Norman Willcox

So did an auto scan with Ross VCDS - no faults shown other that a permanent radio one and dodgy windscreen wiper steering-wheel switch. I don't know whether or how I can investigate further for problems of injector timing/faults with VCDS.

A garage mechanic has suggested that an injector has started to fail. Is that a possible cause?

OK I shall run VCDS tomorrow. No faults have appeared on the car screen. I suspect that VCDS may not show any either - but I shall see. When I turn the ignition switch, when hot, there is a very nasty banging vibration which gives the impression that the engine fired backwards, and then fails to start. It usually can be started the second time but that too is not as smooth as silk. Engine code is BJB. What torsion value should I expect?

I have no idea how to check the injection timing and I have no figures to judge whether it is correct or not. If I were able to establish that the timing was wrong - then what to do?

Ouch! JR You think that the DMF is about to fail again? It certainly must be being bothered with the horrible banging about. But that is not likely to be the cause of the pre-ignition - just a result?

I have Ross VCDS, but I have very limited ability with it. I have used it for diagnosis of airbag faults and sorted those, but I have never interfered with the software. Can the injection be delayed during hot starting? How to do that? I assume that the timing and the positioning of the toothed belt is correct since the engine performance seems fine. ( I have had a new second hand engine fitted after a failure of the DMF damaged both.

My 1.9 2006 Diesel Octavia 2 makes a terrible shuddering banging failure to start when the engine is hot; starts beautifully when cold. Any one know what can cause this? It is evidently pre-ignition, but why?

Hi Tilt, I am confused and disgusted too. Hasn't anybody any done any R&D on headlights? They are a scientific and engineering disgrace. I could do better with a candle and a decent parabolic reflector! What useless beams they produce! Yes, one of my adjusters is a bit stiff and the internal hex drive can slip, but then any decent mechanic could have used the external hex, which would have had more purchase. For the amateur, without any kit to offset the random beam-forming produced with these astonishingly expensive and poor performing reflectors, it is rather difficult to arrive at something that might match a CT (MoT) wizard operating his fancy gadget. I think I achieved a result approaching what is required, out in the bundu, with my black plastic masks and palette screen. Yes, I was surprised that the bulb-failure indicator lit; I stopped the car and walked round it, testing all the lights and noticed nothing wrong. I stopped the engine to allow it to reboot - no change. But I am pleased to report that this evening the indicator does not show. Bloody computers! I have not been interested in the Skoda today; the whole exercise is to make it saleable for another unsuspecting Brit who is desperate for a cheap car to replace his defunct Kia. I have been busy fitting a tow-bar to the UK-Reg Insignia stop-gap which is intended to get me back to UK ahead of Effing Brexit. Boy, was it sweaty! Not sure that I get your suggestion about resetting the adjuster push-rods; surely the only way you might run out of adjustment would be when the push-rod thread bottomed at the end of it's travel. If more was needed - tough! I think these stupid poncy headlights are both over-engineered and under engineered at the same time. What on earth is wrong with a nice circular sealed-beam unit, such as the Americans kept for ages after the European market chose to go arty? Well, global-energising is going to bring all of us to heel! Thanks for everyone's inputs, much appreciated.

Hi J.R. No that's fine. Slope changes angle continuously outside the garage. Just been out to try re-aligning the lights on a relatively flat section. Horribly difficult! I think they are better and driving with them is better than before, but whether they are in spec, I don't know. LH seems a bit odd in that there is some flare across the road to the left, though low down. The bulb failure indicator is now showing, even though no bulbs are apparently blown. I wonder If a lead has come adrift from the headlight connector? Is there a separate current sensor wire ? Don't think so! Time for bed.

My French is not good or quick enough to argue the toss with a southern-accented technician - sadly - or I should have been more insistent. My car is French, bought at Narbonne. The replacement headlight will have been bought by the repair garage using the Carte Grise. I still have the identical old one which is missing the fixing stud, broken off. Yes the levelling motors are working fine. The setting on the dash roller control is zero. Thank you J.R. all advice is welcome. Unfortunately my ground is not level, it falls away just outside the garage. I have a wooden palette which will stand on end, so I shall take that with me to the back lane behind the house and mark it as you suggest. Am I right in thinking that there are only 3 adjusters V&H for dipped and only V for main beam? So the dipped beam is independent of the main beam? It was quite a fiddly job getting the headlamp to reseat properly and the hockey-stick slider does not seem to anchor the headlamp absolutely securely - maybe there was some panel damage from the accident which was not corrected and that is maybe responsible for the changing beams. (Except that that would not explain significant vertical alignment, which has been the major fault.)

I removed the LH side head lamp. Turning the adjusters results in the reflector moving just as it should. There is no play of the reflector. Lamps are properly seated. I can see no reason for Norauto to report that the mechanism was "casse". And I still do not understand what has been giving me the change in alignment. I shall attempt an alignment on a back road tonight - pity it is not winter! Whether I can achieve a satisfactory setting for the next CT remains to be seen. In the pictures the flexible drives and the 3 sockets for the balls on the end of the push-rods can be seen.

Thank you Tilt and J.R. I have had a look this morning in my garage, pointing the car at the door, lined with polystyrene. The distance lamp to door is about a meter; I twiddled the adjusters and it seemed to me that the very hazy beam blobs were moving, both ways, up and down, making me doubt the garage. The electric beam levelling worked fine. History: years ago a young idiot hit me head-on, just failing to stop in a one-lane track. I had stopped and he needed another 1/2 meter. That hurt one headlight which was replaced, but the garage did not have the large white hexagon nut that holds the headlight (that was what was broken off on the original) - I did not notice for a long time. Before the last CT inspection I was aware that the beams were not well aligned so I took the car to "Point-S" who did an adjustment but the car still failed on beam alignment. Point-S was made to redo the adjustment and the car then passed. But after a few months I was aware that a beam had become seriously unaligned - don't know if it was one or both and I don't know why . Before this latest adjustment work I tried an 8mm nut on the plastic thread that protrudes from the headlight, but the thread is not 8mm, so I used 10mm nuts to fill the gap and forced the 8mm nut to cut its own thread. Maybe Norauto did not like the bodge. So it is possible that that one headlight was not being held properly because of the lack of the white hexagon nut - maybe that is what allowed the alignment to slip - though I think it unlikely that it could have made so much difference. I shall try after dark on a back road to see if I can improve the alignment. I am puzzled as to what is/has happened. I did have to change a dip-beam bulb last year. I think I had better remove that headlight so that I can look inside it and check that the bulbs are correctly held. I have always wondered how those beam-alignment gadgets cope with the scattered blobby light from the headlights, which never seem to produce distinctive patterns.

Thank you J.R. That is a kind offer. I don't know yet if it is possible to change the adjusters inside the headlight body. Our Octavia is French. Once I have investigated, I may wish to get back to you. Please would you send me an email so that I can get in touch again? My email is [email protected]. We are tending to use Le Havre Portsmouth or Cherbourg Poole for our crossings, but our next trip cannot be soon as SWMBO has broken her fibula and I am to have a replacement hip in a couple of weeks. I have time, CT is next June and I don't drive at night, unless forced. Best wishes, Norman

2006 Octavia 2. I took my car for headlight beam adjustment, because the beams were obviously wrong, and was told that the adjustment mechanism on both headlights was broken and so they could not be adjusted. Unfortunately I could not speak to the mechanic so I got no details. I am in France and currently the temperature is above 41 degrees C, so I am not prepared to work on the car, even in the garage! Last year I had the beams adjusted by Point-S and the car still failed its CT (MoT in UK); I made Point-S redo the adjustment and the car passed - but now I suspect it was Point-S who wrecked my lights - can't prove it a year later though. New lights are over 100€. Has anyone any bodge repairs for broken adjusters?

Yes, you are right; I did say I know nothing about these engines. The tube comes from the fuel filter and disappears towards the pump-thingy. Back to the drawing board. And no, I think I shall leave it alone.

Found it at last - it might have bitten me! But it is nothing like the bit in the diagram. Trouble is, if I release that green clip and pull the sensor out I shall have coolant peeing out. It is not obvious if there is a connector, or if there is how to release it. (There must be!) I sussed how to release the other connectors last week but this one looks different. When the engine is cooler I shall try squeezing that lever with a pair of pliers.

Hello Wino, thank you for the two posts. I don't argue with your logic. It is a fact that the ECU can establish the condition of the glowplugs when they are not fired up, so something recognises that the high impedance 6 volts has been shorted by the plugs. The FETs carry the high current when so commanded but it is doubtful that they also provide the supply for the checking function so something else is probably connected to the FET outputs. Are we sure that the 6 volts is produced within your plug control unit - is the supply definitely 12 volts from the battery/ign. My engine is a BJB. The diagram you found is for BKC, BXE. I can't see that Tee piece attached to the short cylinder at that end of my engine. I don't know much about these diesel engines; it looks as though there may be an injection pump (?) located where that temperature sensor is. There is a castellated short cylinder under this pump with a bunch of leads coming out but it is nothing like your diagram and it is not obvious how the leads might be disconnected - doesn't appear to be a connector there. See pics Thanks also Superb. Yes it may be too much trouble and the car is away with the better half just now. I don't suppose VCDS could turn off the sensor, could it?

Nope. No help at all Superb. What the L is a tandem pump? Don't bother answering that query - just send a picture. I did remove a couple of sensor plugs and got told off by the ECU and VCDS. There is a sensor above the radiator in a small tube, and that must be about temperature, but is it the right one? I have seen no green plastic clips and I can't imagine a "sort of plastic coolant flange". That sensor after the air filter box is a flow sensor isn't it? I have a suspicion, given the ever-so-smooth DC voltage seen on the scope, that there may be nothing to observe with the scope attached to the plug controller output leads. If we are interested in how the plugs are driven, under starting conditions and thereafter, it is probably current that we should be trying to measure; the resistance of the plugs will go up sharply as the element gets very hot and the voltage may probably be controlled lower - but that won't tell us much without knowing the instantaneous resistance. We already know that 6 volt heavy current can be produced by the controller and that the plug elements will care little whether it is smooth or pulsed. We are unlikely to be able to fathom much about the designers intentions of intensity and timing from voltage measurements, though a scope or multimeter could tell us that the plugs are being fed. a+ N

Hi Wino, I too am clueless as to what is going on. Since I was able to clear the faults shown up by VCDS it must be so that the ECU is content with its sensor input. I do not know if the glowplug connector has 2 wires inside it. There might be a monitor connection - or not. But somehow the ECU learns that there is a satisfactory low resistance at the plug. I had hoped to detect a mark/space ratio of half; the fact that I did not disproves nothing; it may well be that the output is sufficiently smoothed and actively controlled to be so. Since I did see the 1.4 Volts with ign off, I suppose it is possible that it is this value that the ECU considers to establish the plug condition, but equally it could be the 6 volts presence/absence when the ignition is on (More likely perhaps). The ECU has the opportunity all the time to assess the plug condition because most of the time the plug is not needed to glow. When it is required to glow by low temperature, the ECU does not need to assess, merely to drive the plug.

I am very bad at getting rid of tools and equipment despite the rarity of their use; my scope has also laid idle for a very long time. Electronics, much like auto-engineering has advanced and changed so much that the retired professional/amateur is somewhat kept out of the business, and that is also why the scope does not get called for much. Regrets aside, you were probably wise to sell your scope.

The Bosch glow plugs arrived from Oscaro on Wednesday. I pulled all the connectors off the old plugs and fitted a new plug to No1, in mid air, with a thin wire around the glowplug terminal and down the connector. I attached the oscilloscope probe to the wire and used a croc lead to connect the glowplug body to the negative battery terminal. Disappointing result! With the ignition on or off, the scope showed absolutely no voltage, and the plug did not glow. A multimeter in No2 connector showed the usual 1.4 volts with ign off and 6 volts with ign on. So the 6 volts comes through a high impedance and is shorted to earth by the glowplug. This is probably because the ambient temperature was 15.7 degrees C and the ECU knew that no glow was required. I connected the scope to No2 connector with Ign on, and with the scope on AC, the waveform shown appeared (No plug connected). The amplitude of the pulse is about -0.1V and the intervals are about 0.6, 1.2 and 2.6mS. (1mS/cm) Not very high frequency. The scope would not sync very well because the waveform was not stable. With the scope on DC, the 6 volts appeared flat - no pulse, no apparent ripple. I removed the old plugs with no difficulty and fitted the new ones with copperslip. VCDS showed no engine faults after clearing the old faults. Job done. I know a little more.

Well done Wino. Evidently the ECU will tell this controller what to do and when, having gathered temperature data etc. I intend doing some measurements when the new plugs arrive; I shall pass on anything that I find.

I mentioned the discussion about the Glowplug controller to my electroniky younger son and he has given me a link that goes into the techniques at some length. You can skip the maths and glean interesting information. Son says that the controller will be a "buck" or "buck-boost" circuit. See https://en.m.wikipedia.org/wiki/Buck_converter if you have the time! These techniques are used commonly in computers and mobile phones and more ore less everything else!

J.R. I am not sure if this is relevant for you. My Octavia did not come with a tow bar etc.. I fitted my own and bought a relay thingy from Ebay. It does not upset the Canbus and used to bleep correctly with the indicators until I changed the trailer board to LED lights. Now it bleeps intermittently and stops when the brake lights illuminate. I needed to have a battery connection in the boot so I fitted an in-line fuse and attached it to one of the spare live terminals hidden under the battery fuse box lid, at the front. You can see this in the photo I attached many posts ago. (The picture is at the bottom of the 1st page above). You can see the fuse connected to the 5th stud from the left.

Would a digital multimeter show 6V for a 12V even spaced PWM supply? And no I am not going to attach the oscilloscope just now, but I might when the plugs arrive.