is it the gasket that seperates the upper and lower halves of the intake manifold?

You have a gasket on each side of the TB.

One to the intake manifold and one to the plastic intake plenum. The one to the intake plenum is a bad design but there are "fixes" posted.

The intake plenum gasket makes a seal between the plenum and the throttle body. It's a roughly oval shaped thick rubber gasket that slips over the throttle body. The throttle body gasket is a thin plastic gasket that makes the seal between the throttle body and the intake manifold. The intake manifold has gaskets between its upper and lower half and the cylinder heads.

If it's the green one from Audi it's a paper gasket with a wax-like sealant on it. Very very similar to milk-carton paper fibre tho half the thickness.

It'll easily tear and reveal it's layered paper construction. Also an old one will delaminte itelf upon removal. A single-ply plastic cannot delaminate. And plastic would soften/distort under heat and mounting torque.

Ya got a nice thing going with your A/B sensor setup tho ;-)

Yeah, I'm taking about the less than 1 mm thin/thick green gasket. Same material as the valley pan gasket. And yes, I just tore up the old one I still have, and it seems there's a fibrous paperlike substance between two layers of what I believe to be a very hard and slick synthetic material that must have some pretty good heat-resistent properties, although, when I held a flame to it, the material melted and bubbled up like burning "plastic."

What's your opinion on the power source for my little meter? Will 14.5 V fry the meter that's rated 5V-12 V?

and made-do with a few hand-made from milk cartons. It's an old racer's trick. Worked great and insulated the throttle body from heat even better. No need for heat resistance in that area as the TB never sees much over 150F and operates when cruising nearer 90F. It gets hotter when you turn the car off after running for awhile then sitting when heat from other areas migrates or radiates into it... when it can't cool itself via internal air flow.

Top of the intake manifold runs at about 70F on a hot day even when racing. Let it sit for 15 minutes and it's over twice that temp. Any time any part of the induction system is taking in air it's always running much much cooler than you'd think. It only gets hot after turning the car off and letting it sit when it soaks up heat due to migratory and radiant transmission.

Since Auto Speed did that article I'd trust that your meter will be fine wih 14.5 volts. They work on the same voltages we do in Australia and those guys are VERY good at what they do. I'd look for it to have more affect on longevity than any immediate failure but at the price you could replace 5 of them to my one. If you have to replace them once every couple of years it's no big deal. Routine maintenance.

"Mad COW Racing Team" :D

I figured the meter would be alright. I've never actually fried any electronic equipment by exceeding voltage a little. And you're right, longevity isn't that much of a concern with a relatively low price. And it will last longer than the car anyway, I'm afraid.

intact as a hedge against those taking flames to the gasket surface confirming if it's milk "carton" or the more familiar polypropylene gallon milk containers ;-)

PS; Ever hear of "polyperse/polymerase" waxes? Thats the plastic-like sealing substance on those gaskets. Under a pre-determined heat range and pressure it's designed to flow and permeate the absorbent material it's applied to making it an ideal gasket sealing material that will conform to minor surface scratches and remain resiliant thru-out its life.

A paraffin-enzyme something? Sorry, I'm not a biochemist. Sounds like an interesting material. I'm surprised a synthetic wax gasket won't melt under the valley pan cover. Or does it?

the paper fibres. Some does manage to eek out beynd the edges of the gasket material and is lost. But the balance is retained by pressure of the bolts holding the gasket mating surfaces together. Once it migrates/permeates into the fibre very little is compromised as it can be applied in such controlled methods that it's layer thickness is purpose-controlled to soak into and be absorbed by the paper layers it's designed to seal. Any extra is quickly melted and drips/drops away or migrates onto a nearby surface.

It can be modified to flow at many different temperatures and within a very narrow or wide range. Within that temp range it's very long-lasting. Lower temps and it'll never permeate or be absorbed by the gasket it was designed to seal. Higher temps and it will fail rapidly. Under direct flame it will melt, flow, sizzle, bubble, combust them turn to ash. The speed at which that happens is based on the temp range any particular mixture of it was designed to work in, ie fast-to-slow would happen based upon cooler-to-hotter temp mixtures. It's seldom used in any applications exceeding 400-450F with most applications being in the 70F-300F.

It's also a great mold-release agent in casting urethane and some silicone molds which are room-to-low temp casting elastomers. And it's a decent lubricant for low-temp plastic reciprocating/sliding assemblies.

I'm into casting urethane, epoxy, and polyester resins (It's just a hobby). In what form can I buy polyperse wax as mold release? As a powder, or as an aerosol?

where several other uses of it are referenced. I'd try the Google route for finding where or how it's offered for sale. In gasket making it's applied with rubber rollers/platens to gasket material surfaces before individual die-cutting under heat & pressure so I would presume at least for that application it's in liquid form.

You might also search polymerase wax as it too is mentioned as an ingredient of the coating compound along with polyperse wax.

I just did a further search of the Thomas Register for waxes and plastics and while there's a gazillion listings there's nothing further on polyperse/polymerase that I'm able to find. But I'm working out of a 4 year old TR set as I don't know anyone who can afford the complete Thomas Registry hardcover edition new every year.