Gents
Car in question a 01 TT..six speed all stock.
In the morning on cold start up after the engine has ran for about a minute I hear a loud metallic click from the right side of the engine. The sound is most likely coming from the bottom of the engine. Maybe its a switch going bad? I change my oil every 2500-3000 miles. I use Mobil 1 5w40 turbo diesel.

Thought I'd try and figure this out on my own before I head the the shop. Any help would be appreciated.

Markski,
I still owe you a call. Haven't decided on which way I'm going with the car.

 

May be it is related to the air pump which is located on the right forward top of the engine. Can you hear this pump starting at every cold start for about five minutes?

 

I don't hear it at all. The only noises coming from my engine is the loud click in cold start and the normal cold start rattle.
Thanks for the help.

 

If you cannot hear the pump working may be the clicking noise come from a failed pump….Just for your information, the pump looks like this (first picture) on the engine and within the system in the parts cat (second picture). There are some used for sale on Ebay. It can be replaced with the engine in place….This pump got a maxi fuse with is located on the relay carrier #2 which is behind the rear passenger seat not far from the ECU….

 

Wow, you've been a great help!
When I start the car tomorrow I'll put a stethoscope on the pump and listen.
Thanks!


I'm going to check it for noise right now.

 

Good idea but this pump can be loud! Be careful ;-)

 

might be the exhaust expanding...

 

Is it just a single click, or does it click in time with the revs?

When my motor is cold I can hear a tick-tick-tick-tick-tick for a little bit when I come to a stop at a red light or something.

 

Just a single click. Sounds like a light hammer strike on metal.
Going to fire the car in a bit and get back.

 

Fired up the car this morning and no click sound.

Will report back tomorrow morning.

Thx!

 

a suck valve... usually goes away after a minute... more pronounced when car has not been driven for a while... it should be ok

 

ya I'd still bet on the exhaust system expanding and causing the noise...

 

I start the car tomorrow I'll put a stethoscope on the pump and listen.

 

It clicked this morning...took longer this time. About 2 minutes. Combing from under the engine right rear.

Markski, what is a suck valve? Where is it? Thx!!

 

I think he maybe meant "stuck" valve.

There's a thread on the first page about cleaning the air pump with seafoam. Give that a shot.