Vacuum leak coming from dipstick - normal AOS integrity?
#1
Rennlist Member
Thread Starter
Vacuum leak coming from dipstick - normal AOS integrity?
I rigged up a PVC fitting to pressurize my intake system from the AFM up, and found a leak from the top of the dipstick - it's loud enough to hear from the cabin. When I push down hard on it, it stops temporarily. When I pull the dipstick out slightly, air whooshes out.
Obviously this needs attention, but does my AOS also need to be addressed? I'm not sure if this is normal or not. I have no oil or milkshake in my J-boot or throttle body, so I've always assumed the two seals were good.
Thanks for all pointers/clarification!
(oh, and if anyone has a known-good dipstick they wouldn't mind selling, PM me)
Obviously this needs attention, but does my AOS also need to be addressed? I'm not sure if this is normal or not. I have no oil or milkshake in my J-boot or throttle body, so I've always assumed the two seals were good.
Thanks for all pointers/clarification!
(oh, and if anyone has a known-good dipstick they wouldn't mind selling, PM me)
#3
Rennlist Member
Thread Starter
I intend to re-seal the AOS when I'm doing intake manifold gaskets and TB reseal (this weekend) plus a million other WYIT things.
On my car, the only rubber seal for the dipstick that I can see is the one right under the gripping ring:
...which looks like it is a little worn down.
On my car, the only rubber seal for the dipstick that I can see is the one right under the gripping ring:
...which looks like it is a little worn down.
#5
Burning Brakes
There are no seals on the early cars' dipstick tubes. I don't know if that means that it is okay if they leak, but I went ahead and bought a replacement for $20 on ebay. As far as I can tell they are all compatible at least up through '87. I bought one from a turbo myself, then ordered the o-ring for it. Went on with no trouble. You basically need the top two hits from this search http://www.autoatlanta.com/Porsche-9...Tube-srch.html
As you can see in the picture, the dipstick tube has a lip an inch or two from the bottom that the o-ring can sit against. Our cars just have a smooth tube so an o-ring won't stay in place.
As you can see in the picture, the dipstick tube has a lip an inch or two from the bottom that the o-ring can sit against. Our cars just have a smooth tube so an o-ring won't stay in place.
#6
Rennlist Member
Thread Starter
Thanks! I'd love to skip the $50 price tag though
Also, I have an update which may or may not matter. I ran the engine and pulled the dipstick, and the idle changed very slightly - almost imperceivable. When I revved the engine (which usually creates a leaky whine) it still made the noise, despite the dipstick being out
Starting to wonder what the problem really is. I have lackluster acceleration, and a known leak at the dipstick, that somehow isn't really affected if the dipstick is even in or not.
Also, I have an update which may or may not matter. I ran the engine and pulled the dipstick, and the idle changed very slightly - almost imperceivable. When I revved the engine (which usually creates a leaky whine) it still made the noise, despite the dipstick being out
Starting to wonder what the problem really is. I have lackluster acceleration, and a known leak at the dipstick, that somehow isn't really affected if the dipstick is even in or not.
#7
Burning Brakes
I only spent $20 for mine on ebay. You could try gooping some ATV at the bottom of the dipstick tube just to see if that makes a difference. It doesn't surprise me that pulling the dipstick out didn't matter, you already have a big leak, you just made it bigger.
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#8
Proprietoristicly Refined
Rennlist Member
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I rigged up a PVC fitting to pressurize my intake system from the AFM up, and found a leak from the top of the dipstick - it's loud enough to hear from the cabin. When I push down hard on it, it stops temporarily. When I pull the dipstick out slightly, air whooshes out.
http://www.arnnworx.com/catalog/inde...949680607ce769
J_AZ