Grinding/Scraping noise when setting off in morning / after being stationary

[pontiff]

Well I think I am down to the last noise that I have to sort out at the moment (touch wood)... this one is also peculiar.

Okay... in the morning when I set off I 'feel' this intermittent grinding/scraping almost rotational noise for a few kms. It happens from cold, and it also happens to a lesser extent if the car has been sitting for a little while.. For example when I go to the shops for lunch after getting to the office at 8:30.

It goes away after you drive for a a few kms and as I say its intermittent in its duration / occurrence, but will happen every day, if that makes any sense.

I have had a look at the drive shafts, there are no torn boots or leaking grease, thinking that would be the cause. I am yet to check the rear, but I am going to my VW mechanic friend tomorrow to put it on the hoist and see if I can spot anything out of the ordinary.

The part that is throwing me is what could be causing this noise in that it stops after a few kms but comes back every time you get in after its been sitting? I was thinking brakes grabbing but its not the sort of sound you would get from brake pads dragging or similar.

I thought perhaps the lowering of the suspension has damaged something but I had a look at the fronts last night, there is nothing rubbing, the swaybar links look good, nothing torn there etc, all bolts are tight. The driveshafts look good as I say in that no torn boots, i didn't remove them when doing the struts and they sit fairly level as i thought maybe they were 'cockeyed' since the car is lowered, but they're pretty good.

Could it be something transmission related perhaps? (god I hope not)

Has anyone had anything similar?

[Tigga1]

Yes, i have something similar...
I have recently had a CAI fitted, and that's when i started noticing it...specifically in the mornings after startup...
in fact, it can be so loud from inside the car, that I'm worried someone will say: "hey, what's wrong with your car?"
funny thing, the noise is usually gone by the end of the driveway...
it sounds a bit like a grinding, intake, spooling up...not much of a mechanic, but it definitely sounds odd...
BTW, has not affected performance, economy or anytyhing else that i am aware of...

Wondering whether the removal of original intake box has lessened the sound deadening of something in the intake path, and that it was always there but just not noticeable with normal intake.

gavs, did you notice any sounds with your intake?

cheers

[tigger73]

Yes I think depending on the weather conditions this will stay on for longer/shorter time. Intake does make a raspy noise on start-up for a short while.

Not sure if this is the sound you're referring to but it may be temperature related "feature".

[gavs]

The car will run in an over-fuel mode to get things warm and working, this is only for the first few minutes when starting from cold. Yes, there are more wooshes and whistles because I think that the throttle body opens right up etc. what pontiff is describing however, is different. His TSI has the stock air box, I know because we found out what his annoying 'pock pock' sound was, the transmission mount under the air box.

[wai]

It could be brake pads and or discs that have developed a light film of rust. I have had it happen on two previous cars. I learned to trail brake for a few metres to remove that rust and the noise would stop until I left it overnight again.

[VeeDub77]

The car will run in an over-fuel mode to get things warm and working, this is only for the first few minutes when starting from cold. Yes, there are more wooshes and whistles because I think that the throttle body opens right up etc.

Good idea is to let the engine and turbo warm up before taking off.. Once started I always wait until I see the rpms drop before applying any throttle.. something I made a habit off due to owning previous turbo cars...

[pontiff]

It could be brake pads and or discs that have developed a light film of rust. I have had it happen on two previous cars. I learned to trail brake for a few metres to remove that rust and the noise would stop until I left it overnight again.

Yeah I had a look, they seem pretty good, but its bit more 'severe' than just surface rust on the brakes I think, it feels more 'substantial'

[nomadx38]

Yep when the car idles high to warm up I let if finish (most of the time). The odd times that I don't I get very weird throttle response when i take off slowly. it will say rev to 3k rpm under 10% throttle and when the high idle times out (o2 sensors warm up) i will slow down as the 10% throttle only equals 2k. Sort of hard to explain but in all very normal and nothing to worry about.

Also if you put pressure on the brake it changes the tone of the exhaust for the warmup, god knows why...

[TraderTalk]

I am very happy to have stumbled over your post, as my Tiguan makes exactly the same noise.

The noise occurs for the first 1 to 2 km and is much worse on cold mornings. It often doesn't make a noise on hot days.

It sounds like a metallic/rubbing noise coming fron onder the front axel when I go over bumps on the road.

Did you get to the bottom of the problem??

[pontiff]

in my particular car it went away when i raised the suspension (as i had kw v1's at the time) so the thought process was that it was putting added strain on the driveshafts as the geometry of how they were sitting had changed, but why for the first few kms only???? anyones guess unfortunately.

is your car lowered?