gm73

It’s the alternator again. Replaced it in September and it’s stopped working again. It was over compensating for not charging by running at 1k rpm. Completely packed in this evening. Strangely though the battery light hasn’t came on.

I’m not sure it’s the GPF at all. A lengthy motorway then B roads run in low gears/high revs didn’t sort it at all. Restarting the car did however and all seems well again. I’m beginning to think it’s a charging issue as this started during the summer before the alternator packed in.

This is what I was thinking. But it only started doing this during the summer. Then it stopped when I replaced the alternator and then the battery. It’s only recently started to do it again. No fault codes but live data does keep listing misfires across cylinders. I took it for a drive down the motorway and then came back over country roads in lower gears and high revs. It was still idling high.

Yes. It was coded in at the garage.

My car randomly idles at 1000 rpm - with no extra load like air con etc - just radio and a heater blower on at 4. Removing all electrical load doesn’t solve it. Restarting the car returns the idle to “normal” which is just over 800 revs. I say normal but I’m sure it’s supposed to be just under 800 rpm. It’s recently had a new alternator and battery but was doing this before they were changed. It went a while since changing those without doing it but now the issue has returned. No codes are returned via Carista. I’m stumped.

Recommended oil for this car is 0w20 VAG spec 508/509. It must be a fuel delivery issue as a blip of the throttle seems to resolve the misfire. But since it occurs only when the car is cold perhaps the fuel temp sensor is incorrectly reading. It can’t be carbon build up as it doesn’t do it at any other time.

And the issue has returned this morning. Started the car and it long cranked and went straight into limp mode giving me a P0148 fault code which is a fuel delivery error. It’s done this before as well. Restarted the car and it was fine. It’s got a brand new battery as well. I’m wondering if it’s the oil causing the issues as I’ve switched to 5w30 on the last change.

I’ve just recently replaced my battery on my 1.5 TSI. The old one had lasted 120k and was causing all sorts of issues such as misfiring from cold and stop/start not working. When weird messages and EML lights come on the first thing to check on an Octavia is the battery.

Wish I’d known that before I paid £995 in April to get it done at 118k

No oil is being used although the oil sensor is on the blink. Just ignoring that as I check the oil manually every day anyway. The battery appears to have fixed the issue. No misfires this morning and it was 2 degrees.

New battery is installed. We’ll see what happens tomorrow as it’s going to be pretty cold first thing. It began to misfire this morning as it was 2.5 degrees. I’d hoped the Archoil additive had helped but apparently not.

I’d like to update this thread. The vibration has got a bit worse. I long suspected vibrating fuel pipes but the engine is making a rattle/tick noise which increases under load. The car has also been misfiring from cold starts which may be unrelated. It drives perfectly though so I’m flummoxed. I’ve replaced the battery which was on the way out so will see if that makes any difference to the misfiring as it was cranking longer than usual.

I fixed mine but it eventually stopped working again. I think it’s time for a new motor.

I’ve got the fully paid version of Carista and a new EFB battery. Carista offers a battery registration function in the service menu. Should this be acceptable to use or will it require VCDS??

Funny you should mention the battery. It’s started to act up. The car was laid up for longer than usual and yesterday when started it idled at 1000rpm most of the day as if it was compensating for low charge. Carista said it was at 68% capacity and only a long motorway run pushed it back to 82% and stopped the high idle. Got it checked at the garage and was told the testing equipment said to replace battery. Ordered a new one from Tayna for a good price and it arrives today at some point. Which opens another can of worms. It looks like you can code the battery to the car using Carista but I’m worried about any issues.

Thanks for the input. Checking Google it seems to be highlighting carbon build up on the inlet valves as the main culprit. I’ve purchased some arch oil snake oil and will see if that will make a difference.

The electronic actuator on my 1.5 TSI started operating intermittently. Probable cause was carbon build up. My mechanic is a very honest guy who will always try and find workarounds and fixes to save me money. Unfortunately he was unable to in this instance and the whole turbo had to be replaced. There are second hand actuators on eBay if you wanted to try that as there’s nothing to lose for £35.

Hi all. I’ve got a bit of an issue with my ‘20 plate 1.5 TSI ACT on 120k miles. When starting from cold the engine begins to misfire and throws up a few codes. One for misfire across multiple cylinders P0300 and P0148 for fuel delivery issue. (If I turn it off immediately and restart it this does not occur again). Subsequent starts when the engine is at operating temperature are fine. The engine has also become a bit noisy over the past few months but still drives fine. A live data scan with Carista indicated a misfire in cylinder 2 but that went away quickly. I’m thinking that both are linked and there must be an issue with the high pressure fuel pump but I really can’t afford to fire the parts cannon at it any longer. Anyone any ideas?

Seems to be behaving itself now. Hasn't come on for a couple of days now. The car was sitting for five days so might have been an electrical gremlin.

What’s that then???😂

Fronts are really easy, piston can be pushed in with water pump pliers. Rears require a wind back tool.

Yes it’s amber thanks. Should be a sensor fault. I’m about to go under to check the wiring. If nothing looks amiss I’ll order a new sensor from TPS. Unfortunately I think you need to drop the oil to remove it. It’s close to oil change time though I suppose.

I’ve searched the forums and cannot find an exact answer to my question. I’m getting the OIL SENSOR! Please visit workshop warning message every 5 minutes or so. It pings and then goes off after about 3 seconds. Oil level is perfect and temperature is holding at about 95/96 so would anyone know what might be causing this? I’m thinking either faulty sensor, dirty sensor or a wiring issue? It’s a 1.5 TSI with 116k miles. The car is a taxi so I have to work whilst worrying about this.

I’ve done the fronts on mine twice. It’s one of the easiest jobs on a car I’ve ever done. Used Brembo parts. Cost me about £70 in total. I’ve never done the rears. Did you just use a standard caliper rewind tool???

Timing issue??