Noise detective: episode two

The image displays the speedometer of a Skoda Octavia, showing the yellow icon of the engine, indicating the presence of some issues.

Finally I found some time to write down the second episode! For those who wish to read the first one, here the link

How much to repair?

I have been waiting some news from my usual retailer regarding the cost of repairing the differential. During the second half of January I finally received the “official” answer: the price of the differential is of about 5’000 CHF. To the already high cost of the mechanical part I should add the work needed to make the repair: the total amount goes up to 6’300 CHF.

In the meantime the noise did not change. Sometimes, mostly when I leave the car rolling, it changes tonality and seems to be louder. Funny enough, if I drive faster than 100 Km/h, maybe around 130 Km/h, the noise fades almost completely.

TCS: a neutral point of view

Given the high cost of the repair I thought it would be a good idea to have the Swiss Touring Club (TCS) double check if the noise was really coming from the differential. Past Saturday I took the car to their workshop and after some routine checks we put the car on the auto lift: I stayed in the car and once it was high enough for the mechanic to stand below it, I started accelerating as agreed with him. It was quite strange to be “in the air” giving gas and changing gears. Around 100 Km/h the noise is the loudest and once I reached that speed I told the mechanic to start listening: he went below the car and with help of the stethoscope he was able to recognise the noise and to define that the noise was coming from the right end of the differential.

It was really helpful having a neutral point of view. And of course, although I would have preferred that the answer was something different, possibly less expensive, I am now happy to have the source of the noise confirmed. The whole operation, being member of the TCS, cost me 50 CHF.

Worth speculating?

Every mechanic I speak to tells me that it is very unusual for a differential to brake down. This led me to play with the thought, that maybe it was just a dose of bad luck and that actually, although an expensive repair I might have luck for the next years to come. Spending 6’300 CHF is still way less than 40’000 CHF for a new car. And as the car itself is still looking absolutely good I am kind of recalcitrant to change it. Also, as I use the car to go to work, reaching almost 35’000 Km per year, I do not want to invest in a new one. Ideally today’s car would be awesome.

But… a few days later, I got proof that my thinking was too optimistic: the emission control light turned on. Of course this happened the day before leaving for a business trip of about 4 hours drive. I decided to swap car and use one which the company has at disposal for such events.

This is the symbol of the emission control.

Once back from the trip I took the car to the mechanic: in 30 min time he was able to tell me that the issue is most probably related to a fan not working properly in the exhaust vent. Nothing to worry about. Still, in case it would turn on again I should consider changing the exhaust vent, with and estimated cost of about 1’300 CHF. I drove to work hoping not to see the light anymore.

But there it was! In the evening, as I started the car to drive back home the yellow warning light was staring at me, with a rather static expression! Oh well… between the noise in the back and the yellow light in the front, for sure I was not feeling alone!

Now what?

Given the value of the car which is around 10’000 CHF everyone is suggesting to leave the car as it is and to buy a new one and I am seriously taking into consideration that option. I believe that all in all I am going to stay with the same model of car as love the roomy interiors and the big trunk, but I am seriously considering to change from diesel to the natural gas engine. 2019 version is a 1.5 L with 130 HP which should be enough for my driving style. In a few weeks I should have the possibility for a test drive: I guess it will be the topic for our next episode?! 😉

Noise detective: one more episode!

Noise madness

I have noticed that I get somehow “attracted” by noises that might be indicators of something not working properly. For example, I already bored all of my followers about the noises of our heating system. And trust me, the ones that I manage to write about are the ones that give me to think the most: there are many, many others noises that get me suspicious that I do not write about, yet intrigue me as I am sincerely worried about the fact that whatever the mechanism is, is not working as it should.

Celestona and the 500’000 km bet

In this “episode” the protagonist of the noise is Celestona, our family car. It is a 2014, all wheel drive, Skoda Octavia. The engine is a TDI, 2.0L, 150 PS. I use it for my daily commute and from April 2014 until today I have collected almost 175’000 km. Mostly motorway.

I have bet with myself that by driving safe and carefully I could bring this car up to 500’000 km without suffering major break downs. The bet might seem crazy, to me though, it seems fairly possible as I am driving always on the motorway, trying to respect all the speed limits and saving as much fuel as possible. This brings be to drive like an 90 years old grandfather with speeds not exceeding 105 km/h… unless I am very late for work. 😀 The question is… will Celestona make it to 500’000 km?

The noise

Let’s get into it!

It is very difficult to describe it in writing. If someone already has experience with ballbearings slowly wearing out… that is the genre of noise. It could be also exemplified by the rolling of very deep profiled tires as in off road cars (e.g. jeeps). I can hear it coming from the back of the car, it starts already at 50 km/h and changes tonality while speeding up. But it does not get louder or unbearable, it just changes its “voice”. I have been hearing it since months now: as I had it classified as a ballbearing being worn out I did not feel the urge to go to the car dealer and have it repaired.

First tests

The first test I did was to wait out. I started to notice the noise during the end of the summer and I decided that I should wait for the change of the summer tires into winter tires. This way I would understand if the culprit were the tires or something else. I did the change of the tires in November: the noise was/is still there.

Posterior right ballbearing?

I kept my noisy companion for one more month until it was time for the 180’000 km service. This was my occasion to have the ballbearing changed! From an organisational point of view it was a great idea as I could take the car just once to the dealer and have the service as well as the noisy issue solved.

As usual, the Volkswagen team is very efficient and in one day my car was serviced and the rear right bearing substituted. Fantastic.

I was less enthusiastic when driving home I noticed that the noise was still there. It was quite a big disappointment realising that the car had not been tested after being repaired: in my naive mind it should go without asking that repairs should be checked once executed.

But then… where is the noise coming from?

Having changed the posterior right ballbearing, my suspects were on the left one: I asked to Volkswagen mechanics to double check that.

I took the car once more to the dealer and during the afternoon Marco, my reference person in Volkswagen, called and informed me that in their opinion it was not the posterior left ballbearing the culprit: the differential was it instead!

Pricey stuff

Changing a differential is very, very expensive. When I got the news I was definitely sub enthusiastic. Marco confirmed my fears by anticipating me, that the differential by itself would cost 5’000 CHF. To that I should add the cost of the work for changing it.

I quickly did a research of the on to have at least a feeling of which is the market of value of my car on the Swiss market. Around 12’000 CHF. Given the market value and the cost to change the differential the “new car scenario” started to show up. Not only that, but also the “I have lost my 500’000 km bet” scenario showed up… It is a personal challenge, so nothing serious. But somehow I was disappointed!

Not the last word… yet!

After a few hours of overthinking the matter I took the decision to have a second opinion of another mechanic. I took the car a Skoda dealer very near my work place, together with the mechanic we took her for a quick spin and guess what?

In his opinion the possible culprits are two: either the tires or the ballbearings. Considered that the tires have already been changed once and that the noise stayed there, we have a second opinion indicating the posterior left ballbearing.

Very important is the fact that the mechanic defined a faulty differential as not an option as it would sound in a very different way, if it was damaged in any way. Another thing that reassured me was the fact that the differential is not in use at all when the car is driven at motorway speeds. Basically it gets activated only if the front wheels slip. If they do not slip it does not get even connected.

In conclusion we decided that I should keep the car as it is. The noise should worsen and make it easier to understand whether the source is the posterior left ballbearing or something else!

And that makes me happy…: the bet is still going! 😀


There is one thing that keeps my mind grinding: why has my usual Skoda dealer, Marco, told me that the differential should be changed? What was the issue they noticed?

As soon as I have more news I will create a second episode and keep you posted about who was right… 🙂

Should anyone have suggestions regarding the matter… please let me know!

Have a nice afternoon!