bonehead

I don't think this is a guarantee either. Certainly decreases the chances of them backing out, though.

SupraSaiyan

I wanted to do all the preventive maintenance during the winter and only got around to it. Coolant pipe pinning, RS 4.0 clutch, new LWFW, waterpump, thermostat, all new bolts/screws/nuts, a bunch of new engine seals, Cup shifter cables, and finally Dundon damper.

Just spoke to the shop, they verified my cam actuator bolts are perfectly intact and engine will be back in this week.

Never been this excited for spring in a long time.

Tom@TPC Racing

Yes, thread locker can be used. See post # 408 in this thread- https://rennlist.com/forums/997-gt2-...07-gt3-28.html

kyrocks

There are no warning signs and I pick up on everything. My 2010 RS has the cam bolts back out.

kyrocks

Mine backed out about 3 months out of warranty. Porsche covered it with a new $65k engine.
Car was never the same.

bonehead

I almost bought your car 3 years ago. What was it that was never the same?

hf1

Is this the best RL thread that aggregates the preventative solutions to this problem? Which gt3/rs models are susceptible to it? What are the costs of the different preventative solutions? Thx!

bweSteve

Thanks for finding this thread, and posting to it hf1 (I'm pretty sure you are in the market for a RS, so I want to write this here, to ensure clarification....)

I remember reading through this thread about a year ago,... and recall coming away with the assumption that this problem with cam actuator bolts was primarily seen with LWFW and higher probability on the RS cars, not the Dual mass regular GT3's.

Is that a bad assumption?

TIA,
=Steve

Steve2k1116

this is the conclusion i have come to after reading everything i can on this issue.

this off season my car is having a lot done (coolant lines welded, etc) and i have been going back and forth on putting in a LWFW or not while the engine is out and i still havent decided what route to go with these bolts because of it.

Auto_Werks 3.6

The occurrence is certainly less on the DMF cars, but the engines are essentially the same, and a dual mass flywheel is not primarily a harmonic damper. Its job is to damp driveline shock. There's enough evidence that these engines have real harmonic issues that personally I think it's a good idea to have the damper on a base GT3 as well. The financial investment is pretty small and there's no down side. 911 harmonic issues go all the way back to the 6 bolt flywheels that used to lose fasteners in motorsport application. Eventually they made the flywheels 9 bolt attachment, but seems like they didn't address the underlying issues. I will also be checking the actuator bolt torque at a minimum any time the engine comes out for clutch or coolant line service.

bweSteve

excellent feedback Auto_Werks. Thank you for that. I am very close to Michael & Tom over at TPC, so maybe the M7 bolt modification will be something I have them take care of.

.... I guess something could be said for going "too far" in being proactive,... but another question (maybe for Tom) would be,... Can you do both a M7 bolt upgrade AND have it wire tied? (like FLTSPD refers in post #7).
Is that M7 bolt head big enough to drill a pilot hole through? ... or would that weaken the bolt head itself?

Also, Steve2k1116 above,... if you are already planning to spend the time & $$ to have the coolant lines done, and contemplating a LWFW, sounds like you should not let the actuator bolts get in your way to making that decision. If you're already going that far, then having a harmonic dampener installed &/or having the M6 bolts replaced/strengthened / locktite / re-torquing, should be a no-brainer. my .02

=Steve

Steve2k1116

absolutely agree. really the problem is more if i should spend the money for the LWFW and dampener when the LWFW is known to increase harmonics, or just replace my clutch with a dual mass again and be done with it.

my issue is i over analyze everything. most likely will just do everything but i want to be comfortable in my choice.

hf1

So 996.2, 997.1, and 997.2 gt3 (with DMFW) don't have this problem, while 997.1 and 997.2 RS both do? Or is this just a 997.2 RS problem? No shop (most of them Porsche and GT/Cup car specialists) has ever mentioned anything about this issue with my 996 GT3. What "harmonic problems" do these engines have? First time I'm hearing about this.

Again, what are the preventative solutions and how much do they cost? Losing a Mezger engine over smth like this would not be "fun".

bonehead

This thread provides more info

https://rennlist.com/forums/997-gt2-...cking-out.html

Auto_Werks 3.6

http://performancedevelopments.com/p...enginefailure/

Symptoms are subtle... I saw one guy have a cam bolt failure on his RS, and it also had cracked the mount tabs on his alternator when he stripped the engine. That's a definite clue the there's a vibration problem when hard mounted parts are cracking. The 997.2 RS also has a recall on some fasteners in the intake tube that vibrate loose and ruin the engine. Also supposedly not an issue on the base GT3. If I remember correctly there were earlier generations of GT3 that would have the crankshaft pulley loosen up and fall off when a light weight flywheel is installed. It's bee a long time since I looked into that so I don't remember, but I think that was 997.1. You can also search threads on the aircooled cars and see where people had a hard time keeping the old 6 bolt flywheels to stay tight.