Hi all,
I would like to call on all 996tt owners to stick their heads under the rear bumper/fender and have a look at the exhaust/ turbo. Have a close look at all the nuts to the silencer and turbo and also have a look at your wastgate and actuator rods & actuator and as best as you can the Turbo bearing housings. This is a good idea for your own peace of mind. Your Porsche dealer will not tell you about this form of corrosion and it is not covered in the maintenance schedules.
I have had a look at a 3 year old 997tt and it was not good so don’t think because you have a later 996tt it will be ok.
To put thing right ( your self) if the corrosion is very bad can set you back about £5000/£6000 buying the parts from Porsche ( including Turbos, which I didn't).
I don’t expect you to slag your car off over the net, but be honest, lets see if there are more cars out there apart from mine. All you have to say is you have a problem.
Its not the end of the world, but you do really need to know how bad it could be,
especially if you intend to keep the car like me.
Sorry for the downer, its not meant to be. I would just like to know if I am the only one, which I know is not the case. Its all well and good if the car looks a $1000000 but if underneath look like a Trabant then its time to fix it.
NB Safety notice, I only realised I had a problem when one of my Turbo heat shields spun down the road at 70 mph narrowly avoiding another car. The wastegate had seized shut so I was still pulling good boost the rod had also corroded throught and snapped. The clamp bolt holding the silencer onto the engine creadle normally 8mm was 4mm in diameter ( rusted away). This is just the safty side of things. There was lots more.
Can of worms springs to mind, but as the saying goes you have to break eggs to make an Omelette !
I look forward to hearing from you.
It would be nice to hear from the good cars too, not just the corroded ones.
Frank.

 

Mine has lots of signs of corrosion around the turbos, was a nightmare when i swapped the exhaust, in the future i will be swapping turbos so not to upset.

 

yea nuts behind the cat as well as couple between turbo to manifold were corroded. When removing, one of them just broke apart and couple others stripped. Good thing i had a stripped bolt tool. wastegates and everything else in good condition. it'll be more severe for cars that have salt on the road, located in high humidity and/or near the sea. worth while to have a visual at every oil change.

 

So what all needs to be replaced? Basically - if I'm going to purchase a used one - what should I look for that an owner can prevent this (or fix it)?

(I'm not THAT familiar with your engine, so a list would be very helpful)

 

it's just the bolts that hold the manifold to the turbo and the turbo to the cats. 10 11 or 12mm hex bolts, can't recall. if find corrosion, remove and replace the nut. and make sure to use antiseize and torque correct value. dont want to damage the stud.

 

That doesn't sound too bad at all...

 

Hi,
Here is a list of problems in the order I came across them.

Heat Shields
All, rpt all the exhaust nuts missing ( corrosion)
All Turbo flange nuts almost missing ( looked like a pine cone)
Studs corroded ( not serviceable) all ot them . Honestly all of them.
L/hand waste gate seizure
L/hand waste gate actuator arm corroded and broken.
Exhaust mounting band M8 corroded to 4mm ( very easy to undoo, just broke apart)
Turbo Oil pipes ( see my posting) seized on Turbo and oil Tank and also into the Turbo oil pump housing. Had to replace all the pipes ( 6 in number). That was a nightmare.
Turbo mounting bracket nut almost corroded away ( I would say by about 60%). Both Sides.
Sent turbos to C&R both bearing housing so corroded they broke open when being dismantled.
Both actuators perforated with rust.
One wastegate seized.
Shaft alignment out, due to excessive corrosion of turbine housing.

It goes without saying, I have copper crested all the joints & nuts so far and will continue to once I have the recon ( New) Turbos.

Please do not get too worried, if yours is not this bad then do some maintenance yourself before it does. You Porsche Garage wont do it at a service. If you do keep on top of it you will be ok. If you haven’t, now is the time to have a look and put things right.

Needless to say I am a bit dis-hartend to have to do this to a Porsche.
Seven years of British weather has its toll to pay.lol
Frank

 

Its nice of MadNess to write a reply to my post, however dont be fooled by his answer. If it was that simple I wouldnt be waisting my time writing this would I.

 

Thanks for the detailed list.

 

Your welcome,
How is your's. I hope its ok.
If not I can give you some advice on the removal of the Turbo oil pies. It can be a real pain.
Frank

 

I'm actually in the market for picking one up - used. So I'm going to carefully inspect these parts. But now I know it can be fixed (if it's bad), I'm not going to worry too much.

 

It can be fixed but depending on the extent of the problem it isn't cheep to do. If Porsche had repaired my car it would have cost near £8000.
2 Turbos are £4400. £116/hour soon ads up. They want £3.60 ish per Nut and the same per Stud ( what's that all about). I don't think your Porsche Warranty will help as it doesn't cover corrosion. Well it didn't when I had one.
Its the Turbo side of things that cause the problems. If you can get away with just nuts then brill. Infact I will say it again because its worth thinking about. if its just nuts OK, any more and its a can of worms.

I do live in Scotland so the weather can be , shall we say , changeable.LOL