Alasdair1

Had same on old volvo 940. One of the rear pistons was sticking at a certain point but not seized. New caliper and discs/pads and back to normal. Volvo had two pistons one each side of disc so when braking only one was working and pulling it out of alignment. Not sure on the superb but if a brake shoe is seized in its carrier it will do the same as well as a seized slider pin/pins. Reckon it needs wheels off and check the pads and slider pins plus check there is no drastic run out on discs Alasdair

Not sure re PR codes from vin. Have tried a few places online and no luck. Your lucky you have one code. I have three skodas and the brake codes are all missing including a Seat. You could try https://www.lllparts.co.uk/catalogs and put in the VIN it might narrow it down for you. As far as I know there are two sizes of discs for front if you have TRW calipers. 288mm or 312mm. The other option fitted is Kelsey hayes calipers which have 276mm. Reckon it might be safer measuring. You would only have to take one wheel off. Alasdair

Have you an aftermarket radio. Quite a few folks on here having trouble reading ecu etc. For some reason the after maaret radios affect can-bus and can stop any communication. If your pedal is going straight to floor I would suspect a bad master cylinder thats letting fluid past the seals or a major leak somewhere. Is the brake fluid level ok. Check the rear drums if fitted for signs of fluid at bottom as my sons mk1 wheel cylinders were shot and leaking fluid. Alasdair

It maybe a bad connection or broken wire to bonnet switch or failed bonnet switch itself. I read on a vw forum that you can use vcds to reset it if bonnet switch wont. A bit above my comfort zone at moment but as follows from vw jetta You need to Recode cluster . address 17 07= fourth digit in the coding: 0 = vehicles with fixed service intervals without oil/temp. sender 1 = vehicles with flexible service intervals with oil/temp. sender 2 = vehicles with fixed service intervals with oil/temp. sender 3 = vehicles without service interval display (USA, Canada) So I assume you have to change 07 to one of the above Alasdair

Sorry read it wrong. I think it needs further investigation fairly quickly. Any oil warning lights need to be checked out even if they are random. Could be as said oil too thin (diluted) or partly blocked strainer etc or hopefully bad sensor Alasdair

Just realised the oil light is flashing before ignition which may point to a bad sensor or wiring. As said P242F is restricted dpf and I would get the oil sensor checked ASAP including DPF pressure sensor. Check your airfilter as well. Alasdair

I get P242F as DPF seriously restricted. The oil pressure light may be coming on due to oil being diluted with diesel due to multiple failed regens. Someone on here had same problem and theirs had diesel runaway that luckily stopped when engine was switched off. It would also explain why oil level is slightly high. I wouldnt drive until garage checks condition of oil and if its not regenerating the dpf properly. Could be a bad sensor thats causing failed regen. Alasdair

I would take it back to the garage that changed valve etc as its a repair that didnt cure problem. It could be the charcoal cylinder itself but first try another filler cap. Have read if they don't seal properly can cause same code. Alasdair

Something is definitly not right with c3. If it was the rings etc you should have had an improvement. Reckon HG has gone on c3 and maybe tracked slightly to C4. You could try a pressure leak down test to see if you can hear compressed air leaking or guage drops quickly. Each cylinder at TDC and I think its around 100psi From memory there is some normal air leakage of around 10% but with those readings unless its a valve spring I reckon head has to come off. Another thought before removing head is try some soapy water around inectors etc and look for bubbles when cranking just in case its leaking there but think it would be noticeable with the low pressure readings. Alasdair

My pedal seemed soft and sunk a bit but difficult to tell if it was sinking or just spongy. It didnt feel right. If you used a gunsons kit I would have thought it would have cleared the air unless its stuck in ABS and may need VCDS to bleed properly. Check every one for slight leaks as well as flexi/brake lines etc as a slight leak somewhere will cause the same effect. It may not leak until under pressure. Alasdair

Had similar problem on mine and suspected air somewhere that wasnt coming out with manual bleeding. I got a Gunsons pressure kit and after a while a large bubble came through and brakes were back to normal. Not sure where the air was trapped but definitly not ABS as kept fluid high at all times. Wonder if theres a brake compensating valve for rear it was stuck in. Alasdair

Do a dry compression test and note readings. Then add a little oil to each piston and do another. If the results are a good bit higher after oil it may be a piston ring problem. If nothing changes much then its probably HG or valves. Hope its something fairly simple. Have had broken spring on valves before and got misfire plus very low compression. Garage managed to repair with head in place. They fed soft string into sparkplug hole and turned engine over carefully and using piston to jam valve and managed to compress spring to replace. Alasdair

The oil in throttle body and blue smoke as you say in bits so I assume its not all the time. My old volvo 940 used to do the same re smoke. If it was idling for a while when I took off it produced blue smoke due to seals failing in turbo which cleared once driving. The intercooler on mine was full of oil. It may be that the smoke and misfire are not related and are coincidence but the low pressure test reading does point to HG or valve spring/seating problem. I would redo the pressure test to make absolutely sure. I normally remove all plugs so engine spins at max speed. If its the same then further inspection of head/valves I think is required. It may be that the valves on the cylinders that are low and lower are carboned up so not making a good seal especially c3 or as said weak broken springs. Check the coolant level plus check for any signs of oil/bubbles in coolant. Alasdair

C3 and C4 are way down especially C3 at 20psi . It could be a failed HG on C3 and maybe C4 but it could be a broken valve spring or burnt out valve etc. The misfire will be down to poor compression on 4 and no compression on 3. Unless theres an obvious broken valve spring I reckon head may have to come off to check. Alasdair

Could be as you said a vacuum leak . Check the pipes from servo for cracking etc. If you pump pedal with engine off till hard and keep foot on pedal and start car if the servo is working the pedal should drop slightly. It may be a slight leak that once the car is running its generating enough vacuum to compensate for any leakage. Meant to add if the pump is electric check the wiring to it plus any related fuses for looseness/corosion. Might be worth getting it scanned to see if there are any stored codes that could point to the problem. Alasdair

If you go to the link above and check fitment it gives you a fair list of vw,seat and skoda cars it fits. Might help widen down your search at breakers etc. Alasdair

Glad it was the sensor not the DPF. Read it can be a fairly common problem. Alasdair

If its on one side I would either jack it up and check bearings for smoothness etc or pop into the garage you use and get them to check. A failed bearing will get progressively worse as will the prop. To be on the safe side I would get it checked out in case its low on diff oil or the haldex unit is needing serviced. Bearings are relatively cheap as is prop junction but Haldex/diff will not be. Alasdair

Doesnt take much to make a bad connection and cause voltage drop. At least if it does it again you can rule out what you have done. Alasdair

Meant to add if you think its transmission/haldex then maybe a gearbox oil level check and also a haldex service including rear differential oil. Could be a clogged haldex filter causing pump to work harder. Alasdair

Is it a transmission whine or perhaps a bad bearing. Try turning slightly left and right when driving. If its a bearing it may change pitch or get less when turning. Alasdair

Something else to check may be the cam position sensor. Perhaps its failing/sending wrong info at revs above idle. Have had some fail without creating codes. Alasdair

As there are no codes it may be a leaking PCV/air intake or carbon build up on valves. I would have said coil packs first but again no codes/misfires and they have been replaced. It might also be a dirty throttle body but I would assume it wouldn't idle properly. Alasdair

Might be a faulty DPF pressure sensor/wiring. When towing the engine will be under more load so may be getting confused and sending wrong signal or due to towing at lower speeds with engine under more load it may not be regenerating properly. Might be worth getting it scanned with vcds and also check soot/ash levels etc. Check exhaust system for leaks as well. Alasdair

Chances are that Skoda may have come across this before and will be able to change it. As said my old garage changed my folks one but not sure how. They did not have vcds but may have got someone in with it. Alasdair