mytrplseven

I bought 2" PVC fittings from hardware store and drilled and threaded air nipple in and inserted it into the intake boot between the air filter box and the boot. You have to pull the AFM but that's easy and gives you a chance to clean it up. I pressurized it to around 7psi and using soapy water found two vacuum leaks. One was a rubber elbow to the temp sensor under the intake runners and the other one.....well see for yourself. This is an easy, foolproof to find your vacuum leaks.

choinga

...and it gets clean!

I have a turbo, but the TB seal is notorious for leaking...there's a rebuild kit (got mine at Paragon) that takes an hour or so and you're good as new. Nice catch!

mytrplseven

disassembled the Throttle Body today and there's no seals around the throttle shaft!! I don't get it. supposedly my kit will have shaft seals to stop the leaking. Also did a TPS test while it was easy to get at. Got to clean all the hoses and stuff normally hidden by the boot, airbox and AFM. sure hope it starts when I'm done.

mazdaverx7

what on the throttle body is leaking? is it the butterfly's shaft seal?

Cass944

I have used this method before.

Another way of doing it is just getting a small propane torch. Open it up (but don't light it) so that gas is coming out. wave it around the engine bay with the engine running. when the vacuum leak sucks in the propane the rpms will immediately shoot up. its a quick way to find them without making too much of a mess.

mytrplseven

Yes the bubbles were pouring out just below all the throttle controls on top of the TB. When I disassembled the TB there wasn't any kind of seal on the shaft to keep the vacuum contained. The reseal kit I ordered was aware of this and includes a seal to fix this. One thing that did amaze me was that Porsche has needle bearings inside the throttle body for the butterfly shaft instead of bushings. You won't find that on American carbs and probably not on TB's either.

mazdaverx7

awesome! where did you order your TB reseal kit from?

choinga

http://www.paragon-products.com/Thro...aw_944tbrk.htm

Turbo:
http://www.paragon-products.com/Thro...aw_951tbrk.htm

mytrplseven

Ordered the re-seal kit for the TB from Paragon on Friday and it showed up today (Monday). The kit is very explicit and if you follow it to the letter you can't miss. Put the rebuilt TB back in the car and re-pressure tested all the vacuum system. No bubbles! Started it up and it barked and rattled and ran like crap. I was so involved in working over the AFM, TB and vacuum system that I forgot to plug the stupid connector to the AFM back in. This thing really runs like a new car. Wow! Well on to another project.

AKCJ

I have learned that the best spray on soap to find air leaks is 409. You can make your own soapy water for cheaper but 409 really, really works well.

Thanks for posting, very helpful thread.

ZR8ED

The biggest fear of the DIY'er is to fix something only to find you broke two other things while fixing the first. Nice find, who would have suspected a vac leak there, where there are dozens of old vacuum lines all over the place! Makes me want to check to see if I have any minor leaks! (mine is running very well "knock on wood" so I doubt it)

mytrplseven

Actually, in my earlier post I said there were "no" seals on the TB shaft. That actually wasn't the case. They're small and they get hard and ineffective. I didn't have a right-angle scribe to remove them (shown in the re-seal directions) so I used my Dremel to make a sharp point on a 16D nail and bent the sharp end at about 1". That got into the tight space to remove the hardened seals (in pieces) and then reinstalled the new ones with a shortened #2 pencil. Sounds hokey but it works. Secret to success: Follow the directions in the kit exactly....everything.

Hollywood D

Would you be able to hear air escaping from the TB is the leak was bad enough?

mytrplseven

I heard air passing through the manifold somewhere but I'm sure it was going through partially opened valve somewhere. The main thing was using soapy water solution is fool-proof. I didn't put my ear to anything specifically. It's easier to just watch for bubbles. Car just flat scoots now. The seals in the TB were hard and came out in pieces using my home-made scribe.

F18Rep

777...Good idea with the pressure test adapter, I've seen this same idea for the turbo but never tried to find a PVC fitting for the NA. A modified fuel filter will work but its not as good a fit as your PVC adapter.

Its been a long time but if I remember right, when we tried this there a big air leak downstream maybe through the head, did you have the crank/cam at some particular spot?...Bruce