Soo, correct me if I'm wrong here, but wouldn't a system that's intentionally designed to HEAT the throttle body also cause a direct increase in intake air temperature and further decrease air density / combustion efficiency?

I was reading up on the gasket replacement for the heater plate, since I'm going through and replacing some of the stupid/cheap items on the DII, but I'm really thinking I'd rather just bypass this thing. It gets up over 100 here in the summer, and the winters aren't too bad (temp-wise) soo, no arctic expeditions or anything for this rover!

Has anyone plugged in a scan tool and measured IAT before/after the heater plate bypass?

 

IMO You could bypass this as long as the temp stays above ~~40 degrees, it's there to prevent throttle plate freezing......not likely that you'll get any performance gain though.

 

I by-passed mine 5 years ago and now, living in Colorado with some -0 cold starts, I have never had a freeze problem.

 

Icing is mostly a concern during periods of extended idling and the amount of heat it will add to the intake air is minuscule.

It isn't expensive or difficult to fix, and if done correctly is much less likely to leak again in the future.

 

I would add that the air temp and fuel temp sensors are before the heater, so it is factored into the calculations by the computer.

 

Bypass that piece of garbage!! I did mine a while back and I will never have to mess with it again.

 

You drive a under powered 4500lbs brick, it aint going to be fast no matter what you do.
You will not notice any power gain by by-passing your throttle body heater.

The t-body heater works with engine coolant, so it does not work when the engine is cold, it does no good in dry climates or the rain forest.
Where it is needed is in humid cold climates, like Chicago, Milwalkee, Grand Rapids MI, Bangor ME...any place where the temps get below 35*F and there is lots of moisture in the air.
When the engine idles the heat builds up under the hood and you wont get ice build up.
When you are driving the air going into the engine is moisture laden and extremly cold, think of the wind chill on a 30*F day with a 60mph wind.
So the actual temp of the air going into the engine is probabaly at or below freezing.
The ECU takes the temp of the incoming air at the air filter box not the t-body.
So it uses that reading to help adjust the air/fuel mixture (it also uses the O2's, TPS, engine temp, rpm, road speed, engine load, trans gear if you have a electronic trans as well as other inputs)

Ever been driving down the expressway and have the fronts of your outside mirrors ice over?
Your t-body will do the exact same thing with no heater.
So why should you care?
Because when it ices over the butterfly valve can freeze in the position it is in, tap the brakes to turn the cruise off and you wont start slowing down, thats why it is there.

 

Oh that's lame! you're right. So there isn't much point then I suppose.


BUT hypothetically people, it really is just pumping heat into your intake air. It seems like a simple engineering work-around that was just kinda "tossed in" there for liability reasons - gotta be a better way.

Considering the lengths manufacturers go through to reduce intake air temps (elaborate duct routing, special thermal-resistant plastics, heat shields, etc) it just struck me odd that they'd PUT heat into the air stream, which can't be reduced/turned off (and is only needed .0005% of the time for most of us!)

Oh well, if it's after the IAT sensor it won't change much anyways (but I DO wonder if the software adds a "set" temp increase to IAT after the coolant reaches operating temperature to account for the heater).

 

Well you will find that almost all cars have a t-body heater.
I bet your Ford even has one.