MOT advisory

[Avalon]

The car was MOT’d today and there’s an advisory relating to the inner faces of the front discs. They’re flagged as corroded and or scored. £600 to sort.

Garage suggests car is driven only in D mode to ensure front brakes are used (!). I always drive in D, but regardless where do VW document this, and why is there a B mode?

I now know Kia suggest a regime that you drive occasionally in ‘no regen’ mode and brake heavily a few times a month.

Bad crack from Volkswagen that a 3 year old car should suffer in this way without broadcasting something of a workaround to ensure that an owner minimises any potential problems.


A

[sidehaas]

The guy doing the MOT obviously didn't understand the car as D/B mode makes no difference to brake use in an ID3. In either mode the brakes are used if you brake harder than regen can manage. They sometimes also seem to be used if you brake out of ACC, or if you use the brake pedal when at very low speed. In any normal driving I'd have thought they should get cleaned up.

[gailjon]

I would also say that you should get another garage to look at it before forking out any money for discs.

[G43FAN]

and or scored, which is it?
Corrosion I would suggest finding a nice quiet stretch of road with good visibility and winding it up to 60mph then hitting the brakes, that should ensure the physical brakes are being used and clean up the discs..
Then take it for a 2nd opinion.

[MotMot]

I think D mode does use the brakes a little more than B - as every now and then (often at roundabouts) it seems to get a bit confused and I end up doing some actual braking (as in no regen indicated) obvs this doesn’t happen in B.

Though I seem to remember @monkeyhanger saying on ICE vw’s it auto applies the brakes very gently every X miles to wipe the discs. I’d have expected something similar on the Id3…

Anyhow - never heard of any problems with the sealed rear drum brakes! Who’s use got a slating from the motoring press… perhaps the best thing to have at the back!

[Splash-Man]

Since its only an advisory why bother doing anything about it ?
I've had similar on my ICE for a number of years and its always an advisory but never a fail. Feeling near the sea means there is always some sign of surface corrosion.
As suggested, an Italian tune up before taking it in for a MOT test sorts out the problem.

[gailjon]

I will have to have a little 'extreme braking' in the wife's ID3 when before we take it to MOT next month.

[sidehaas]

I will have to have a little 'extreme braking' in the wife's ID3 when before we take it to MOT next month.

I have another car, an Octavia with nearly 100k on it, which has had advisories for corroded rear discs in its last three MOTs (they both corroded badly when the car was just sat on the driveway in the first lockdown). Each of these years I have driven up and down the motorway on a quiet night in the few days before the MOT, braking very hard from 70 to 40 repeatedly to get rid of a layer of corrosion. On the last occasion only a month ago, something changed in the feel of the brake under heavy braking and ever after that I could hear a light grinding noise whenever I braked. I was convinced I'd either broken something or gone right through a pad to the metal.
The garage looked at them all at MOT (I told them what had happened, it was basically an invitation to charge me for work), but they just gave me the usual advisory on the discs, told me the pads would need doing soon but not yet, and everything else was fine. Unfortunately the brakes are still making that noise and I have lost some trust in them, so will probably end up paying another garage for a second opinion before I go anywhere far in the car.
Moral of the story, don't brake too much/too hard to clean your discs!
Our ID3's front discs have remained bright and shiny throughout its time with us.