Nothing jumps out at me as sounding different to mine; but I'm not a mechanic

 

What did the garage say after they'd had it overnight?

Sounds better than mine! 

1 hour ago, Solarstorm said:

Nothing jumps out at me as sounding different to mine; but I'm not a mechanic

 

What did the garage say after they'd had it overnight?

Car has yet to go in overnight. 

 

Sorry to bore you both @Solarstorm @silver1011, you need to listen to all stop start acceleration once I got off the drive(few minutes in). The chatter definitely comes in at the times mentioned where it's not there any earlier driving from home. 

 

2 more observations 

 

1. It did it at 4pm from work after being parked for 8hours, note it's not been as hot today as has been lately in the afternoon 21 degrees some days the car has read 28-31

So is it linked to being cool rather than hot?

2. I called the old owner who experienced no such issues, but I do note the last 4 service receipts list down an engine flush. Nov16, May16, Dec 15 and July 15. 

 

I have read some threads on to flush/not flush engines it's a mixed bag, but perhaps once you start using the stuff you need to carry on?

 

37 minutes ago, silver1011 said:

Sounds better than mine! 

I really have noticed how quiet it is inside and listening to the DSG changing up in the early hours is quite nice. Compared to the old faithful 105 PD and even older diesels I have owned.

You have to open the window or door to hear the engine noise at tickover to remind you it's a diesel. Again from inside the cabin it's like driving an old merc auto, just gear changes can be heard unless you really go for it. 

On 13/07/2017 at 20:17, SuperbTWM said:

Its just the slack in the valve train you can hear until the lifter gets some oil pressure in it.

 

I honestly believe this is the cause on my car. It's only ever from a cold start, doesn't appear immediately, perhaps 30 seconds to a minute after setting off and only lasts a few minutes/miles.

39 minutes ago, silver1011 said:

 

I honestly believe this is the cause on my car. It's only ever from a cold start, doesn't appear immediately, perhaps 30 seconds to a minute after setting off and only lasts a few minutes/miles.

Well I am kind of happy if yours is doing it, can you check it only happens say 1500-2000rpm under load?

I just wanna be sure. Perhaps you could send a recording over for me? We both do similar style of driving albeit different CR engines...

The risk of ignoring something mechanical is some major component failure in my mind. And rather than pay a garage time to look at something that's normal, I would rather gather the opinion of some fellow Briskodians.

I do wonder where this noise was since purchase, but enough has happened since then and perhaps the car is normal now. 

Its hard to say if it only does it between 1,500-2,000rpm. It is certainly most audible at that range, I suspect it is still present at higher rpm's but the noise of the engine hides it.

 

My commute involves a short 20-30mph run off the estate (2-3 minutes), round tight corners and over speed humps. This is when I can hear it. After that I'm up to 60mph on country roads and it isn't heard again for the duration of the journey.

1 minute ago, silver1011 said:

Its hard to say if it only does it between 1,500-2,000rpm. It is certainly most audible at that range, I suspect it is still present at higher rpm's but the noise of the engine hides it.

 

My commute involves a short 20-30mph run off the estate (2-3 minutes), round tight corners and over speed humps. This is when I can hear it. After that I'm up to 60mph on country roads and it isn't heard again for the duration of the journey.

Same for me few local roads for 5 mins then at motorway speeds. At the weekend doing more small road journeys it did it a lot more, really worrying as it's metallic 

I know that noise very well, and I was told by the Skoda technician that the noise the CR system under load. Our CR170 does it some days and not others and it can be much worse than your recording. I'd describe it a bit like the old pre-ignition sound I used to get on my Mirafiori Sport when accelerating and was really hot and the mixture was too rich. 

I'm away at the moment and I have Renault Captur DCi rental car (which is a gutless piece of #~% btw!) and it's continually making that exact noise when I accelerate. The Renault Kaptur DCi (also %#<&) I had here last month made the same noise too, as did the Megane GT DCi (which was very quick.... but awful quality) I had in April and the truly awful in every conceivable way, Renault Fluence (seriously?) I had before that also made it. 

 

I found this old thread thinking it was about my other noise at tickover when warm. It could be what we we described above. Seems to deviate slightly 

 

2 minutes ago, numskull said:

I know that noise very well, and I was told by the Skoda technician that the noise the CR system under load. Our CR170 does it some days and not others and it can be much worse than your recording. I'd describe it a bit like the old pre-ignition sound I used to get on my Mirafiori Sport when accelerating and was really hot and the mixture was too rich. 

I'm away at the moment and I have Renault Captur DCi rental car (which is a gutless piece of #~% btw!) and it's continually making that exact noise when I accelerate. The Renault Kaptur DCi (also %#<&) I had here last month made the same noise too, as did the Megane GT DCi (which was very quick.... but awful quality) I had in April and the truly awful in every conceivable way, Renault Fluence (seriously?) I had before that also made it. 

 

Really surprised I have not read about it more on here. Perhaps people think it's normal especially if they owned from new or low miles. It's just mine only started doing it after the recent works EGR/Turbo. 

Apprciate your response @numskull

Car went in yesterday for its oil change service today. Observation confirmed the presence of the noise. Told to keep an eye on it by them. Based on the info on this thread, I will just have to learn to ignore it. 

 

One thing sprang to mind was I started filing with Shell Vpower since the work, so that's a couple of tank fulls. So perhaps the high Cetane and cleaning stuff is having an impact?

 

Will revert to the normal fuel at Shell and see how it goes. 

 

I am tempted to put some fuel system cleaner in though.

 

Thanks to all contributors on my thread again 

Not just injector rattle ?

Edited 21 July, 20178 yr by dervdave
.

24 minutes ago, dervdave said:

Not just injector rattle ?

Indi said keep an eye or maybe they mean ear out. 

Could be a number of things. 

1 normal like people here say

2 injectors

3 tappets/lifters 

 

Worth trying some new BG 245 (244s successor) and /or a can of Oxicat in a full tank of Shell V-Power to clean out fuel system.

3 hours ago, dervdave said:

Not just injector rattle ?

 

Errrr, do they... rattle that is?

Hell yes diesel injectors rattle to varying degrees, some by their  design etc and others because of issues such as poor spray patterns.

 

On 21/07/2017 at 21:46, dervdave said:

Hell yes diesel injectors rattle to varying degrees, some by their  design etc and others because of issues such as poor spray patterns.

 

Just CR diesels or all, as I've never had this noise eminate from our PD.

Edited 23 July, 20178 yr by numskull
Spelling

11 hours ago, numskull said:

Just CR diesels or all, as I've never had this noise eminate from our PD.

 

To be honest neither have I from any diesel I`ve had to my recollection other than my new Toyota Verso.

Funnily enough the first time I heard it was from a mates Verso.

It sounds very like a petrol motor pinking and is most prominent from a cold engine under load.

I suspect because the CR are at such high pressures they`re more susceptible.

On 7/19/2017 at 22:03, numskull said:

I know that noise very well, and I was told by the Skoda technician that the noise the CR system under load. Our CR170 does it some days and not others and it can be much worse than your recording. I'd describe it a bit like the old pre-ignition sound I used to get on my Mirafiori Sport when accelerating and was really hot and the mixture was too rich. 

I'm away at the moment and I have Renault Captur DCi rental car (which is a gutless piece of #~% btw!) and it's continually making that exact noise when I accelerate. The Renault Kaptur DCi (also %#<&) I had here last month made the same noise too, as did the Megane GT DCi (which was very quick.... but awful quality) I had in April and the truly awful in every conceivable way, Renault Fluence (seriously?) I had before that also made it. 

 

 

Numskull's right...

I too know it very well after having a 2001 Astra diesel that used to sound as though the bottom end was falling out when the cold engine was first started and revved up.

 

My CR170 also has the same noise under the same (variable) conditions. I hardly notice it now.

I believe its down to pre-injection to increase cylinder pressures for better (cleaner) combustion under engine warm up scenarios. 

 

Exact pre-injection timing and quantity (and therefore noise) variable due to different engine temp, air temp, throttle position and load.

 

A 'bit' of info here...

Search 

 

Analysis of noise emitted from diesel engines by S Narayan

 

 

10 hours ago, simannjo said:

 

Numskull's right...

I too know it very well after having a 2001 Astra diesel that used to sound as though the bottom end was falling out when the cold engine was first started and revved up.

 

My CR170 also has the same noise under the same (variable) conditions. I hardly notice it now.

I believe its down to pre-injection to increase cylinder pressures for better (cleaner) combustion under engine warm up scenarios. 

 

Exact pre-injection timing and quantity (and therefore noise) variable due to different engine temp, air temp, throttle position and load.

 

A 'bit' of info here...

Search 

 

Analysis of noise emitted from diesel engines by S Narayan

 

 

@simannjo I preferred the explanation you gave and it's another reassurance. That paper by S Narayan went over my head. 

The noise lets down an otherwise quiet and refined engine. Even for a diesel, remember I came from a PD engine. 

My CR170 becomes nearly undriveable during really cold weather until the engine warms up, I hear the metallic rattling sound. I believe I have a faulty injector, after a Terraclean the engine ran normally even in sub zero temperatures. I am now investigating injector servicing specialists.

I have a 2015 Superb ii 140TDi DSG and I get a noisy click from cold too. Car runs fine otherwise and sounds normal after 10 mins. Have attached a video if it helps anyone...strangely easier to hear from beside the car. Did think a duff injector myself...

Hello,

I'd like to understand why this topic ends without having a solution published. Are the issues resolved by all of you and if so, what was the solution?

Since a while now I experience the same issue as described here. Two reliable sources of mine confirmed independently, the rattling noise is likely to be cause by clogged up dirt on the injectors. So first step they advised is adding a double amount of injector cleaner in the diesel tank, run it (almost) empty and repeat this for a second time if necessary.

In case this. Second step: remove injectors (remember their location) and have them ultrasonically cleaned. Refit them with new seals, 'fire plates' and stretch bolts.

Not sure what to do when second step is giving the desired result, possibly need to find a diesel specialist.

Just resolved the issue, changed my injectors, with OBDeleven I adapted the injectors and primed the fuel pump twice with the Transfer Fuel Pump (FP) test