[Malkolm]

Hello I have a strange sound in my Golf 2.5.

This is a clack clack clack clack type sound that started a year ago when winter arrived ( I am in Canada).

The sound disappeared during summer and slowy came back last month (temperature under 5 degree C).

The sound is present when I am not moving and not pressing on the clutch pedal.

If I press the clutch pedal or the car is moving there is no sound.

If not moving and press the gas pedal, the clack clack clack clack type sound goes faster.

Like I said it seems to be function of the temperature. I drive 30 minutes and it seems less strong.

I did not noticed it at all between May and October.

Did someone experienced the same thing?

Thank you

 

[guggles]

Lifters are noisy on the 2.5 but it could be the acc drive

 

[Malkolm]

Lifters are noisy on the 2.5 but it could be the acc drive

Why would these react with temperature?
I don't use the ACC Drive.
Thank you

 

[Malkolm]

Also it is not noisy when I am driving, only when I am not moving.

 

[BoomerGuy]

Also it is not noisy when I am driving, only when I am not moving.

Not moving and in gear vs in neutral or park? Are you sure it is the engine and not the transmission?

 

[Malkolm]

Not moving and in gear vs in neutral or park? Are you sure it is the engine and not the transmission?

It sounds when not moving and neutral. If I am in gear I don't hear it. It could be transmission I don't know how these work together. What could it be in the transmission?
Thank you

 

[ChefroA6]

Secondary Air Injection pump?
You might have a broken plastic hose and since it sucks in constantly cold air, the SAI runs "constantly" to inject back into the system exhaust "warmed" air. It is normal to hear that on every cold start in the winter, but not running for a long time.
If that's the source of "noise", then you should probably inspect your air pump system.

 

[maxeymum]

The sound is present when I am not moving and not pressing on the clutch pedal.

If I press the clutch pedal or the car is moving there is no sound.

Could be throwout bearing or maybe worn flywheel. I'm no expert on these things but if the sound goes away when you press the clutch that's a pretty good clue it's something in the clutch assembly. My '10 Golf makes a slightly 'thumpy' sound when it's idling and the clutch pedal isn't depressed. The noise stops when I depress the clutch. It also goes away when clutch is engaged as the car warms up and is driven. I did a little research on this and a few people said that their car has been doing the same thing for a long time, and not to worry about it. My approach is that when the car needs a new clutch it can be addressed at that time. So long as the clutch engages correctly and isn't slipping yours is probably fine also.

 

[Malkolm]

Thank you for all your answer. I was thinking of the clutch too but if it does not happen in summer, I discarded it.

 

[FlatBlackDog]

If the SAI lines were cracked, the CEL would be on and the car would throw a P1424.

Since the sound only occurs in neutral in no load conditions, and it is not a squealing, grinding or oscillating sound, it is less likely to be the throw out bearing. Typically, a failing TB would get louder as you put pressure (load on the bearing) on the clutch pedal. This does not completely rule it out, but the sound you describe makes it a lower priority in terms of possible sources.

It could be the input shaft bearing - That would be a grinding, whirling, or chirping sound when the transmission is in neutral, but the noise goes away when you depress the clutch pedal. However, I've never heard of it going away as the car warms up.

I think you have at least one loose clutch plate spring. One might be cracked which could be more of a problem, but I don't so based on experience with a couple of older porches I've owned. Older clutch plate springs can click when in neutral under no load. The springs are made out of a different material than the housing and wear as they age. When its cold, the spring shrinks and has more room to move and makes more noise until heat from use (shifting) and transfer from the engine warms them and they expand. See the video below to hear what the clicking sounds like out of the car on the bench.

If you are concerned about the gearbox / input shaft bearing, have the gearbox drained and filled. VW suggests the gear oil be changed every 30 to 60k. Have the tech use a magnet in the drain pan to look for metal shavings. Bearing metal has a unique look to it. I had a 968 eat its main bearing due to Audi over-torquing it before delivering it to Porche. It was like panning for gold.

 

[Malkolm]

Thank you again for the answers. I will bring it to the shop next week to see what they have to say.

 

[guggles]

Mileage on the car? And clicking noises can come from a lot of different places. If your sure it's dependent on engine rpm and happens when the car is in neutral only then looking for the noise from the engine or transmission is a good place to start

 

[Malkolm]

The car has 160 000 kms