Slight whine from A5 2.0L TDI

redsheeps

*I think I'm too new to be able to embed or even include links. I had made an audio recording but can't link it.

Been looking at a few 2.0L TDI A5s. Starting to think I'm either a picky so-and-so, or just unlucky as there seems to be issues with each one we look at.

Checked out a 2015 with roughly 100k kilometers. Timing belt done 2k km ago.

Noticed a slight and consistent whining noise audible in the cabin at idle that increased in pitch as the car was revved but went away over approximately 1700 rpm. It isn't a whistle and it isn't ear shattering at all, but it would get on my nerves over time.

I have a recording that sounds almost identical to it but I can't post it as I'm too new - for what it's worth, it sounds like a back boiler water pump whine (or at least it sounds like the two in our gaf).

Stupidly when popping the bonnet to look I didn't try to locate the noise within the engine bay as I got distracted by the significantly louder ticking noise coming from what I have been told is the AdBlue injector.

The whine occurred with the AC off so don't think that was causing it, particularly as it increased in pitch when the car was revved. The noise was there even after taking it for a 20 minute test run. It's not overly loud but is noticeable - I couldn't hear it when actually driving the car, only when it was stopped and idling (or revving it while it was stopped).

It doesn't sound like the turbo failure sounds that are posted on YouTube videos (I can't link the videos I came across as examples).

It's from a main dealer and I asked them to check it out. Technicians weren't there on the day, but they came back a few days later saying it was a "normal" noise, but no explanation for what is actually making the noise. The lack of explanation for the noise is more of a concern as they were able to clearly explain the ticking as being the AdBlue injector.

I had driven another identical A5, same engine (136bhp), and before I heard the noise I do remember thinking it seemed a little slower to boost and a little less powerful. Then when Googling a whine possibly being turbos has me slightly concerned it could be the early signs of the turbo going.

The car is miles away so can't spin around to check it out again but it's the best of the lot that I've looked at so before taking another drive to check it out was curious about what the noise could potentially be and/or if there's anything I should check for?

AutoGuru

If the car was stationary and not being driven you can probably rule out all things serious like gearbox trouble etc..

The likelihood is that it a bearing in one of the tensionors

redsheeps

AutoGuru wrote: »

If the car was stationary and not being driven you can probably rule out all things serious like gearbox trouble etc..

The likelihood is that it a bearing in one of the tensionors

Great shout. That got me Googling timing belts and it seems to be a common issue of getting a slight whine if the belt is over tightened, and funnily enough the dealer just had the timing belt done prior to it going up for sale.

There seem to be different opinions about such a whine. Some say it's normal and will eventually go or occurs as the belt used is 'tough', while others say it shouldn't whine and if it does the job needs to be redone.

Is whine from a new timing belt normal?

We've test drove a few of these and none of them had this whine.

Moanin

redsheeps wrote: »

Great shout. That got me Googling timing belts and it seems to be a common issue of getting a slight whine if the belt is over tightened, and funnily enough the dealer just had the timing belt done prior to it going up for sale.

There seem to be different opinions about such a whine. Some say it's normal and will eventually go or occurs as the belt used is 'tough', while others say it shouldn't whine and if it does the job needs to be redone.

Is whine from a new timing belt normal?

We've test drove a few of these and none of them had this whine.

I've had timing belts replaced on VWs & Audis and never heard this 'whine' noise....

Toyotafanboi

yeah, highly doubt it's timing belt related.

redsheeps

I took another look at it and I don't know if they tweaked something while they checked it out but I took it for the exact same test drive as the first time and the noise was gone. As the noise occurred at idle and increased when revved I gave it a few revs before and after the test drive and the only noise was some pretty solid sounding turbo whoosh when releasing the revs - didn't do this too much though as I was conscious of not wrecking it.

intellectual dosser

I'm not very knowledgeable with cars, but saw the threat title and thought I may have something to add.

I used to own a Mk 5 Golf 2.0 TDi and noticed a similar whine that generally came up traversing through lower gears (occasionally when idle). I was told it was likely an issue with the turbo - a hole in the turbo I think - and sure enough a few months later I blew the turbo out.