to comment Share on other sites More sharing options...
edwardbahaw Posted June 22, 2011 Share Posted June 22, 2011 Looking forward to your findings! Quote Link to comment Share on other sites More sharing options...
Boydie Posted June 22, 2011 Share Posted June 22, 2011 I've had a similar experience, as in white smoke and only on start-up. it turned out to be a small coolant leak into number 3 cylinder, the only way I found out was the small (but constant) coolant loss, around 1/4 litre per 1000 kilometers Quote Link to comment Share on other sites More sharing options...
PaulN Posted June 22, 2011 Author Share Posted June 22, 2011 Truck going to garage tomorrow with list of to do's as above - I hope we fix it soon it's an amazingly good vehicle otherwise. Will take a day or two. Most would live with it and maybe leave it idling in the morning so it doesn't smoke! Sounds like you may have a smokey too Ed? Anyone got an answer for the delivery rate of the lift pump as compared to a Jerry on the roof? Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 22, 2011 Share Posted June 22, 2011 The lift pump only gets the fuel to the injector pump, which then pressurises it further, so gravity feed from a container will be fine and make no difference to your test. Les. Quote Link to comment Share on other sites More sharing options...
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