996TT Engine Rattle in high gear

[Foie Gras]

As I get to know the Porsche more, I understand more what is 'normal' (e.g. oil consumption) and what is not.

However, one thing that I'm not sure about is a very loud rattle, almost very exaggerated pinking, from the engine when I am in too high a gear and try to accelerate. Typically 30mph in 4th and put your foot down brings it on.

Is this normal?

TIA



FG

[lynchygt3]

hi the 2 i've had have not done this so id get it looked at ! i can put my foot down in 5th at 30 and she will pull nice and strong without any noise !

kev

[Martian O]

Heat shields? Common problem.

[Zip106]

Mine doesn't do it now.
It used to, until I had the heatshields replaced.

[zeb]

Martian O said:

Heat shields? Common problem.

+1

[Foie Gras]

Reading between the lines then....

...I should have a look at the heatshields?

Thanks guys




FG

[Chipchap]

Foie Gras
As the others have said, most likely a rusted heatshield that has broken away and is setting a harmonic vibe.

You will know when a Porsche "pinks, pings or detonates" it sounds just like firecrackers going off. Totally unlike any other car.


A

[996ttalot]

Regardless of the issue (+1 heat shields or exhaust bracket) why are you driving the car with too much load? 5th gear pull from 30mph is unnecessary on the engine.

[996TT_STEVO]

Chipchap said:

Foie Gras
As the others have said, most likely a rusted heatshield that has broken away and is setting a harmonic vibe.

You will know when a Porsche "pinks, pings or detonates" it sounds just like firecrackers going off. Totally unlike any other car.


A

That's true A... reminds me a bit like a machine gun

[Foie Gras]

996ttalot said:

Regardless of the issue (+1 heat shields or exhaust bracket) why are you driving the car with too much load? 5th gear pull from 30mph is unnecessary on the engine.

Because I occasionally get it wrong, main car is an auto.


FG

[zeb]

996ttalot said:

Regardless of the issue (+1 heat shields or exhaust bracket) why are you driving the car with too much load? 5th gear pull from 30mph is unnecessary on the engine.

here endeth the sermon from the pistonheads division of the IAM.....

[dean1057]

If anyones requiring replacement fasteners for the turbo studs, nuts and manifold bolts, I've just made up sets which include the 14 studs, 14 washers, 14 all metal self Locking nuts and 18 manifold bolts these are manufactured from aircraft grade high strength stainless (not your 304(A2) / 316(A4) off the shelf stuff). I've made 6 sets up which I've used one set and sold one other set so i have four sets left but will make some more up. Selling these kits for £150 a set, these really are fit and forget not like the poor quality porsche ones that rot within a few years. Our company is www.tachart.com My email is [e-mail] if you need to contact me.
See below

[Diesel130]

lynchygt3 said:

... i can put my foot down in 5th at 30 and she will pull nice and strong without any noise !

kev

Wow - is yours electric?

[speed8]

dean1057 said:

If anyones requiring replacement fasteners for the turbo studs, nuts and manifold bolts, I've just made up sets which include the 14 studs, 14 washers, 14 all metal self Locking nuts and 18 manifold bolts these are manufactured from aircraft grade high strength stainless (not your 304(A2) / 316(A4) off the shelf stuff). I've made 6 sets up which I've used one set and sold one other set so i have four sets left but will make some more up. Selling these kits for £150 a set, these really are fit and forget not like the poor quality porsche ones that rot within a few years. Our company is www.tachart.com My email is [e-mail] if you need to contact me.

I wish you had posted a couple of weeks ago. I've just had my car in to do all the heat shields, manifold bolts, turbo nuts/studs etc. Basically everything under there.

[masopa]

That's a coincidence, mine has just started doing a similar thing. I took it into the garage about a week ago to have a minor service, MOT and the tyres replaced. Now I get a really off-putting vibration at between 1200 and 1700 rpm (approx). No unusual noises above that rev range, though. I sounds/feels like it's coming from the exhausts or engine and is definitely a vibration-type of noise but is strong enough that you can nearly feel it.

I've been away from home since the service so haven't had a chance to take it back to the garage yet.

Same problem - heatshields??

[EvoSlayer]

Could be the engine mounts are mullered!

[Ed Winchester]

dean1057 said:

If anyones requiring replacement fasteners for the turbo studs, nuts and manifold bolts, I've just made up sets which include the 14 studs, 14 washers, 14 all metal self Locking nuts and 18 manifold bolts these are manufactured from aircraft grade high strength stainless (not your 304(A2) / 316(A4) off the shelf stuff). I've made 6 sets up which I've used one set and sold one other set so i have four sets left but will make some more up. Selling these kits for £150 a set, these really are fit and forget not like the poor quality porsche ones that rot within a few years. Our company is www.tachart.com My email is [e-mail] if you need to contact me.
See below

I was advised to use the genuine, soft Porsche nuts on the turbo studs. These, whilst prone to corrosion are apparently designed to allow for expansion caused by the glowing turbos. After seeing the state of the ones that came off, I'd be happy to hear that stainless studs/bolts are a safe replacement

.

[lynchygt3]

Diesel130 said:

lynchygt3 said:

... i can put my foot down in 5th at 30 and she will pull nice and strong without any noise !

kev

Wow - is yours electric?

of course why is yours not ? Wow -






Ps electric cars don't have gears....... So no 5th to pull silently away from 30 in

[_gez_]

Ed Winchester said:

dean1057 said:

If anyones requiring replacement fasteners for the turbo studs, nuts and manifold bolts, I've just made up sets which include the 14 studs, 14 washers, 14 all metal self Locking nuts and 18 manifold bolts these are manufactured from aircraft grade high strength stainless (not your 304(A2) / 316(A4) off the shelf stuff). I've made 6 sets up which I've used one set and sold one other set so i have four sets left but will make some more up. Selling these kits for £150 a set, these really are fit and forget not like the poor quality porsche ones that rot within a few years. Our company is www.tachart.com My email is [e-mail] if you need to contact me.
See below

I was advised to use the genuine, soft Porsche nuts on the turbo studs. These, whilst prone to corrosion are apparently designed to allow for expansion caused by the glowing turbos. After seeing the state of the ones that came off, I'd be happy to hear that stainless studs/bolts are a safe replacement

.

I'd be more worried about this. Would it be an issue?

http://en.wikipedia.org/wiki/Galvanic_corrosion

[dean1057]

The studs / bolts are made from a magnetic martensitic stainless thats used on maifolds and turbos. The nuts are another softer stainless thats similar hardness to the standard porsche ones. We supply a lot into the Motorsport industry, including formula 2 and rally teams. The formula 2 cars go for a nimonic material but they are in a different league to a road going turbo car. They use Audi turbo motors.
I'm a qualified metallurgist so know a thing about materials. Up to you guys but I know myn are there to last without problems.
Regards
Dean