Right, lads, I’m at my wit’s end with this one. I’ve had an ongoing knocking (deng deng) noise coming from under the bonnet on the driver’s side, and despite a few fixes, it’s still there!

Here’s what’s been done so far:

• Front suspension mount replaced today – advised by Halfords Autocentre despite them being only 11 months old. Noise still exists.

• Track rod end was stuck, threads damaged, so it was replaced too.

• Timing belt was changed few months ago (6 to7months) –

The noise is very obvious, happens even at slow rolling speeds, and feels like it’s coming from somewhere under the bonnet. Garage guy is struggling to pinpoint it, which is driving me nuts!

What could it be? I’m thinking:

• Engine mount?

• Timing belt tensioner or pulley issue?

• Something loose in the aux belt system?

• Heat shield rattling?

Appreciate any guesses or advice – need to get this sorted before I lose my mind! Cheers!

Handy if you just say what the car / engine is and not have members need to look at your profile to see a 1.4 TSI DSG 2017.

How many miles done now?

Is this the same car that has had many many various issues?

If a Mechanic or Technician with the car can not find the source of the noise then guessing is all that others can do.

Giving them all the info there is helps a bit.

Edited 18 March, 20251 yr by Ootohere

Does it do when coasting with the engine off?

8 hours ago, Ootohere said:

Handy if you just say what the car / engine is and not have members need to look at your profile to see a 1.4 TSI DSG 2017.

How many miles done now?

Is this the same car that has had many many various issues?

If a Mechanic or Technician with the car can not find the source of the noise then guessing is all that others can do.

Giving them all the info there is helps a bit.

Mate, appreciate the input, but no need to get snarky. If someone’s genuinely interested in helping, they’ll ask if they need more details rather than having a dig. That’s how forums work, isn’t it?

I’m not just here to get a definitive answer – I know no one can diagnose a car over the internet. But sometimes, someone with a similar issue might chime in with a useful clue, which could lead me in the right direction. That’s exactly why forums exist – to discuss, compare, and troubleshoot.

If you’ve got any constructive ideas, I’m all ears. If not, maybe let the thread run its course – you never know who might have the missing piece of the puzzle.

1 hour ago, ords said:

Does it do when coasting with the engine off?

Yeah, the noise is constant – even when coasting at low speed, it keeps going. I’ve got another check-up booked, so hopefully, I’ll get to the bottom of it. After all, I love my car and like to keep it in top shape. I don’t let even the smallest issue slide!

Appreciate the input – will update once I’ve got more answers.

Edited 18 March, 20251 yr by automass

That would seem to rule out anything related to the engine then.

Can you post a video or audio file of the noise?

Are you now saying the noise pattern is related to wheel rotation speed and not engine revs?

If it's not rotational as Gerrycan has asked, could it be your bonnet knocking on its stops or at the latch?

Drop links creaking? Bonnet release cable rattling? Radiator nice and firm?

Can you make it do it while stationary - someone in the driver's seat, the other bouncing the car?

Can you replicate it without rolling, but taking up drive and then letting off, so rocking the engine with its own energy?

Gaz

If the knocking noise is related to wheel rotation does it vary with acceleration or on extreme lock in either direction?

Universal joint wear?

Rarely reported on VAGs but since we still don't know the car mileage or whether it is subjected to a lot of full lock maneuvers like a taxi driver would likely do?

I have this knocking sound also at my Skoda 1.4TSi 2012 ( see bellow link) . What could be the source of this bad sound?

The time chain kit was changed recently and the HFPP pump is also new.

On 18/03/2025 at 21:56, ords said:

That would seem to rule out anything related to the engine then.

Can you post a video or audio file of the noise?

Yeah, it’s definitely not engine-related. The noise only happens when the car is moving, even at slow speeds like 5-10mph. I’ll try to get a recording if i can.

Edited 20 March, 20251 yr by automass

20 hours ago, Gerrycan said:

Are you now saying the noise pattern is related to wheel rotation speed and not engine revs?

Yeah, it happens when the car is rolling, but it’s not linked to revs. Even if I just let the car coast at low speed, I get this rattling ‘dheng dheng’ sound from the bonnet area.

9 hours ago, Gaz said:

If it's not rotational as Gerrycan has asked, could it be your bonnet knocking on its stops or at the latch?

Drop links creaking? Bonnet release cable rattling? Radiator nice and firm?

Can you make it do it while stationary - someone in the driver's seat, the other bouncing the car?

Can you replicate it without rolling, but taking up drive and then letting off, so rocking the engine with its own energy?

Gaz

Nice points picked up. you are a genius. I didn’t even think about some of these! Bonnet latch could definitely be a suspect, I’ll check that. Drop links are fairly new, and the radiator feels solid. fan is bit shaky, but i don't think it is coming from radiator fan. The noise doesn’t happen when stationary, even if I bounce the car or rock the engine, but only when rolling at low speed or bumpy road, definitely. Could be something knocking around under the bonne.

Edited 20 March, 20251 yr by automass

33 minutes ago, cudalbgeo said:

I have this knocking sound also at my Skoda 1.4TSi 2012 ( see bellow link) . What could be the source of this bad sound?

The time chain kit was changed recently and the HFPP pump is also new.

Listened to your video. Your noise sounds more engine-related. Mine’s more of a bonnet-area rattle when the car is rolling at low speeds. Could be something loose or knocking against a panel.

It sounds like a loose metal cover. Can you make sure that the covers over the exhaust manifold are all tight and any covers around the turbo are also all tight.

Check the bonnet hinges for play when shut. I had an annoying rattle on my MX5 that turned out to be a worn hinge that was rattling slightly.

Massive thanks to everyone who chipped in with their thoughts—really appreciate the input!

Had the car checked over at a garage, and they went through all the suspension components and bushes while it was up on the ramp. No obvious faults were found, and apparently, the noise isn’t coming from the bonnet latch or any of the other suggestions put forward here.

The garage lads were stumped, so I decided to take matters into my own hands. Started pushing down on the front right side to side to replicate the noise and that’s when I finally heard the clicking noise. The more pressure I applied, the more it made that exact sound I’ve been talking about.

Back on the ramp for round two, this time with an even more thorough check. But still—nothing. In the end, they just told me to drive it until it gets worse. Not exactly reassuring, considering most of the suspension components are new.

So, here’s the big question—how on earth do I pinpoint the dodgy part? Anyone got a trick up their sleeve for this sort of thing?

Cheers again for all the help!

I think you need to take your car to a VAG specialist. Driving it until it gets worse when there is already a mechanical noise is not good. So - suspension components were replaced. Are they genuine OEM hardware or third party?

Usually shock absorber if your struggle to find the noise, has it ever had and springs fitted or work to the suspension? Wheels bolts tight??

Hi. I found the source of the noise on my engine. I put back the old HPFP, and the noise disappeared.

The pump PIERBURG has a different rod length than the original pump, with ~4 mm, so the spring and cam follower jump inside, creating this noise.

https://youtube.com/shorts/j69FljyDDhw

Check the strut top nuts are fully tightened. Mine was knocking after strut change and turrned out the strut top nut had come slightly loose or wasnt tightned properly. Wouldn't do it unless the car was moving.

After replacing the ARB links on both front wheels, the noise is pretty much gone now. There's still a slight rattle from a panel or something, but it's nothing major – totally bearable.

On 25/03/2025 at 00:51, automass said:

... or any of the other suggestions put forward here.

11 hours ago, automass said:

After replacing the ARB links on both front wheels, the noise is pretty much gone now.

Cough..... errrr....

On 20/03/2025 at 10:07, Gaz said:

Drop links creaking?

Gaz

Glad you got it sorted 👍

Gaz

Edited 6 April, 20251 yr by Gaz

They are worse than mine and they were bad. I seem to go through them quite a lot. Check the bushes in anti roll bar as well. Mine looked ok but decided to change them anyway as I still had a small knock sound. They were pretty poor once I removed them.

Alasdair