NeilTM

Fabia 1.2 petrol 55 plate. BME engine. Firstly, a fond hello to Wino if he is still here, and who saved our daughter's Fabio from a fruitlessly expensive journey to the scrap yard for the mother of all obscure faults - a still mysterious break in the wiring in an inaccessible part of the cabin behind the dash next to the bulkhead, in a cableform - an absolutely brilliant piece of patient sleuthing and testing by Wino that undoubtedly avoided the inevitable ECU change the professionals we contacted would have needlessly inflicted on us to no purpose. 2.5 years of fault free motoring later, we arrive at another challenge to its future after having just had two broken springs replaced for the MOT, all too quickly followed by replacing a clutch as well for a broken release bearing, which we also correctly diagnosed. In a nutshell, the subject line is what we need answers to to be confident that the Mr Clutch franchise we employed to change the clutch were in fact responsible for failing to prevent a known hazard, namely the timing chain being caused to jump a couple of teeth, which we believe to be the case from our own investigations. A preliminary phone call to the garage met with denial of failure to secure the flywheel from moving backwards as it would upon tightening the clutch cover bolts if not first secured. This according to more than one forum post we found can cause the tensioner to 'unload' its tension, precipitating a jump of the timing chain of one or two teeth. Further confirmations that this is known to happen would be appreciated. No engine management light was on when the car went in for the clutch work, nor when it left for the 2 mile journey home, despite this being contradicted by the person we spoke to who said that he had done the work, and who claimed the light was on when we brought the car in, yet never informed us of this at any point. So my first Q is how long is it likely before the ECU would recognise the persistence of a fault, as opposed to a transient, before logging trouble codes and putting on the engine management light? The delay experienced was a 2 mile journey home, plus approx 1.5 miles into a trip the next day before it came on? Is this a possible delay? However the running and power was noticeably poor from picking up the car compared with how it was, taking it in. The garage obviously noticed something amiss because they reported that it had an engine fault, in that the revs were limited to 3,000 whereupon the engine cut out until the revs had dropped down a bit. They speculated it might be a blocked cat and we let them book it in to investigate the problem for this coming Thu. Meanwhile we put a basic code reader on it and got: The first scan was on "Engine" and the codes were: 16725 16490 16556 16514 The second scan was on "ABS" and the codes were: 01314 18265 I understand from others of Wino's and other posts and informations that the last two ABS codes merely point to going to look for engine management fault codes, is that correct? The best informations seemed to be at: https://mechanicalee.blogspot.com/2013/03/volkswagen-audi-skoda-vag-fau lt- codes-engine.html The last lines being a list of possible causes of the error codes. 16725 - Camshaft position (CMP) sensor A, bank 1 - range/performance problem Insecure sensor/rotor, air gap, wiring, CMP sensor 16490 - Manifold absolute pressure (MAP) sensor/barometric pressure (BARO) sensor - range/performance problem Intake/exhaust leak, wiring, MAP sensor, BARO sensor 16556 - System too rich, bank 1 EVAP canister purge valve, fuel pressure, injector(s), HO2S 16514 - Heated oxygen sensor (HO2S) 1, bank 1 - circuit malfunction Heating inoperative, poor connection, wiring, HO2S 4 fault codes and 3 sensors suddenly being implicated, having never been seen before, and the last time I checked for codes was this Sept before the MOT, only getting DTC: 01 00532 - battery voltage too high or too low, (I think in relation to airbag operation?), and not seen since. So when we stumbled upon more than one report of recent clutch changes as being implicated in throwing the timing out with at least two of those codes, 16725 and 16514, we checked this out: Using a mm graduated rod through the plug hole to determine TDC on No.1 cylinder, we observed the angle of the notches on the end of the crankshaft by removing the plastic end covers, and photographed the misalignment that was indeed present, according to forum information that at TDC the notches should align parrallel to the face of the cylinder head. Is that correct, and does anyone have an authoritative source for that information? I ask as I want to be certain of my facts before perhaps deciding I don't want to trust this garage to carry out the corrective work, if they, as it seems were unaware of having caused the fault, and thought it might be something expensive like the cat being blocked which I can't see implicated anywhere, and they seemed in denial and defensive over the fact of whether a prior engine management light was present, and of the possiblity of an unsecured flywheel turning backwards at some point. They also claimed there were no fault codes, but seemingly contradicted that by saying that they would look for historical fault codes as part of diagnosing the cause of the bad running and 3,000rpm rev limit, which would of course have showed up no less if they had checked the codes, and without checking the codes they cannot possibly know that there weren't any as they claimed! Nor can you have the engine management light on and no codes presumably? There is no date time stamp on these code occurances is there? Do they log mileages with the codes? If it is reasonably believed that the business in question cannot be trusted with the work or to take proper responsibility for their mistakes, I understand that we ought to be entitled to engage another business to do the necessary work and report honestly on what they had found. If that matches what we are saying is wrong, and what caused it, I would put in a claim for the cost of that work to the original garage, and be prepared to take out a county court summons to recover the amount, plus costs if they held out, and defend our claim in the court. Unless of course I am persuaded of not having such a case, hence my post. I want to get them to agree in principle to not making a charge if our analysis proves correct, and the whole story, otherwise given their response so far I don't feel confident of honest dealing, or competent work, and would at such a point of refusal tell them I was taking it to an independent garage instead and will charge them for the work unless their report was inconsistent with our analysis of course, but there is no way that this car went in running as badly as it came out, and with these fault codes, and observable bad angle of the cam shafts, so it seems reasonable to assume that it still wouldn't have these problems if they hadn't been precipitated by the garage. We have calculated an angle that we believe the timing to be out by based on the published length of the stroke (86.9mm) and the 11mm we measured the piston rose by before levelling off, after the notches had already aligned parrallel to the cylinder head: 22.78 degrees, which at 10 degrees per tooth (is that accurate?) would indicate at least a jump of two teeth. Have we got that right based on those figures? The actual angle from the photos looked possibly steeper than that, but some of that could be going past TDC, but before the noticeable fall of the piston. Measuring the rise after the point of camshaft notch level seemed a more reliable guide to the actual angle of error though. Finally is it possible for an engine to run driveably, and without damaging anything, albeit under 3,000rpm, which is quite restrictive on this engine, when the timing is out by this amount - about an eighth of the piston's travel to go to catch up with the cam shaft? Best wishes, NeilTM