Odd ticking noise during coasting

Hello everyone,

Quite often I hear a fairly pronounced (though not loud), short-duration (2-3 seconds), RPM-dependent ticking noise from the engine when I am coasting to a stop with my foot off the throttle. The timing of when the noise seems to coincide with DSG downshifts. If this is the sound of injectors firing to rev-match the engine, then why is it so noticeable? I don't hear any ticking from the engine in any other driving situations. Can somebody else relate to this?

No ticking on mine, but I can here the DSG pre select 1st at around 5mph with a good thud

Bug Smasher said:

If this is the sound of injectors firing to rev-match the engine, then why is it so noticeable?

Click to expand...

It is not! There is absolutely no fuel being injected whenever your foot is off the accelerator, and RPMs are above idle speed.

OK, just found a youtube clip posted by none other than VeeDubTDI, that shows a recording of under-the-hood engine sounds while he is driving around the neighborhood:
http://www.youtube.com/watch?v=T4OgPfYLVVI
You'll hear the noise that I was wondering about first at the 4:34 mark, and then again - a bit quieter - around 4:39. After passing though all the noise insulation around the cabin, I guess it will sound more like the ticking that I am hearing, rather than a rattle. However, I am convinced it is the same noise because of its occasional nature, its duration, as well as the timing when it occurs (car is slowing down, DSG is downshifting). I realize that a TDI/DSG combo produces a cacophony of sounds, but still, I am curious what this is.

I listened a couple times and I can't hear any ticking besides what the engine normally makes, mind you my hearing is shot after two tours to Asscrackistan.

Good luck tracking down your noise. I wonder if it's something loose under the hood making your noise? Did you check the security of components under the hood? Just a thought.

Regards

Well my hearing isn't shot and I couldn't hear any unusual sounds around 4:34 or 4:39 that weren't present throughout the clip.

4:35 and 4:39 sounds like normal driveline noise as the transmission downshifts (to me, at least).

Didn't want to start a new thread for the same issue OP posted here. Here's a video I made by recording the engine sound from under the hood.
Video link:
1. From 1:40-1:55 and then from 2:25, there is an audible ticking. It happens only when coasting/rolling without throttle input. What could it be?

2. Do you hear any mild boost leaks?

hell.guardian said:

Didn't want to start a new thread for the same issue OP posted here. Here's a video I made by recording the engine sound from under the hood.
Video link:

1. From 1:45-1:55 and then from 2:25, there is an audible ticking. It happens only when coasting/rolling without throttle input. What could it be?

2. Do you hear any mild boost leaks?

Click to expand...

Well in the 2012-2014 Passat's, if you are in 3-6 gear and are coasting with zero throttle input. The car will not put diesel fuel into the combustion chamber, there for no diesel fuel when the engine compress the piston, won't detonate and the air will go out on the exhaust stroke. So you only hear the air escaping, the (Tic noise).

In 1-2 gear the car is too slow for this and potentially stall, so it will put diesel fuel as usual. This is an option called "Engine Braking". For some reason 2015 Passat's have this turned off. I like this feature as I just coast to a stop / use less brakes.

x1800MODMY360x said:

Well in the 2012-2014 Passat's, if you are in 3-6 gear and are coasting with zero throttle input. The car will not put diesel fuel into the combustion chamber, there for no diesel fuel when the engine compress the piston, won't detonate and the air will go out on the exhaust stroke. So you only hear the air escaping, the (Tic noise).

In 1-2 gear the car is too slow for this and potentially stall, so it will put diesel fuel as usual. This is an option called "Engine Braking". For some reason 2015 Passat's have this turned off. I like this feature as I just coast to a stop / use less brakes.

Click to expand...

Thank you!
Is this behaviour specific to NMS Passat TDI (2012-14)? I thought that's how any engine worked while coasting. Also, the ticking currently only happens when the rpm falls below 1100rpm even though I might have let go of the throttle at 1500+ rpm, is that how this engine brake is supposed to work, only below 1100 rpm?

I have owned many diesels before and have never heard such a ticking sound before. Very curious how the CKRA engine operates differently to others.

hell.guardian said:

Thank you!
Is this behaviour specific to NMS Passat TDI (2012-14)? I thought that's how any engine worked while coasting. Also, the ticking currently only happens when the rpm falls below 1100rpm even though I might have let go of the throttle at 1500+ rpm, is that how this engine brake is supposed to work, only below 1100 rpm?

I have owned many diesels before and have never heard such a ticking sound before. Very curious how the CKRA engine operates differently to others.

Click to expand...

Bump...Anyone?
Went back to the dealership for diagnosis and they do not know what causes that sound. I do not want to throw money at the car unless I have some idea what could be causing this and why.