Strange rattle cold start b7 passat 2.0 tdi

DRSEire

Hi. I have a 2012 2.0tdi passat with 80k miles on the clock. Yesterday I noticed on cold start that there was a strange rattle coming from the left side of engine bay. Sounded like a chain rubbing off a metal casing if you get me(sorry for the bad description). The noise was gone after 5 mins. I started it again this morning and I could hear it again although it was not as loud and noise disappeared very quickly. I was wondering if this could be a timing belt? As mentioned 80k miles on the clock. Will send it in to the dealers for diagnostic this coming week but would appreciate the thoughts of others in the know here if possible. Any help much appreciated.
Thank you.

Stoolbend

When you say left do you mean the left as you look in at it from the front?

DRSEire

Stoolbend wrote: »

When you say left do you mean the left as you look in at it from the front?

Hi. Yes sorry I should have been more clear. Left side as I look in from front.

Stoolbend

If it only does it on cold start in the morning you'd want to leave it at the garage overnight so they can hear it in the morning.

DRSEire

Thanks for the info. Would you know if the car is due a timing belt change at 80K miles? It's the 2.0tdi bluemotion.

Toyotafanboi

They are due a belt every 5 years or 210k kms. Unlikely to be the timing belt making a grinding noise unless there is something critically wrong.

DRSEire

Toyotafanboi wrote: »

They are due a belt every 5 years or 210k kms. Unlikely to be the timing belt making a grinding noise unless there is something critically wrong.

Thanks. Would you believe I started it again there now from cold and the noise was not there. Very confusing. Yesterday the noise was awfully loud. First start this morning the noise was there but not half as bad and disappeared very quickly, I didn't drive the car. 4 hours later no noise on start and after short drive the car drives excellent as always. Head scratching stuff.

George Dalton

Timing belts can be noisy on these at cold idle but not really the same type of noise you are describing.

Air con compressor can make a very similar noise to what you describe though. Next time it happens try turning the air con off and on and see if the noise changes. If it does then you know it’s related to the air con.

JohnBoy26

Could be the flywheel

DRSEire

Thanks very much for the replies guys. Will try that next time George thanks. Regarding the flywheel, I had one go before on a car and I don't believe it's anything like that. No clunk when switching off engine and noise was there when clutch pressed/depressed. Also noise was gone after a min or 2. I could be wrong though. Will keep an eye on it. Again much appreciated guys, thanks.

TigerTim

Just sold my Citroen C-Crosser & for the past month I was getting a loud noise from the dual mass flywheel/clutch when cold. Once the engine was warm, the noise was gone. Was only there when clutch was pressed - not there when car just idling.

T.

DRSEire

TigerTim wrote: »

Just sold my Citroen C-Crosser & for the past month I was getting a loud noise from the dual mass flywheel/clutch when cold. Once the engine was warm, the noise was gone. Was only there when clutch was pressed - not there when car just idling.

T.

Thanks Tim
I think George hit the nail on the head and it looks like it could be an ac compressor issue. There is a loss of coolant also with no indication of a leak. Looking at the ac compressor I can see a small stain on it which may indicate a leak. Other components very clean. Also got a strange burning smell from ac at times which I previously thought was just dpf cleaning. I also noticed that the fans ran alot after short journeys around town when engine was switched off. I also put this down to dpf and short journeys but now im thinking this could be all related. George if you read this would this make anymore sense to you? Thanks.

George Dalton

I’d say the smell and fans running are signs of a regen alright.

The A/C compressor won’t be related to the coolant loss either.

But water pumps are a weak point on them and can be noisy when they fail so that’s another possible cause.

DRSEire

George Dalton wrote: »

I’d say the smell and fans running are signs of a regen alright.

The A/C compressor won’t be related to the coolant loss either.

But water pumps are a weak point on them and can be noisy when they fail so that’s another possible cause.

Thanks George.

DRSEire

George Dalton wrote: »

I’d say the smell and fans running are signs of a regen alright.

The A/C compressor won’t be related to the coolant loss either.

But water pumps are a weak point on them and can be noisy when they fail so that’s another possible cause.

Just to update, it turned out to be the water pump. Bang on the money George. Thanks again.