Hi,

 

This afternoon, I started the car and I could hear some thumping noise (discontinuous and pretty low in amplitude) so I pulled up the bonnet and noticed what I think is the cam belt tensioner shaking and vibrating.
It appears that it may be the one making the noise. (Picture and videos attached).

 

A video of the problem -> (You can hear the thumping noise)

 

After driving around for a while (No difference in the drive and I can also not hear the noise) and the engine now in operating temperature, I pulled the bonnet again and the part is still vibrating the same but this time, there is no thumping noise.

 

Same part, after engine warm up -> (I believe you can not hear the thumping noise. I recorded the video in nearly the exact same conditions (phone, location etc.)!)

 

Per the service records, it got a replacement BXE engine in July, 2018 after the original one (after 9 years 6 months and 193,000km) blew it's con rods.

So I figured it had to have a new water pump, cam belt tensioner and the whole timing kit (No work on the timing has been done from then and now the car is currently at 244,000 km).

 

Any advices on what's going on here?
Is that part a pre-tensioner?

Anything obviously wrong here?

Any red flags?

I appreciate your help.

 

Thanks

 

It's normal for the tensioner pulley to move as there will be inconsistencies in the belt, the movement is it doing its job of maintaining tension.

 

The sound doesn't appear to be serious mechanical failure IMO, more like a loose mounting.

 

If you have a piece of old hose handy, try putting one end to your ear and probing with the other end to pinpoint the source.

 

Be careful where there are moving/hot parts.

37 minutes ago, MicMac said:

It's normal for the tensioner pulley to move as there will be inconsistencies in the belt, the movement is it doing its job of maintaining tension.

 

The sound doesn't appear to be serious mechanical failure IMO, more like a loose mounting.

 

If you have a piece of old hose handy, try putting one end to your ear and probing with the other end to pinpoint the source.

 

Be careful where there are moving/hot parts.

 

 

Thanks Mic. That's good to know. The engine cover and the battery cover did seem a little loose to me.
I do remember seeing someone use a mechanics stethoscope a while ago but didn't know a hose works too!

I'll give that a go.

 

Thanks again.

The engine covers can develop a rattle as the inner part becomes loose on its clips.

 

When the aux belt tensioner starts jumping its normally a failure of the one way clutch on the alternator pulley which can make a lot of noise itself, it can be tested by putting a socket or ring spanner on the centre nut, it should turn freely in one direction and lock up in the other.

 

I couldn't listen to the sounds as it was asking me for a google password.

Edited 9 May, 20215 yr by J.R.

26 minutes ago, J.R. said:

The engine covers can develop a rattle as the inner part becomes loose on its clips.

 

When the aux belt tensioner starts jumping its normally a failure of the one way clutch on the alternator pulley which can make a lot of noise itself, it can be tested by putting a socket or ring spanner on the centre nut, it should turn freely in one direction and lock up in the other.

 

I couldn't listen to the sounds as it was asking me for a google password.

Hi J.R,

 

Strange that it's asking you for a password. I tested it by opening that link in an incognito window and it didn't ask for any sort of authentication.

 

The noise isn't a lot, just some constant thumps (almost like it's sucking down some liquid, really hard to explain :/) and it went away once the engine was warmed up.
Also, the tensioner isn't jumping around, more like it's vibrating about couple of fixed points, moving back and forth (I'd say maybe less than a half a cm) of movement.
I don't have the tools on hand right now to test what you suggested, unfortunately.

Can you give that link an other try, please? Maybe in an incognito window (Ctrl  Shift + N once google chrome / edge is open).

 

Thanks

Does the sound change upon depressing the clutch pedal?

On 11/05/2021 at 11:33, MicMac said:

Does the sound change upon depressing the clutch pedal?

 

I tried it yesterday and I couldn't hear the noise much (Maybe because it was a little warmer when compared to the day I posted it).

So I can not confirm. I will check when I get a chance again.

 

When I depress the clutch or even apply slight pressure, I feel short pulses on my feet. It matches the frequency of the tick notices the PD engine makes. If I let go of the clutch and then slightly rest my foot, I don't feel these pulses.

 

I just wondered if it could be a failing DMF making the noise.

 

A pulsing clutch pedal on initial/light depression linked to engine RPM seems par for the course on the 1.9 and I've read there's an aftermarket redesigned valve or other component for the hydraulics that fix this if it bothers you.

 

I may even have posted on the matter years ago, search search search.

9 minutes ago, MicMac said:

I just wondered if it could be a failing DMF making the noise.

 

A pulsing clutch pedal on initial/light depression linked to engine RPM seems par for the course on the 1.9 and I've read there's an aftermarket redesigned valve or other component for the hydraulics that fix this if it bothers you.

 

I may even have posted on the matter years ago, search search search.

 

Thanks MicMac.

 

The DMF was replaced with the engine, about 50,000 km and 2y6m before. 
I read the post DMF Failure signs and I do not have any of the symptoms.

 

Haha yeah I will look for that post, just for curiosity. The pedal feel doesn't bother me.

18 minutes ago, MicMac said:

I may even have posted on the matter years ago, search search search.

 

Well that was an easy find! And also pretty cool that it was your first post.

 

Unfortunately, the link is no longer valid.

I cannot trace the PDF it was linking to.

 

In any case searching the internet for "VW 1.9 clutch pedal pulsing" brings up plenty to read.

 

Don't worry about it.