Ok one more quickie - throttle body gasket - wet or dry?

[adam12hicks]

So when I pulled my throttle body heater pieces there were two metal gaskets between the throttle body heater and intake manifold, and it was covered in red rubbery gunk.  When I reassemble my intake and put new gaskets on, should the gaskets get treated with some sort of RTV or other sealant or should they be bolted up dry?

Thanks!
Adam

[Wise Old Dog]

Dry, no RTV on any intake system. It will kill your O2 sensor.

[adam12hicks]

Ok thanks!  I wonder why someone used this red rubbery goodge (that's not a word) on the metal gaskets... so the throttle body to intake manifold is separated by a single dry metal gasket?

Thanks again for the response!

[nicknikolovski]

It could be rubber grease, not sure why its on there.

[tjts1]

Dry, no RTV on any intake system. It will kill your O2 sensor.

Unless you use "O2 sensor safe RTV". I just used RTV on the TB gasket, between the lower and upper halves of the manifold and at the head. No gaskets = no problems.

[Wise Old Dog]

I would be concerned that the silicone would squeeze out internally and create an airflow disturbance. Although it would seal better than the OEM gasket.

[tjts1]

Yes, you have to be very careful in how you apply it. It has to be a very thin layer, evenly spread along the outside edge of the port. You want it to squeeze out toward the outside of the port as much as possible.

[strad]

Those metal gaskets are designed and intended to work without sealant.  They are designed to crush seal at correct torque given clean flat mating surfaces.  

If anyone besides a dealer/good independent shop has worked on your car in the past, chances are they did not know what they were doing.  That would explain the presence of sealant.

[adam12hicks]

Yeah I'm not sure what work was done.  The car has 130k and was a 1 owner.  It still has everything factory in place, but has a new fan clutch.  The throttle body had definitely been removed though I'm not sure why it would have been.  Everything else looks OEM.

Thanks for the advice guys.   Oh and Strad, you say those are crush gaskets, but is it published anywhere how much torque should be applied to the throttle body stud nuts for them to seat properly?   (I said stud nuts... I'm going to tell my wife that's my new name.)

[strad]

I could not find that torque figure quickly in the E36 manual.  I seem to remember finding it though when I did all my vacuum lines.  Pretty sure I torqued those fasteners to 11 ft-lbs.

[adam12hicks]

Excellent thanks for the response!