Austin 7

Hi You might think that the spec. would vary between the lightweight humble 1.2 Tsi and the full blown 2.0 170 hp 4x4, but according to the fitment list the same unit is fitted throughout.

Hi You say "there are 2 next to each other on the top of the engine with one hose going into each. It was like £70odd +vat". As the DPF sits in the exhaust pipe and costs more like £750 it clearly wasn't that. Was it the DPF differential pressure sensor that you changed ??

Hi In response to J.R., I must admit that damage from resistance checks with a modern digital ohmmeter did seem rather unlikeley. Maybe they were thinking of an old analogue Avometer with a 15 volt battery or even a megger. I guess sooner or later someone will try using one ! The reading of hundreds of kilohms puzzled me at first, as it seems much too high for something intended for the automotive world where the leakage from a bit of dirt and damp would be of the same order. An earlier type inductive sensor would be nearer 1 kilohm. Having read up a bit, it would seem that Magnetoresistive sensors are rather ingeneous, as despite containing an electronic circuit they are able to share their output signal with either the supply or ground wire, so only need two connecting wires. Normal current through them when working alternates in pulses between 7 and 14 mA, and a sense resistor in the (external) control unit of for example 100 ohms turns this into a 700 mV peak-to-peak voltage signal for conversion by an ADC. Normal voltage drop across the device is about 10 volts. The test voltage of a digital ohmmeter is typically between 1 and 3 volts, which is probably not high enough to make the internal electronics "come alive" even if it had the correct polarity. The resistance reading is therefore not very meaningful and may vary from meter to meter if they use different test voltages. However, it's useful in so much that it indicates that there is some internal connection.

Hi I don't know what type of sensor is in the Yeti, but if you have a Magnetoresistive type, PicoAuto advise against resistance testing due to a risk of damage: https://www.picoauto.com/library/automotive-guided-tests/mre-wheel-speed-sensor/ A voltage test with a scope on the combined power feed / signal output pin should show a signal of typically 11.0 to 11.25 volts relative to ground as the wheel is rotated, i.e. quite a small swing. Anyone know what sensor type is fitted ?

Hi Doesn't the Silentbloc refer to the 4WD propshaft coupling/damper ?

Hi brummie10 I would find it surprising if two injectors just "went", I suspect it's more likely that they have progressively worsened over the years, and were possibly faulty to some extent from new. The ECU knows fuel pressure and the time duration for which to open the injector to supply the desired amount of fuel. This is all fine if the injector is working properly, but if it isn't there's no individual (i.e. cylinder by cylinder) feedback to tell it that anything's wrong. If they were injecting more than they were supposed to, you would get poor MPG and uneven power delivery from the 4 cylinders. It's also possible that soot emission levels would be raised, which may have hastened the demise of the EGR valve by choking it with deposits. I share your frustration at the costs, inflated by the workshop time taken to cope with poor accessibility. The EGR probably costs £50 to make and £100 to buy trade. Then changing it requires dismantling half the exhaust sytem. The EGR may have reduced the NOx emissions (a bit) but think of the waste caused by having to make a new one, scrap the old one, change the oil etc etc. One wonders whether this emission reduction stuff is a bit of a theoretical exercise to satisfy the powers that be, with no account taken of the whole long term picture. Anyway, rant over ! As for asking for compensation, I suspect you would get nowhere with a 5 year old car, never mind a 10 year old one. Save yourself the angst and just enjoy your better running car.

Hi If it's high frequency noise I'd be looking for poor sealing of doors/windows as suggested above, or even the bonnet seals. If it's more a low frequency boomy type sound it might be worth checking the various exhaust mounting rubbers in case they have gone missing or gone hard with age. Any part of the exhaust touching the body work ? Any exhaust leaks, including the flexible section near the engine ? Engine mounts OK and no part of the engine/gearbox touching anything that it shouldn't ? The only other things I can think of is that the engine is working harder than usual (but you would see that in poor MPG / brakes binding and getting hot etc.) or the French authorities have spent millions giving you super smooth roads to reduce tyre roar so that you can hear the engine better !

Hi I am going to throw in an odbball suggestion for elimination purposes. I once had an odd tapping noise from under the car (1.4 TSi 2012) on the passenger side, audible at idle. It turned out to be the fairly rigid plastic fuel lines (flow and return) between engine and rear tank. For the front part of their length they run inside a hollow rectangular box section. Although Skoda fitted foam inserts in the factory, they weren't quite enough to prevent contact between the lines and the underbody. I guess the pulsating fuel flow (which depends on revs and engine load) makes the pipes vibrate. A bit more squishy foam stuffed in and the noise was gone.

Hi I am fairly confident that an LED trailer board would work, but cannot guarantee it. ideally you could find a retailer that will let you try before you buy.

Hi If you have simply paralleled up the trailer lights to the car's lights as used to be done years ago, the extra current load (if the trailer uses ordinary filament bulbs) will upset the bulb failure monitoring part of the CANbus system. You either need a dedicated wiring kit, or something that uses relays with low current coils, the extra current of the coils isn't enough to upset things. Alternatively, if the bike rack lights are all LEDs, their low current might mean that the simple paralleling approach will work.

Hi Some modern diesels use glow plugs for emissions reduction as well as cold starting. The current drawn by each of the 4 glow plugs will be individually monitored each time you start, and if out of spec (too high or low) an error code will be flagged. Even in cold weather the engine may appear to start up fine with one plug not functioning. The glow plug warning light may also be used to indicate other errors, but I have no more detail of this "error two code" means nothing to me Some error codes will be specific to VAG, and only a dealer's code reader or a sophisticated non-VAG reader may be able to interpret what they mean.

Hi Thanks to software intervention the temp gauge needle in the dash will show a solid 90 for any coolant temp in an "acceptable" range of let's say 80 to 100 degrees C. Presumably done to stop people trotting back to the dealers. Yours sounds a tad on the low side. I don't know if there are separate sensors for the ECU and the gauge. The global and cylinder air mass values might be measured in different units, i.e. grams per second or grams per stroke (i.e. revs dependent), so you can't directly compare the two exept by calculation knowing the RPM.

Thirty quid for a bulb ? Am I missing something.

Hi Fitments vary, but on my 2012 car which has no DAB or Satnav, FM reception uses both the "bee sting" roof antenna and the heated screen. The radio tuner switches quickly to whichever is giving the best reception at any time, a process called diversity. It's certainly the best FM reception of any car I have owned, so I have never felt the urge to fit DAB. For technical reasons, DAB doesn't benefit nearly so much from diversity so only uses the roof antenna, as far as I'm aware.

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 ?