Question

[s3am]

For those of you who have seen the video 'a cautionary tale' below www.pistonheads.tv/clip179

I have been hearing the odd whirring sound coming from the boost gauge, which is clearly audible in the first scene (where I am destroyed by the 993TT)

The noise doesnt seem to be having any effect on performance but it does seem to be related to throttle opening/boost pressure (ie louder noise at larger boost), and it is extremley annoying, esp on trackdays etc when the hammer is constantly down, and from inside the cabin it can almost drown out the engine noise!

Does anyone have any experience of this? Or know what it could be?

Any help most welcome!!

Sam

[obes]

From the gauge itself, or is it a vibration being carrried through the dash ?

[s3am]

The noise seems to be coming from that area, but not precisely from the gauge, its hard to identify exactly where its coming from. I suspect its from behind it. The last mechanic to look at it though it was from the transmission but they couldn't find it... and couldn't fix it!

Sam

[LaurenceFrost]

I'm 99% sure that it's the pressure hose that connects to the back of the gauge (that's what it sounds like in your vid).

Basically there is a pipe (usually rubber) coming from the inlet manifold (throttle side) to the back of the boost gauge. The pressure (or vacum) that is in the manifold is the same in the pipe.

It is this pipe that the gauge gets its information from. It sounds like 1 of 2 things. Either the hose has come away from it's connection at the back of the gauge slightly, or the hose has a slight split in it. The air is leaking out, and this is why you get the noise.

Hope this helps.

[s3am]

Laurence thanks,

Its one of those noises you can't quite put your finger on but that sounds like it. I'm going to the dealer on thurs, so I'll get them to check.

Thanks again,

Sam

>> Edited by s3am on Tuesday 9th November 22:08

[micknall]

Laurence is basically correct: I've had a similar problem on one of our demo cars. It's a rare fault, so if the dealer needs to speak to us we can give him any assistance required.

[s3am]

micknall said:

Laurence is basically correct: I've had a similar problem on one of our demo cars. It's a rare fault, so if the dealer needs to speak to us we can give him any assistance required.

Thanks Simon. It's no surprise then that it had been confusing a few people...

Sam

[LaurenceFrost]

I actually think it sounds pretty good

[s3am]

LaurenceFrost said:

I actually think it sounds pretty good

That's what my dad said, but trust me its more than a little annoying on the long motorway slog.. much nicer to hear the engine undiluted!

Sam

[smuudge]

(where I am destroyed by the 993TT)

Are 993TTs that quick then??

[DanH]

Apparently that one had 500 bhp, and compounding it he fluffed a gear change. Frankly if the Porsche had that much power I'm surprised it wasn't a much bigger gap!

[s3am]

smuudge said:

(where I am destroyed by the 993TT) Are 993TTs that quick then??

See my other post www.pistonheads.com/gassing/topic.asp?t=135522&f=26&h=0

the 993TT is derestrictors www.pistonheads.com/members/showCar.asp?carId=2701

Even if I hadn't fluffed the change I would still have been behind.

Sam

[smuudge]

blimey, im staying well clear

[s3am]

micknall said:

Laurence is basically correct: I've had a similar problem on one of our demo cars. It's a rare fault, so if the dealer needs to speak to us we can give him any assistance required.

Hi Simon,

I finally put the car in to be rectified at Kerridges. But rather than there being a problem with a pipe at the back of the gauge, I was told there had been a leak in the turbo gasket. Do you know if that is correct?

Cheers,

Sam

p.s. Does anyone know how much power I would have been down? I thought I was a little short at Vmax!!!!