PSA: throttle body butterfly valve freezing open
 

This is just an observation I made Saturday night last weekend. Almost forgot about it.

The night of the day I installed the phenolic spacers, I took to the highway and gunned it. Temps are in the 20s and remember I have the tb coolant bypassed.

Under this particular situation and environment, under speeds not going to be mentioned, though perhaps slightly over the local limit of 70, freezing of the tb b valve does in fact occur.

Speed itself is not necessarily important here but revolutions of the engine as air flow increases with rpms and not relative ground speed per se.

What I noticed upon letting off the throttle was a much slower than anticipated/usual winding down accompanied by a whine as if a certain gear is selected at high rpm and not upshifted.

So moral to the story is if you have the tb coolant bypass and you live in an area with a similar climate and expect to be revving either purposely or accidentally (ice will do that) you might want to re-pass the tb coolant through for the duration of the winter :)

On another note, since then with dropping temperatures to the 10s, cruising at low speed has not been affected by this phenomena. (:

you should not have the TB bypass with the phenolic spacers... it is pointless just hook up the tb coolant lines again

Tom

Hi Guys,

What are "phenolic spacers" and where do they go?
Thanks

They are a set of three thick spacers/gaskets made from a material that is poor at conducting heat. The spacers go between the intake manifold and the cylinder heads to insulate the intake manifold so that it does not get so hot. There is also a spacer that goes between the throttle body and the intake manifold. The throttle body is heated by the engine coolant so that's why a spacer is used there. Check out this website:

http://www.outlawengineering.com/

Yeah but it's kinda stuck. I need to cut some new hose all around anyways so I'm going to do it all at once.


Observation 2: Last night with lots of open throttle nothing happened. No freezing. Under 10* all night. o_0 Weird.