NordicSeven

When turning off my warm 12A engine after a drive, there is kind of white steam coming out from the air cleaner air intake port. When opening the air cleaner box, one can see that the steam is coming from the large pipe connected from the air cleaner to the cover of the exhaust manifold, not from the carburator ports.
This "smoking" can last few minutes at least. The steam does not smell, and it is not smoke as such - it is more like warm air, but looks rather visible especially when having now almost freezing temperatures. There is no smoke or steam coming out from the exhaust pipes after turning off the engine.

Is this steam normal, or is there something wrong? The exhaust system is rather hot, but I guess this is normal for RX7?! But at least this is somewhat embarrassing, people may thing the car is burning when the steam / smoke is coming under the hood in a parking place!

Denny

If you mean the "hose" made out of a corragated paper material, then it's only the "warm air intake." In the front "snorkel" opening of the air cleaner is a "butterfly" plate. When the engine is cold this plate shuts off cold air from coming into the carb. This causes the carb to get "warm" air from the manifold hose, which is air heated by the exhaust manifold. Once the engine warms up the "heat senitive" spring in the top of the air cleaner cover looses its tension, and the butterfly plate opens up to fresh outside air...

As for "steam/smoke".....Something is getting onto the exhaust manifold and being heated into steam/smoke. Water moisture, oil, coolant, dead mouse?......Paint some flames on it? He,He...

Let us know what you decide, Finlander....

Best to you, and a tip of the Stetson,
Denny, from the 'ol corncrib...

Jeff20B

iTrader: (13)

It could be those O rings between the intake manifold and the rotor housings. One or both could be leaking and dripping onto the exhaust manifold under the heat shield and going unnoticed.

Does it smell like rad juice?

NordicSeven

Thanks,
Leaking intake manifold seal was one of the main guesses for me as well, but I can not smell anti freeze and I have not noticed that I had been loosing any rad. liquid either.
But what has happened is that those exhaust manifold shieds (and their insulation) went rather wet when I removed the intake during the engine rebuilt process - I wonder how long it takes for their insulation to get fully dry?! I have driven the car just a few times after I fixed the engine - perhaps the steam will disappear eventually?!

Anyway, I'll remove the shieds temporarily and try to monitor if there is any leakage.