Throttle Body Coolant lines

[redlinealley]

What is the purpose of the TB coolant lines? Can they be deleted?

15505083247326621490336978682902.jpg

[me77]

These lines are there to avoid icing of the throttle plate in really cold climates.

[BimmerBreaker]

I've bypassed them on 2 of my cars, will bypass on the third when I pull that intake manifold

I also live in Arizona keep in mind... but I did a lot of research and even people in very cold climates don't seem to have issues bypassing those lines

[rf900rkw]

Carb / Throttle icing doesn't happen in "really cold" climates. It takes extreme humidity, which isn't there in sub-zero weather (or Arizona). The typical danger point is 35-45F, but I've had carbs ice on my bikes as high as 50F. Ambient temp has nothing on the sudden temp drop across a closed throttle plate. The one thing that is required is near 100% humidity.. That and a temp drop of +50 to -30 in like half an inch is what causes the issue.

[Vintage42]

On the 4-cyl 1.9, the flange between the TB and the intake manifold has coolant lines, but the heated flange No. 12 is below the TB and would seem to pre-heat the mixture rather than to de-ice the throttle plate. Is not the fuel injected into the manifold well below the throttle and so could not ice the throttle?
http://www.realoem.com/bmw/enUS/show...diagId=11_1569
https://www.ecstuning.com/b-genuine-...e/11611247752/

[BimmerBreaker]

Carb / Throttle icing doesn't happen in "really cold" climates. It takes extreme humidity, which isn't there in sub-zero weather (or Arizona). The typical danger point is 35-45F, but I've had carbs ice on my bikes as high as 50F. Ambient temp has nothing on the sudden temp drop across a closed throttle plate. The one thing that is required is near 100% humidity.. That and a temp drop of +50 to -30 in like half an inch is what causes the issue.

Interesting, that explains why people in cold climates but low humidity don't have the issue either.

Is there any reason to leave the lines attached in climates where icing is not a concern?

[redlinealley]

Thanks guys.... Considering I just installed the M50 intake swap. I'll do the delete next time I'm in there.

[Vintage42]

Carb / Throttle icing doesn't happen in "really cold" climates. It takes extreme humidity, which isn't there in sub-zero weather (or Arizona). The typical danger point is 35-45F, but I've had carbs ice on my bikes as high as 50F. Ambient temp has nothing on the sudden temp drop across a closed throttle plate. The one thing that is required is near 100% humidity....

We don't have carbs, and the fuel is injected into the manifold below the throttle.
So how does icing occur for a Z3?
If the coolant lines are for de-icing, where does the moisture come from?
Or are the lines for warming the intake air? My two early 1970s BMW 2002s had intake air heaters going from their exhaust manifolds up to the big air cleaners.

[Remotion]

I deleted from mine last summer. The engine side is closed with oilpan bolt and clothes drying rack thingie, either use a U hat pipe like this: https://www.do88.fi/fi/artiklar/sili...0mm-musta.html
or leave a short piece of hose and put a 10mm bolt at the end of it and ofcourse tighten it with hose clamps.
It is for warming intake air which is stupid for summer season cars.

[rf900rkw]

Interesting. The coupe, M52TU and M54, doesn't have a throttle heater. At least in this market. Do you have a different engine? Or maybe they did a different intake/throttle for the Tundra edition?

And before someone jumps in comparing apples and oranges. The electric throttles don't need the heater as much because the conditions that cause icing are avoided in software.