odonnell

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)

william_b_noble

the o-ring on the dipstick and on the bottom of the tube are supposed to be common failure points.

odonnell

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.

John_AZ

On my '87 924s there is an O-ring at the bottom of the dipstick tube to oil pan.

konakat

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.

odonnell

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.

konakat

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.

John_AZ

Since you are searching for common leaks, you should rebuild your TB throttle body. The throttle body shaft seals that pivot the butterfly are usually dried out.

http://www.arnnworx.com/catalog/inde...949680607ce769

J_AZ

odonnell

Already got it, it's happening later today!

I'm gonna get a rubber stopper to plug the dipstick hole and see what happens.