DaleB

Just so you know... if you have bad or suspected bad vacuum lines, the hard plastic ones that seem to crack and break easily, there's an easy and cheap replacement. I've been using 4mm OD / 2mm ID PTFE tubing for mine. It's commonly used for filament feeds on 3D printers, so it's readily available from Amazon as well as many other sources. It's an easy direct replacement for the original tubing, and it's PTFE -- so very tolerant of high underhood temperatures, it will probably outlast your car, you, and everyone you know. I've replaced all of my air injection vacuum lines with it, as well as a broken waste gate line. That one has been in place for over a year now and is still in perfect condition.

I also found some 3mm ID silicone vacuum hose on Amazon. It's a good snug slip fit onto the PTFE or original hose, and again is silicone is very tolerant of high temperatures. If you have cracked or split sections of black rubber tubing, this stuff will likely be a good replacement.

vettebk

Great information, Dale. I am going to order some PTFE tubing and re-do my lines.

DaleB

Well, this seems to have maybe fixed the P0410 error I had been getting. I won't know for sure until I've done a couple more drive cycles. I'm not entirely sure of the state of the air pump, but so far, so good. The next time I've got the intercoolers loose, I'll replace more of the old plastic tubing. I also want to get the silicone tubing run down to the turbo bypass valves. I figure at nearly 15 years old that original rubber tubing doesn't owe me anything any more, and I'd rather replace it now than wait for it to split.

Of course it also means that I fixed an intake vacuum leak that I didn't know I had. That might explain the engine's sudden return to idling so smoothly that you can't tell it's running. THAT had been bugging me for quite some time. As near as I can tell, that vacuum line must have broken back in 2019. I probably cracked it replacing the coil pack on the right side. With PTFE tubing I'll never need to worry about that again.

vettebk

Great to hear that V12 is running smooth. When mine is idling, you cannot feel the engine running at all. No vibration, no shake. I have seen guys balance a quarter on a running engine.

DaleB

Yeah, mine was like that too. For a little while. Then we started with the misfires, and the this, and the that, and the parts replacement, and the leaky turbo coolant line, and ...

If it's actually to the point where I can drive it again with confidence that I won't need the OBD scanner, laptop, and AAA card whenever I drive it, I will indeed be a happy guy. I am cautiously optimistic right now. I took it out last night and it was as close to perfect as could be expected. I'll do the ride height calibration and replace the trans solenoids this weekend,a nd hopefully that will keep the old girl happy for a while.

Minh

I think this 4mm OD / 2mm ID PTFE tubing can also be used for Airmatic as well.

DaleB

I believe you're right. I read that Airmatic uses the same size tubing. It wouldn't surprise me; it's a common size for pneumatic applications.