Warrior193

Possibly worn syncro hub in gearbox - do the gears also make a 'clashing' noise when you get this whine? Do you know how to double-declutch when changing up a gear?

Unfortunately, even to unlock the drivers door via the (concealed) emergency lock cylinder will require the spare key.

I have seen recent postings from another TDI owner with identical issue - resolved by replacing the faulty battery. Have you had the battery tested?

Hello MILF, welcome to the forum. Strongly recommend a proper battery test. The control modules on these vehicles appear to be very sensitive to low voltages from a failing battery. What is your fuel type and engine code?

Was the old battery the same type and capacity as the one currently fitted? There is an adaptation required in the BCM, ideally every time a battery is replaced - especially if the replacement is different from the original. Critically, is the present battery a EFB or AGM?

@9737u50 - varying alternator voltages are normal with the micro-hybrid energy system, with battery charging intended to be primarily from energy recuperation during coasting and braking. The battery will typically be charged to around 75-80% by the alternator using engine power - leaving capacity for energy recuperation.

Hello, welcome to the forum. If your battery tests as OK - and your alternator voltages look good, I'd suggest that there is something not 'going to sleep' correctly after you shut down. Check the forum for parasitic drain on battery. The noisy fuel pump should not be the cause (unless it keeps running after engine shut down) Were there any changes made to the vehicle around the time this problem started?

Alcohol has an affinity to water. Dosing fuel with alcohol makes any excess moisture it contains miscible and is then burnt.

Hello @red2 To edit a post, click on the 3 dot symbol at the top RH side of your post - you get an option to report, edit or share the post.

I think the VW one that fits the Octavia3 is purely for aesthetics, from what I've seen, the one on the MkIV is more for sound-deadening.

@Hamlet5 I didn't note that you had a VRS with IRS - I saw the beam axle image in 2nd post and thought you were referring to that type.

At the risk of showing my age, I seem to recall once reading that if a new RR engine didn't use a specific amount of engine oil (IIRC, 1 pint in 1000 miles) the garage recalled it to rectify the problem.

@fuzzybunny Have you tried putting into gear with engine stopped, then starting it? Make sure car is not likely to hit anything if it does lurch forward if it starts then stalls.

There are comments on Honest John for Dipethane (presume same stuff) dating back to 2013 - most seem to consider it 'oil of snake variety' Main use would seem to be eliminating water in fuel - if that was an issue, Iso Alcohol would be cheaper.

@Hamlet5 are you sure that's a good idea? That could significantly change the twist-rate of the beam axle.

Although it is specifically not recommended nowadays, I do use a very light smear of copper-ease grease on both the wheel bolts and the hub to wheel mating surface - and use a torque wrench to tighten correctly. I have never had problems with either.

And there was me thinking my 7 yr. old Moll EFB was doing OK - but, then, it is a Moll 🤔(presumably not one of the duff ones)

Hello Mike, welcome to the forum. Apologies in advance for asking the obvious question - has a full brake system bleed been tried? From my understanding, bleeding modern brakes is not necessarily a simple job when attempting to clear the ABS module.

Don't forget to allow for inrush current of the solenoid valve - likely to be much higher than holding current.

Fair to say that the old battery has done pretty well. For the record, do you tend to use the stop-start function most of the time?

As OPs car does not have stop-start - and therefore is not a 'micro-hybrid' would it also not have the energy recuperation system? - In which case, EFB battery should be OK (but pricier) to fit.

Does your car have stop-start (is the battery EFB/AGM) type?

Thanks, that's really good to know, I have had this issue with my clutch pedal very occasionally, which then clears for long periods.

It is likely that a silicate dispenser of some description was fitted originally. Have you owned this vehicle from new?

I believe the issue with some LEDs can be electrical 'noise' There is often a date stamp (YYMM) on one of the battery posts. Correction - the date format might be MMYY.