Water Lines to and from the Throttle Body
 

I'm curious to find out why the two coolant lines enter and exit the throttle body. One small line comes in from the oil filter base and the second line goes to the thermostat housing. Both lines are located just at the base of the throttle body. What are they for?

Thanks in advance,
Roy

to prevent frosting in winter timez.

for cold winter months, it helps to stop the throttle body from freezing. I have a hardtime believing it is required, but its possible I guess.

Thanks Brain and Joe,
I never would have quessed living here in Calif.

Roy

A speed shop has told me to remove them if I never drive the car in cold weather to drop my temps at the track. I haven't had the Balls to do it.

i mean. i havent had them installed for almost 6 years now.

What's the coldest weather you drive your Miata in Scott? Maybe, I'll man up.

I've started it in 18°f before.

https://www.miataforumz.com/attachme...ine=1333565563


coldest i honestly drive it in? probably 32-40°F.

OK, I'm going to man up then. Mine never sees snow and the R1Rs don't like it under 40 degrees anyway.

If you remove them don't you lose the cooling capability at the oil filter? Not sure how much that really helps the oil temp though.

Roy

i never said remove them from your oil/water cooler.

but, there's honestly no good reason to remove them from the TB.

its a straight through from the oil cooler to the TB, then from the TB to the mixing at the front.

all you need is a coupler to join the two and then just seal off the two nipples at the TB.

I never really removed mine...which is odd considering those things are the two ------- biggest pains in the asses. Especially if you want to take your intake manifold out.

Coupler? Can't you just loop one of the two lines? It's times like this I wish I would get off my ass and put more lights in the garage so I can work at night.

This is really the only good reason! For the short length of the throttle body, any heat that air passing through might collect would be negligible at best.

It would have been nice to remove my throttle body completely when I pulled the top half of the manifold! The Miata is only for summer use for me (damned road salt!) so I won't reap any benefit from a heated TB. Hmm...

no, then you'd effectively remove the flow through the lines. and they are important for allowing the coolant to flow through the block when the thermostat is closed.

fwiw, the coolant only really flows through the idle valve itself, and the coolant should be around 180° which is more or less the same temperature the inside of your engine bay will reach. There's going to be inmeasureable differences in "performance" with or without. Nearly every car in world has coolant running through the idle valve/TB.

nearly every car but One Brains. :) I guess I'll remain on my ass.