Kevin

The Defector>> I can think of better things to spend monies on.. Replace your wideband O2's, replace your MAF's.. Buy a set of Caron Fiber 997GT2/GT3RS seats, Fork out $8500 for a new set of 997GT2RS turbochargers. I think that it's premature to do this repair on your engine which might never see the camshaft sleeves failing.

Like I said in the previous post. The coolant fittings are a greater risk at failing>> mainly the oil cooler/heat exchanger.. And BTW, those that "like" to do preventative maintenance

I should start a new thread...

Drain your gearbox fluid..

And front diff..

Repack your CV joints at 55K (they are expensive to replace)...

Replace your Wideband O2 sensors (Genuine Porsche only).. You will feel a difference and save a few buck in fuel..

Guys that track there cars can remove there tranny mounts and fill the webbing voids with High Viscosity Fast Cure Urethane (NAPA part number 4180-Black)

Replace your fuel filter

If you track your car.. I would almost bet that your LSD clutch pack is toast... You can rebuild them vs buying new..

estrellajon

Replace O2 sensors? As in all 4? Pre and Post? Repack CV Joints? As in the inner and outer boot? Does Porsche just sell the boots?

Kevin

I always write (wideband O2's) pre CAT.. The rear O2's don't give us issues until 80 to 100K....

The boot's don't need to be replaced unless torn. You need to buy new metal bands with the proper banding tool.

estrellajon

Thanks for the clarification Kevin. Sorry I did miss the wideband part.

A418t81

I had the camshaft "spin" failure. You can read all about it over on 6speed. It was a very expensive failure as my intake cam sprocket also appeared to be get slightly damaged when it occurred. It slipped relative to the intake cam itself on first engine fire-up after reassembly TWICE. The friction disc was installed and looked fine as well. We ended up replacing the VVT intake sprocket, cam bolt, etc. All fine now, but the price after a couple mods I threw in while the engine was out (BBi slave, torque solutions emgine mounts) was 10 grand and I was without my car for nearly 4 months before it was all sorted out.

I should note, this appears to be an up and coming failure as more cars get more miles. My mechanic has repaired 4-5 in the past year and he's not a big time shop.

saabin

Same here, started as an innocent CEL light.. once I read out the code I knew what it was..

https://rennlist.com/forums/997-turb...aft-story.html

Local dealer (thankfully under CPO) had the engine out twice trying to fix.. 1st time they just replaced the variocam actuator, and I made it about 5 miles driving home before the light came back on..

Engine back out and this time they replaced the cam, cam sprocket, and cam bolt.
Dealer seemed to indicate it was not a common failure that they see, although it's a fairly small dealer..

I did see the invoice "before" the CPO was applied and Kevin was spot on.. about 8.5K

cdk4219

Lots of pinning to fix these engines? Is it lugging/stalling, hitting the rev limiter, or something else making them spin? I can guess the number is lower simply from the drastically lower production numbers of the 997.1 turbo (and the simple fact that they are newer) does this affect tiptronic cars that wont get the lugging or rev limit?

nzskater

That's an interesting question - of the cars that have had the issue, how many have been tip/manual?

bondjockey

I doubt anyone has the answer to that question. Maybe someone can do a poll. There doesn't seem to be any rhyme or reason to the failures though -- manuals, tips, tuned, stock, low mileage, high mileage, all have experienced failures. I asked a tech at a large dealership in Atlanta how many they have seen and he said a grand total of three over the last two years.

The Defector

NICE!!!
Front diff and gearbox, sounds like a plan before this driving season. Fuel filter's a good idea too. Gotta find the drain plugs and filter location. How hard can that be? Car is in the air right now.
Why MAF, is there an upgraded one? What does "wideband" mean, is that different than OE?
The coolant lines I plan on doing this fall....
THANKS again Kevin,
JC

Kevin

A wideband O2 has a greater sensor value range reported to the ECU. PreCat or Ahead of CAT, is the wideband O2... Porsche Part number 997.606.128.02 Do not get aftermarket.. The Bosch aftermarket sensor does not have the correct insulation boot fitted AND is 5 inches short...

MAF's are sensors that degrade over time. I would recommend replacing them with factory Genuine at the 75K or every 10 to 12 years... Do not use a oil air filter, the lifespan gets cut in half due to the oiling of the hotwire filament. Carbon is plated on the wire, and the resistance value are incorrect.

L_perm

Is it really a fact that the spun cam cannot cause catastrophic damage?

Not questioning anyone's knowledge, or trying to start an argument. I just want double clarification because I am a preventive maintenance kind of guy.

Can the cam not spin enough to cause interference? These engines are interference-type aren't they? Or not?

Again, the reason I ask is because I have almost come to the conclusion that if I decide to have my coolant fittings pinned/welded, then I'll just have the cam issue dealt with at the same time.

Thanks,
Louis

P.S. The only "hard" thing about the fuel filter replacement is that you have to have the right tool, correct?

Kevin

LPerm, hear is a simple explanation.. The system is like a old fashion ON/OFF push button dimmer for your dining/family room lights.. The ECU acts like the push button on/ff switch. It will pulse the current to control the solenoid. The solenoid is like a gate valve allowing oil to pass into the variocam module. The hydraulic pressure MOVE the variocam >> Dimmer switch moving from low light to bright..

The cam is moving.. It will NOT change the valve lift action (that is done with the low lift/high lift inlet tappets). The duration is changed.. We have 50 degrees of movement>>the dimmer will go from low light to high/bright in term of cam advance/retard angle..

Are we 100% certain that there are no valve contact.. I have spoken with my piers (more than 50 skilled Porsche techs "factory trained" across the world, and I have yet to hear of valve contact with just the camshaft sleeve slipping..

Now, there are issues with the VARIO CAM module failure AND camshaft gear slippage that WILL produce valve to piston contact. The 997GT3's have had variocam module failures with the fasteners coming loose WHICH will destroy the topend of the engine>>bent valves and piston damage.

The above mentioned FAILURES are rare in the 997TT. AND not related to the camshaft sleeve rotational failure. The camshaft sleeve failure cuts OFF the oil flow from the solenoid to the VARIO CAM module. It's like pushing the round dimmer button OFF.. You can rotate the button all day long with no lights.. The circuit is not working>>no oil is going to the variocam...

L_perm

Thanks for the explanation Kevin. I was under the impression that the cam was spinning relative to the camshaft, hence my concern. Glad you straightened that out for me.

Louis

estrellajon

^^^ great explanation.