Cayenne Turbo - Odd Noise

[bimjim]

Hello.

This is my first post here, despite being a member for a while. I've always found my answers

by searching (first Boxster, now Cayenne), but I've not had much luck with this one...

My Turbo has started making an odd noise. It's difficult to describe, but it's a bit like a chirping

sound. It only seems to be present when lower down the rev range as I pull away.

It also goes, or is inaudible, once the engine has reached normal

operating temperature.

Any ideas? It's done just over 60k miles.

[mudman2]

Present when idling ?

Present when Rolling in neutral ?

Can you hear it outside ?

Sparrows nests ?

[bimjim]

No.

Not sure.

Yes.

Maybe.

[DanielPrince]

I have had our CTT for a year and only a couple months ago I noticed a "tweeting" from the engine when I pulled away as well. I was told it was the injectors firing...makes sense.

[lnferno]

Does it sound like a dentist drill? If so, sounds like one of the turbos may be on its way out.

[bimjim]

I have had our CTT for a year and only a couple months ago I noticed a "tweeting" from the engine when I pulled away as well. I was told it was the injectors firing...makes sense.

Does it go once everything has warmed up?

Does it sound like a dentist drill? If so, sounds like one of the turbos may be on its way out.

It's probably a bit more subtle than a dentist's drill, depending on your dentist I guess.

My first thought was a turbo. How do they work on these engines? Is there a big one and a small one complimenting each other?

[wvicary]

Inspect the drive shaft centre brng assembly. Spray it with WD-40 and see if the noise goes away.

[bimjim]

Inspect the drive shaft centre brng assembly. Spray it with WD-40 and see if the noise goes away.

I'm not 100% sure what that looks like or where it is, but I'll hunt out some pointers on here.

Thanks.

[wvicary]

The rear drive shaft or carden shaft is a two piece unit supported by a bearing assembly, the grease seal on the brng came become dry and cause a rotational squeak/chirp noise.

[bimjim]

The rear drive shaft or carden shaft is a two piece unit supported by a bearing assembly, the grease seal on the brng came become dry and cause a rotational squeak/chirp noise.

Thanks. I'll take a look tomorrow, the weather's not so good here today.

I did just go for a drive and it was much quieter, perhaps the dampness around has helped. The last time I took it out it was cold and dry, today it's warmer and much wetter.

I'll report back.

[mudman2]

That being said expect a new shaft shortly if its the original one

[bimjim]

I've now got it booked in to be looked at on Thursday. I'll report back with the diagnosis.

Thanks for all your help.

[bimjim]

That being said expect a new shaft shortly if its the original one

Bingo - It's been diagnosed today, and a new shaft has been ordered.

I'll report back next week after it's been installed.

[bimjim]

Just to close this one off - The shaft has now replaced and everything runs as it should.

It seems any warmer/wetter weather helped lubricate the bearing, which reduced the noise. I guess I was lucky to get it replaced before it went completely.

Thanks for all the advice.

[pontypool]

Sorry to open this thread up again but I have got a similar sounding noise from my turbo and I just wanted to see if the sympoms are exactly the same.

I get:

- Chirping noise from front of engine bay somewhere, but hard to pin exact location (but think it is from around turbos)

- Only on start-up idle, disappears once under way

- Stopping after 1/2 a mile and at idle the chirping is still there

- After three or four miles the chirping on idle stops completely.

What am I potentially looking at?