The pipe is the lower heater pipe going through the wall between the engine end the passenger compartment.

There is nothing wrong with the pipe by itself - the rubber grommet that seals the pipe to the wall is gone - water from rain is leaking in and flooding the drivers side (very badly).

The access is very limited - the heater (plenum) is connected with a screw to the pipe - any attempts to seal the area with plastic (black) sealants failed.

As one could guess - access from the dashboard is not attractive at all.

My question is - have you heard or used some sealant that is in (semi) liquid form - and could get around the pipe poured - that gets cured by the air and forms a protective barrier?

Or any suggestions how to prevent the water entering the car due to the broken grommet?

 

Why don't you just go to the dealer and get a new grommet? I suspect that this grommet is split so it can get around the pipe so you can probably install it without any disassembly. The trick may be access.

If you really do not care what it looks like and there is not much motion try using that expandable foam stuff from Home Depot that you use to seal around window and door frames.

 

It happens that taking off some panels under the dashboard revealed the entry point of the pipe- tremendous relieve.

The grommet is made by the white rubber that has short life span.

Once there is an access - will check with dealers (thanks for the suggestion) or use some silicone sealant.

(the PU foam for windows is hygroscopic)

 

You might consider checking McMaster-Carr. They have a lot of grommet sizes available and that might be simpler than using RTV. Best of luck.