Breezy_Pete

Instructions for checking internal hose below. Passenger side. (LHD shown, I expect, though diagram makes little sense to me as a non-owner). Mirror everything.

Expansion tank level looking unchanged, and a moderate 'pschutt' of pressure release when opened this morning. Chain elongation fault code had returned since last cleared. 1 Fault Found: 18723 - Chain Elongation P150D 00 [01101101] - - Confirmed - Tested Since Memory Clear Freeze Frame: Fault Priority: 2 Fault Frequency: 1 Mileage: 266043 km Date: 2029.14.24 Time: 12:08:37 Engine speed: 2531.00 /min Normed load value: 28.6 % Vehicle speed: 103 km/h Coolant temperature: 92 C Intake air temperature: 20 C Ambient air pressure: 1010 mbar Voltage terminal 30: 13.913 V Unlearning counter according OBD: 40 Timing deviation after chain replacement: intake bank 1: 1.56 Timing deviation after other repairs: intake bank 1: 0.00 Timing deviation: current value intake bank 1: 5.93 Chain elongation: no. of valid initial values: intake bank 1: 5 Readiness: 0000 0100 Think I might acquire a spare engine and work on it to be ready for a quickish transplant if required. If only I had plenty of space. ☹️ I have acquired the chain repair kit 03F198158B at what seems like a bargain price of <£120 from a local dealership. Includes chain, cam and crank sprockets, guide rails, tensioner and all screws and bolts; but now unsure if it would be a poor investment of time and effort to use this on the current engine. Anyone know what, if anything is different in the complete CBZB engine for an automatic versus a manual transmission car? My favourite, low-mileage complete one currently on ebay is from an auto. Edit: researching the above question, flywheel is different, but tends to be un-included in spare engines I've seen. Then some bits of the breather system seem different, but not a lot else.

I think only one of these will fit, it needs to match the manufacturer of the original system. Even if you look up with VIN filtering in a genuine parts catalogue like partslink24, you get a comment "Before parts order, physical inspection of old part necessary". If you would like me to try to look up the part number in case it is possible, tell me the VIN. I think you can establish if the system you have is Denso or Valeo by looking at the label on the blower motor, if there are no more accessible labels than that one. The substance in the header tank of "mit silikat'-marked tanks is silicates, not silica, and the function is to replenish levels of these chemicals that are present in the coolant when made, but get depleted during use in the engine, by chemical reactions. Not to absorb moisture, which is plentiful and desirable in coolant.

Thanks for the interest. Yes and no. Seems not to be as worrying as first feared, but I don't yet understand why. Main driver took it on a reasonably long trip (3hrs each way) this week, and checking of level in expansion tank prior to return journey suggested no loss of coolant or pressure-related change in level. Will have time at the weekend to look at current level and to open cap and listen for any unexpected pressure. Have temporarily stopped actively looking for the right spare engine on ebay. 😀

MOT manual is publicly available here: https://www.gov.uk/guidance/mot-inspection-manual-for-private-passenger-and-light-commercial-vehicles If anyone can find a clause anywhere in that which says "any warning light is a reason for failure", please share it. A lot of nonsense gets repeated online about such things, along with the old chestnut "if it's fitted it must work". This is also not true. If that manual doesn't mention something specifically, then that thing is not part of the test, and therefore cannot be a reason for failure. If you look at MOT fails, they are always listed against the specific (sub)clause in that test manual linked.

Oh that's ideal (especially if it was me, as they're just down the road). That's just a Skoda dealership with an online parts selling operation. Have used them once or twice, no problems.

This lot may have stock of new genuine, at quite a price. Check availability with them: Volkswagen / Skoda Vacuum Pipe With Non-Return Valve 6Q2612041AK - LLLParts

Yeah, that's properly broken. Is there enough length to trim away that end and reconnect further back? (would need careful heating of plastic).

I'll aim to get some info up this evening or at the weekend. Circuit is rather simple within the BCM, at least with regard to the power outputs to wiper motor. Input from permanent 12V fuse in on one pin, a relay switches this when wiping is requested through to another relay. The second relay switches between normal and high speed wiping, each having its own pin and wire to the wiper motor. The first relay, if contacts stick/weld closed, will result in wipers going continuously until fuse is removed. Main difference from earlier BCM versions is that these two relays are separate tiny ones here, versus a single, slightly larger, dual relay in previous versions.

@AlaricT did you get this solved? I have now identified the relay that I believe must be responsible in this version of BCM, and have some on order which should be with me very soon.

Normal. The servo has to let cabin air into its rear chamber when pedal is pressed, to provide the assistance. I suspect your attention to it has just been heightened by anxiety about brake function.

Maybe every 100k. Or with a clutch change whenever that may be needed.

No, not at that mileage. Complete waste of time and money (and oil).

Brim = 1st click on nozzle.

Yep. Brim to brim with zeroing of trip meter each time can't help giving the best accuracy that's easily obtainable.

I can look up part number via the VIN, I'll start a private chat with you in a sec. Unless there's worse cracking on the far side of any of those points, I would probably recommend a repair with self-amalgamating tape. Especially if a new replacement does turn out to be unobtainable as suspected. If it wasn't actually icy at the location of the incident, it may have been surface contamination by diesel fuel, or oil of some kind, leading to one or more wheels locking up unexpectedly and triggering the ABS.

That was just the ABS kicking in I think. Did it feel like the pedal was vibrating harshly underfoot? As with any VW group car of this era; probably a good idea to check the brake servo vacuum hose for cracks at the junctions of the hard plastic sections. Edit: and check your tyre pressures, MOT doesn't.

Thanks Lee. Currently trying to dream up an explanation that isn't head gasket.

Found that the oil level was rather low, despite no external leaks these days. Must be burning some. ☹️ Has done a fair number of miles since I last looked, so not too alarmed. Buuut, just this afternoon, went to re-check the oil level (fine) but noticed coolant was a bit low. Hadn't been driven for almost 24 hours when I opened the expansion cap to top it up. Sickening sound of pressure release, stone (ice!) cold engine. Oh dear...

And you'll get exactly the same divided opinion here. I'm in the 'car will figure it out just fine' camp. No-one ever really produces any proper evidence either way.

Try here: https://www.lllparts.co.uk/catalogs

It is probably part of the procedure for removing the light switch. Certainly is on earlier models; push and twist, can't remember which direction.

What makes you think it needs a cambelt change?

Logic suggests that a correlation error is not a fault with either sensor (which would have dedicated and specific fault codes) but a strong hint that the belt has not been fitted correctly, and the engine is mis-timed. Maybe the garage has used incorrect locking tools?

I can't see anything in the wiring diagrams for a BMN that calls itself "Sensor reference voltage A" unfortunately. There are various 5V outputs from engine ECU to various individual sensors, and one that goes to two via a splice in the loom, G581 Position sensor for charge air pressure actuator and G212, the potentiometer of the EGR valve, both coming from pin 26 of the ECU, white/yellow wires to both sensors. No idea if this is the specific supply that the fault code is referring to, or whether it is all of the 5V power outputs from ECU. Not much help, sorry.