Scary noise on cold start

[soundman98]

Originally Posted by JohnH

as a professional wrench, there are at least 5 normal issues that make this kind of noise. Its definitely a relevant thing to want to listen to it.

For example, is it a lifter not pumping up quickly? Or an exhaust manifold leak? Or a heat shield? Or an item stuck in the belt that flung itself out after a bit? All completely different diagnosis and prognosis. All to Tatatatatatata

could also be an annoying passenger, a passing truck applying their jake brake, or full-auto gunfire.

[humfrz]

Originally Posted by JohnH

as a professional wrench, there are at least 5 normal issues that make this kind of noise. Its definitely a relevant thing to want to listen to it.

For example, is it a lifter not pumping up quickly? Or an exhaust manifold leak? Or a heat shield? Or an item stuck in the belt that flung itself out after a bit? All completely different diagnosis and prognosis. All to Tatatatatatata

As a non-professional wrench, I understand.

I was "jest ah messen wich" ol Ultramaroon -

[radroach]

I've had tapping on startup once, it was the day after my car had been picked up J02 valve spring recall (3 years ago) and the fuel in the tank had been sitting for a month. It was also the middle of July in a 100+*F. I think it was a fueling issue for one reason or another but given it was right after the recall service, can't throw that out.

[Youx]

Hello again guys.

After recording each start for ~10 days, it finally happened again (after leaving it outside for a day and a half), and I was able to capture it :

It starts at around 15s and is quite loud (before that there is the sound of rain). No sure how to describe it, kinda metallic vibration/creaking?

[Yoshoobaroo]

That sounds like metal on metal. First thing I’d do is check the oil pressure on idle.

[JD001]

Originally Posted by humfrz

What part of « ta-ta-ta-ta-ta-ta-ta »,, don't you understand?

Should have bought a VW.. more da-da-da-da......

[JD001]

And then for the computer nerds on the forum:

Excuse the quality, it is Microsoft after all...

[Ultramaroon]

Originally Posted by Youx

Hello again guys.

After recording each start for ~10 days, it finally happened again (after leaving it outside for a day and a half), and I was able to capture it :

I am certain that it's not engine mechanical. Other than that, I could make some wild guesses. It does sound like a metallic creak.

[Youx]

Thanks for the feedback. That would be quite a relief ��

Where would you look at first? I was thinking loud like that it could come from somewhere along the exhaust line, like something loose or a catalytic converter starting to die? (I know from experience catalytic converters can make a metallic rattle when they start to break, although 80k km seems a bit early). Bottom inspection first?

I’ll keep in mind the oil pressure check too, but for now I don’t have the equipment…

[blsfrs]

Can you shoot another video looking under the hood (bonnet). Maybe look specifically at the belt tensioner. Also is the sound coming more from one side of the engine or the other.

[BigTuna]

My first thought was exhaust heat shield rattling or touching part of the frame.

[Youx]

Originally Posted by blsfrs

Can you shoot another video looking under the hood (bonnet). Maybe look specifically at the belt tensioner. Also is the sound coming more from one side of the engine or the other.

I’d say from the driver seat, it felt like it came more from the passenger side, but it’s hard to tell as it lasted only a few seconds.

I’ll get the car back in 2 weeks, so I’ll do another video then (and maybe get someone to start it while I film/listen from outside).

I should also have access to a pit then, so I’ll look at the visible exhaust parts.

Thanks!

[Youx]

Noise with hood open :

https://youtube.com/shorts/hiH5tLVjzGo

[Ultramaroon]

Originally Posted by Youx

Noise with hood open :

https://youtube.com/shorts/hiH5tLVjzGo

It's definitely some sort of rattle outside of the engine. I don't think it's the AC compressor itself but notice that the rattle stops as soon as the compressor quits running. This is most likely because the engine quits laboring to drive it.

It's an odd one! Maybe a loose engine support. It's loud!