Austin 7

Hi Satnav systems work out their position using a number of orbiting satellites. The fewer the satellites they can receive, and the weaker their signals, the more error there is in the calculated position. The software takes the position and then "assumes" that you are on the nearest road (as long as there is one closer than say 50 metres), so snaps the "car" symbol onto the road. Most of the time this works so well that you are unaware of it. However, anything that significantly reduces the number of satellites that can be "seen" can give noticable problems, especially at complex junctions or where two roads run in parallel. Driving in a steeply banked cutting will hide satellites low in the sky. Driving under heavy tree cover (especially with wet leaves) will weaken signals. And of course, a faulty GPS antenna or a fault with its cabling or power supply can cause problems. Past posters have reported problems with the roof mounted combined GPS/Radio antenna due to water ingress. Alternatively there could be a hardware or software problem with the head unit.

Hi With some diesels, the low pressure pump in the tank (lift pump) runs when you turn the key to the first position, but is inhibited from running whilst you are cranking. Once cranking is over it runs again. If the rail fuel pressure (generated by the mechanical high pressure pump) is below a critical threshold, the ECU will stop the engine and store a fault code. Just wondering if the rail pressure is almost but not quite high enough at a critical point a second or so after the engine has fired up. First moves would be to get fault codes read and change the fuel filter in case it is restricting flow. Plenty of other possibilities of course.

Hi If you had an open circuit injector, the car would have been running on 3 cylinders and you would expect the performance to be terrible. Replacing with a working injector should give a huge improvement. Instead, things seem to be the other way round, which is hard to understand. I wonder if there is a problem with the injector connections and wiring harness, or the supply/earths to the ECU ? Injectors take rather large pulses of current, and will expose any weakness in this area. Also worth double checking that the cam belt isn't one tooth out - I once had that after a garage replaced the belt on a petrol Polo. We drove it like that for 5 years not realising why the performance was like a limp rag, until I got the job done properly.

Hi A failed release bearing tends to make a hissing/scraping noise as soon as it touches the diaphragm spring fingers, i.e. as the clutch is depressed. A failed DMF tends to make a rattling noise as the drive is taken up, i.e. as the clutch is released. On balance, I would say the noise is more likely to be the DMF. As you no doubt already know, given the labour cost of gearbox removal and replacement, it's usual to routinely replace the clutch pressure plate, friction plate and release bearing once it's apart. Unless the DMF can be proved innocent, I would be inclined to replace that too.

Hi My petrol 1.4 TSi is officially rated at 41.5 MPG, which I have no trouble meeting or exceeding. Even 50 MPG is possible under very favourable circumstances. And yes, this is checked at the pump as well as the dashboard display (they happen to agree). Your diesel 1.6 greenline is rated at 63 MPG, so if you are getting only low 40's it suggests something isn't right unless you are doing very short runs in the depths of winter. Does the car roll freely in neutral, i.e. no brake binding ? Is the engine getting properly hot, i.e. no fault with the thermostat ? Weight and rolling resistance are the main factors affecting economy below roughly 40 MPH, whereas wind resistance dominates above roughly 50 MPH.

Hi Charlie It the repairer's job to put your car back to the state it was before the accident, and the insurer's job to pay for it. You shouldn't have to run round spending time and effort doing their job for them. Why can't they go to a Skoda dealer, find the part number and order it ? Sounds like laziness/incompetence to me, and you would be justified in having a good old moan. It's certainly not for them to decide if something is needed - of course it is, it's part of the seal between engine bay and heater intake. And the bonnet fit, paint finish etc should be as per a new car. Too late now, but you can normally insist on your own choice of repairer, you don't have to accept the (cheapest) one initially suggested by the insurers.

Hi Before you get too carried away, it's always possible that this fault code is spurious and is also a result of a low/flat battery. I would be inclined to clear it, then check back from time to time to see if it reappears.

Hi Stubod I had this effect sometimes on the clutch of a 10 year old Audi A3 some years ago. As said above, there is an "over centre" spring as part of the pedal mechanism - a bit like a giant version of the ones used in household light switch dollies. This goes from opposing downward movement when the pedal is high, through a neutral position when the pedal is part way down and then progressively assists downward movement when the pedal is more fully down. I think the idea is that it gives a lighter clutch action. Around the mid position, the slightest change in friction can make the difference between the pedal returning or not, so lubrication might just help at the moment. I found that temperature and the amount of recent clutch use also played a part, and after a long motorway run without changing gear things were worse. I got practiced al lifting it with my foot, but it was unnerving. Fortunately it was behaving itself the day I sold the car to buy a Yeti !

Hi Alan It's hard to tell from a photo, but the original nut might be the type that relies on being slightly deformed to an oval shape ("stiff nut"), or it might be peened on with a punch. Neither of these is as good once movement has happened, either accidentally or deliberately I agree with Carlo diesel, and recommend replacing it with a nyloc type, making sure that the thread goes all the way through the nylon insert. A dab of paint or nail varnish will then act as a tell-tale for any unwanted loosening

Hi IDC The behaviour you describe is consistent with a thermostat that isn't completely closing. The temperature gauge has software between the sensor and the needle display, so that any temperature within say plus or minus 10 degrees of normal shows as a rock solid normal. That stops people worrying about minor fluctuations. If your gauge is showing anything other than normal once fully warmed up, then something isn't right. The only exception to this would be in extreme conditions, e.g. if you descended a very long hill in freezing weather with the heater on full blast. In that case you might find that because you were taking out more heat than the engine was producing (from engine braking only) the temperature would eventually start to drop.

Hi Yeti333 Glad you have sorted out the fan. The bearings are normally sintered and are porous enough to hold a little oil, but this doesn't last forever. I am curious about the dust and rust. Isn't the blower supposed to be downstream of a pollen filter that ought to stop all that ? Maybe the filter got flooded and soggy on some previous occasion ?

Hi Yeti333 It may be a coincidence that you have a faulty fan motor, as the code implies. If there is excess friction, they draw an abnormally high current which can be sensed by the control unit. When it gets too high it cries foul. These motors are normally accessible from under the dash without too much dismantling. The type I am familiar with have a bayonet style fitting, where you release a plastic tab, rotate the body 10 or 15 degrees (tap with hammer and wood) and then pull them out of their cylindrical housing. The motors will be cheaper from a factor than a main dealer, though I would recommend a known brand like Marelli or Delco. However its just possible that the two things are connected. Heater blowers take a fair bit of current (e.g. 30 Amps on full whack) and maybe the "system" has decided that it's best to temporarily disable it (not being a priority load) until the battery is deemed to have a better state of charge. But I have to say that a fault code would not be expected in these circumstances. I have had this disabling happen to the radio when listening to it when parked up. Alternatively, the climate control may have objected to a very low system voltage at some point, but I would expect it to be able to eventually recover without intervention. You could try toggling it between manual and auto and between different modes to encourage this. Don't take this as gospel, it's only an idea !

Hi again Some thoughts which might help. Water is electrically conductive, depending on what's dissolved in it. Rain water is near the least conductive end of the scale, muddy water in the middle and salty water near the most conductive. In the UK they pile salt onto roads in winter, but we fondly imagine that it never gets below freezing in Oz ! Also, the effect it has will depend on the resistance/current of the circuit it's bridging across. So a traditional low resistance/high current circuit like a metallic switch and a filament bulb will be fairly immune, whereas a high resistance circuit like a logic line or bus circuit is more likely to suffer. From your description, it sounds like the brake switch is tucked up away from any road spray coming upwards. So it's a puzzle that the switch and its circuit seems to be affected by wet weather. Probably worth checking that water isn't coming down from above, either onto the switch or any part of its wiring. Sometimes wiring looms have multi plug/socket connections near where they go through the bulkhead, presumably to make things easier on the production line. Such multi plugs can trap water if it drips on them or runs down over them when it shouldn't My final thought is on a different tack, but stranger things have happened. I wonder whether the brake switch lines run in the same loom as wiring to the wipers (front or rear), and chafing has occurred which is causing these two circuits to be bridged together. As soon as the wipers are used, the brake circuit will be upset. Alternatively, if they share a common fuse and there is a poor connection, interaction may occur. Good luck with your quest.

Hi I didn't appreciate that it's a Hall effect sensor, i.e. it responds to a magnetic field. Presumably there is a magnet forming part of the moving internal part of the master cylinder, and the magnetic field extends out through the non-magnetic metal wall of the cylinder. A Hall effect sensor is essentially solid state, so will require a DC supply and may have its own onboard signal processing chip, i.e. it's not just a simple metallic contact switch.

Hi Going back to Wino's post, this suggests that some models of Yeti are fitted with a brake switch actuated by hydraulic pressure rather than the mechanical movement of the pedal. Both methods have been used for many years. The switch in the drawing appears to fit into the side of the master cylinder and should be easy to spot. Gremlins after wet weather suggests a problem with something electrical which is exposed to damp, which is far more likely to be something under the bonnet (hood) rather than something inside the sheltered area of the cabin. It wouldn't be unreasonable for the brake switch signal to be used for purposes additional to the brake lights, so you might get odd effects if it is sensed that the brakes are apparently on when the car is being driven normally i.e. throttle not closed. I can only suggest a thorough check of the wiring and connectors under the bonnet, with connectors removed in turn and the pins inspected for any tarnish or corrosion.

Hi I had my doors resprayed by a body shop, after developing zinc inclusion "pimples". As far as I know, they removed the strips with gentle heat to soften the adhesive. The fishing line idea sounds good (same as used for rear badges) The bodyshop insisted that the old strips were not re-usable, and new strips were needed. These came with new adhesive on them. I don't think they were outrageously expensive.

Hi I agree with TruckbusUK. You have had the car 9 years without a leak, then you have had a new windscreen, and almost straight away you have a leak Even a tiny gap/hole will allow water to work its way in

Hi Rear disc removal requires a very tight (and awkward to access) fastener to be removed, which requires a 12 point tool. You might like to check with any proposed garage that they have done this job on a Yeti before, or the similar setup on a Golf etc. The caliper pistons must be wound back with the correct tool, due to the presence of the handbrake self-adjusting mechanism.

Hi Ben As far as I know, Skoda switched the 1.2 engine design to use a belt in about 2015. It's common to recommend replacement on both a time and mileage basis, whichever comes first. It's likely that the Skoda recommended time interval is 5 years. It's down to statistical risk really, if you go beyond 5 years the risk of a very expensive failure will steadily rise.

Hi James If you had a new 75 Ampere-Hour capacity battery that had somehow got completely discharged, it would need to be charged at 1.5 amps for ( crudely speaking) 50 hours to charge it back up. If the charge current is tailing off after only 10 minutes it suggests the battery is on its way out, assuming that all the connections are in good shape. You could borrow and try a beefier charger - 1.5 amps is rather low and probably more suited for a bit of topping up rather than a full charge of a high capacity battery. If you get hold of a DC voltmeter and connect it across the battery teminals, you should see something like 12.5 volts in the resting condition. If you then ask it to supply some load by turning on headlights, max heater fan etc it shouldn't drop below 12.0. A garage or battery service station would be able to do a more comprehensive health test.

Hi Kitchens Editing your RAC diagnosis and removing duplicates etc leaves the following fault codes: 18255,Fault codes in ABS controller U112300,Failure of the frame CAN bus 03839,Rpm sensor, left front; signal fault 00283,Front left wheel speed sensor 00668,+30 voltage 01325,Tyre pressure monitoring Multiple warnings/fault codes are often due to the common cause of a failing battery, but you have checked that. I assume the 12.8 V was off load, one would expect nearer 13.5 to 14.0 V when being charged. Previous forum posts also suggest that the loss of an ABS sensor signal can upset multiple systems. However, it's interesting that you are getting DTC 00668, which suggests that the +12V supply to the ABS unit may have a problem. The code 30 means it is derived directly from the battery, i.e. not via the ignition switch. Even if the battery is OK, there could be a poor connection / loose fuse etc in the supply to the ABS unit, causing a more localised loss of voltage. This may be exacerbated when the ABS unit is actively reducing the brake line pressure, when its current consumption rises as its internal solenoids come into play. More current will of course cause more voltage drop in any poor connection. I suggest you check any fuses and cables in the supply line from the battery to the ABS, to eliminate the possibility of trouble here. However, be aware that DTC 00668 can also be logged in cold weather if the (possibly slightly tired) battery voltage dips too low when cranking

Hi Those ECU casings normally have a good elastomer seal. However, the mating multi-pin connectors on the loom may not be quite as well sealed. No harm in easing one off if it's accessible, and inspecting the state of the pins. Take care putting it back that none of the pins get bent.

I've just come back to this thread, hadn't realised that I put the cat amongst the pigeons by referring to the previous threads on battery coding. The way I read it, the VAG "Closed System" is nothing to do with closed or open loop control systems, but is closed in the sense of a closed market. The cynic in me would suspect that this is partly about keeping the replacement battery market to themselves, and I find it hard to swallow the vague warning about increased battery wear. The battery management system is capable of continuously monitoring battery voltage and the current flow in and out, so is quite capable of determining the health of the battery. I see no reason why it cannot recognise a new (or healthy) battery (of the correct type and capacity) being fitted, and re- adapt to it within a space of time. That's what I meant by "robustly designed". After all, the other systems in the car can recover from an inadvertently flattened battery after a short time of running, though you might have to re-enter stored radio stations and phone numbers etc. I'm sure if you are the driver of a new-ish car and pay for main dealer servicing you would be a bit miffed if you went in for a battery change and then drove home still seeing warning lights/messages, so coding is great for such customers. everything works straight away and there is a log of a new battery being fitted. On the other hand, if your car was a few years old and you broke down on a wet and windy night and the local garage fitted a new battery without coding, you would be equally miffed if the car wouldn't start or displayed error messages for ever more. I appreciate that this is all surmise, as I don't have details of the software used for battery management, I suspect that's a closed shop too. At the end of the day, it's the original poster's car and up to them to do as they choose.

Hi Cornish Lad It seems to me that there are three possibilities: The car isn't charging the battery correctly You are doing only short journeys and the drain is exceeding the amount of charge being put in Your battery is on its way out, especially if it's more than 5 years old The terminal voltage of a battery gives only a crude idea of its health. As a battery ages, it's capacity diminishes and its internal resistance increases. You can end up with the electrical equivalent of a teeny motorbike size 12 volt battery sitting inside your big car battery casing. OK, it will still charge up to a normal fully-charged voltage, but give it any serious work to do and the voltage under load will melt away. This often first becomes apparent when the weather turns cold. I can't help feeling that it's new battery time. At least you have time to shop around for a good price, and changing it yourself isn't too difficult. If you look at previous threads you will see that in theory the car has to be reprogrammed after a battery change. I suspect this is a "nice to have" rather than a "must do". If it's robustly designed, the smart charging system should be able to sort itself out given a little time.

Hi Muttontop "I’ve read on this forum that there are 2 antennae’s for the DAB with one situated in the rear screen heater element" As far as I know, the two antenna (diversity) setup is only applicable to FM. The technical characteristics of DAB make it resistant to the effects of multipath reception (lots of reflected radio signals in the reception area) so only one antenna is necessary. I don't have any technical detail on the Yeti DAB antenna, but imagine it is incorporated in the roof-mount unit, different parts of which serve AM, FM, DAB and sometimes GPS. It will have a dedicated DAB coaxial cable between head unit and antenna, and there may be a pre-amplifier in the antenna base which will need a 12 volt feed at fairly low current. Again, this feed may share the antenna cable or be supplied separately. If it comes down the antenna cable, it may be necessary for the head unit to be programmed to provide it, but I would expect this to be the factory default setting anyway and it won't come and go. If the DAB antenna is faulty/disconnected, or if any associated pre-amplifier is not powered, you are unlikely to get any signal strength indication or any reception at all. There have been past discussions on this forum on the roof mount antenna and its cabling. If water gets in, parts may fail but this may only affect some bands. DAB reception can be a little patchy, and the fallback to FM is supposed to tide you through a small blackspot before reverting to DAB. It sounds as though the head unit is managing to switch to FM, but is failing switch back again for some reason.