Intake manifold Coolant Hose

Chris6 said:

It heats up something so when cold starts are easy, But it also heats up the manifold. Its a hose.

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I think you may be referring to two different items here.

There is the BAC which adjusts the cars idle depending on coolant temperature(cold coolant means high idle and when the engine/coolant warms up the idle lowers to 750rpms or so). On removing the coolant line..Id suggest not to do this. I have had a faulty BAC before and without it functioning properly it seems the ECU figures that the engine is cold all the time and defaults to a high idle setting all of the time(like 2000rpms).

On the 90-92 cars there is a coolant jacket that was added to the throttle body. In cold climates sometimes there can be frosting on the throttle butterflies which can make for a sticky throttle. The coolant jacket was added to warm the plates so this would not happen. This is separate from the coolant that runs to the BAC. Its interesting to note that there are plenty of 88-89s that are in cold climates and without the coolant jacket on the TB but its rare to hear of this phenomena occurring...maybe in the arctic?

Removal of the line is something that owners of other cars that have a similar setup have done. The assumption is that the coolant heats the surrounding area and adds to heat soak of the intake manifold. A cool intake manifold and cool air is always better for that extra bit of power. Its my guess (could be wrong about this) that the intake air is rushing in so fast that there is little heat transfer from the intake manifold anyway, so removal of the line for the coolant jacket isnt worth that much. Something....but not that much.

Gavin

yea thats normal, and yes gavin is very informative!
you might want to click on the little down on the left side of his post to leave some karma for him.
(not enough people use this button)

and Gavin, I agree with all you said, and the little extra heat that would be there from the coolant, is very minimal, vs. all the heat around the manifold in the first place.

I don't think it would do anything with the idle though, as long as the BAC was still there and hooked up. I know yours was idleing high, but i'm sure this was just due to the unit not functioning properly.

Either way, I don't see a gain in removing the line either, unless strictly a 1/4 mile car, that your ''iceing" inbetween runs........