EdPorsche996

So unfortunately it is the AOS. looks like it's cracked. Changing it isn't going to be fun.

DBJoe996

Been there done that, and it is a royal PITA job. Until I drop the engine and check I will never know if that first manifold bolt is in right. In fact, I told myself if I ever have to do that again, I will either pay someone to do it (that I trust to do the job right) or drop the engine and do every maintenance item I can think of. If you search you'll find some good write ups on AOS replacement, but standby, this one will challenge you in unbelievable ways, your mechanical abilities and patience, and your tool box.

kromdom

this would be me

Slakker

I've heard dropping the tranny makes the AOS a much simpler job then going in through the rear. But if you go the normal route, loosen the manifold bolts before wrestling with the plenums.

kromdom

particularly true for TIPs

Robeguyl

OK, time for a daft question, but I will ask it anyway. I have a 997.1 2005, 137k miles with exactly the same issue, one of the small protruding arms from the top of the AOS connecting to the coolant pipe has a hairline crack and its leaking. I live in Texas and whilst it is my only daily driver its rarely cold. Why not use a connector to connect the in and out coolant pipes and bypass the whole dam AOS? Will this cause a problem for daily running?
I don't mind engine out and doing the job if I can time it with a new clutch (done a 60k) or other work, but a significant bill just for this seems like a waste.
What do you you all think?

PS: I can reach the AOS from under neither the car so although it wont be easy I think I can get to both pipes with a little struggle.

Cheers

Argeo

This blows, sorry to hear about the situation. I have zero to offer unfortunately.

DBJoe996

Yes, you can connect the coolant hoses together to bypass the AOS. I would do it back by the air filter box so you don't have to contort yourself under the car. The supply hose is next to the alternator and the return line is over by the secondary air injection hose on the 3 way coolant hose coupler. Given that you are in Texas this really should not cause any problems. The AOS coolant hoses provide coolant to the AOS to help condense the oil mist when it is cold out.

Robeguyl

Thanks Joe...will give it a go. Guy