Coolant bypass on M50 throttle body

[ktteoh]

where can i find info how to do this ? my e34 is in malaysia and i guess i don't need this.

[winfred]

i just connect the hoses together after i trim a little off of them to keep it clean

[Rory525]

where can i find info how to do this ? my e34 is in malaysia and i guess i don't need this.

Why bother taking it off? What you going to gain?

[winfred]

cooler air, not having that crappy plastic thermostat thing in the airbox breaking and blowing all of the coolent out, not having to unbolt that crappy thermostat thing when you remove the airbox, and not burning yourself on the throttle body while working on a hot motor


Why bother taking it off? What you going to gain?

[emw525E34]

But then, the aircond can be blowing real chilly air on cold mornings, then you might want to think twice as the only recourse is to wind down the windows. also rainy afternoons after the hot sun will fog, the windscreen. How do you defog without heat ?

[winfred]

this circuit has nothing to do with the cooling/heating of the car, just the air intake


But then, the aircond can be blowing real chilly air on cold mornings, then you might want to think twice as the only recourse is to wind down the windows. also rainy afternoons after the hot sun will fog, the windscreen. How do you defog without heat ?

[Jon K]

this circuit has nothing to do with the cooling/heating of the car, just the air intake

Winfred - whats the likely hood of the TB freezing? I live in PA, where it's cold. I have been meaning to do this, but people always say blah blah freeze the TB etc etc.

[Jon K]

Heres a pic of how to do this:

http://img133.imageshack.us/img133/4009/customcai09a0je.gif

http://img279.imageshack.us/img279/6936/customcai09c0bp.gif

[Paul in NZ]

why not like this

http://www.bimmer.info/forum/vbpicgallery.php?do=big&p=74.jpg

[Jon K]

because that stupid thermostat sensor is still there. unless you really want that thing hanging out... most of us with cold air intakes remove that sensor from stock airbox and its just sitting in the enginebay looking ugly.

[Anton CH.]

Is that thermostat sensor used for anything? I thought cars with MAFs don't need to take temp. readings.

[Jon K]

Huh? That thermostate opens the passageway for coolant to entire the throttle body. so, when temp in the airbox is cold, that thermostat is open, it never fully opens or fully closes. MAF cars take temp readings, there's a bosch intake air temp sensor on the underside of manifold... all cars need them for timing/spark/fuel.

[winfred]

i doubt it would ice up, i suspect it's more a cold running emissions thing, ambiant engine compartment heat would more then deal with any problem if it exists


Winfred - whats the likely hood of the TB freezing? I live in PA, where it's cold. I have been meaning to do this, but people always say blah blah freeze the TB etc etc.

[Bill R.]

only takes the right combination of humidity, cold and velocity of air traveling through the throttle plate.... Its no fun when it happens to you either, typically it will happen when your cruising on the highway with the throttle open to one position for an extended period of time, then you go to back off and the engine doesn't slow down, you tap the gas thinking its just stuck or binding somewhere, and it enough ice has formed on the throttle plate , when you open it further it sticks in that position and the car attempts to speed up, your first reaction is to push the clutch in or put it int neutral which then proceeds to try and overrev the engine , banging up against the rev limiter in neutral is always fun.. so you finally get it shut down and coast to a stop, where the engine heat rapidly melts the ice on the throttle body and your asking yourself wtf caused this to happen....
Some cars are more prone to this than others and under the right weather conditions it can happen.





i doubt it would ice up, i suspect it's more a cold running emissions thing, ambiant engine compartment heat would more then deal with any problem if it exists

[winfred]

i don't live in the great white north so i've not needed to deal with that particular affliction

[Jon K]

only takes the right combination of humidity, cold and velocity of air traveling through the throttle plate.... Its no fun when it happens to you either, typically it will happen when your cruising on the highway with the throttle open to one position for an extended period of time, then you go to back off and the engine doesn't slow down, you tap the gas thinking its just stuck or binding somewhere, and it enough ice has formed on the throttle plate , when you open it further it sticks in that position and the car attempts to speed up, your first reaction is to push the clutch in or put it int neutral which then proceeds to try and overrev the engine , banging up against the rev limiter in neutral is always fun.. so you finally get it shut down and coast to a stop, where the engine heat rapidly melts the ice on the throttle body and your asking yourself wtf caused this to happen....
Some cars are more prone to this than others and under the right weather conditions it can happen.

Heh mine is post supercharger so I don't worry about the cruising, more concerned about initial start ups

[ktteoh]

Heres a pic of how to do this:

http://img133.imageshack.us/img133/4009/customcai09a0je.gif

http://img279.imageshack.us/img279/6936/customcai09c0bp.gif

jon k, your diagrams helps a lot. just one question: what is the best material to use for the coupler pipe - aluminium, steel, stainless steel, iron etc.

i mean what is best in terms of minimizing corrosion within the engine considering that the m50 head is aluminium and the block is iron ?

thank you so much and merry xmas to you all.

[Andrea K]

jon k, your diagrams helps a lot. just one question: what is the best material to use for the coupler pipe - aluminium, steel, stainless steel, iron etc.

i mean what is best in terms of minimizing corrosion within the engine considering that the m50 head is aluminium and the block is iron ?

thank you so much and merry xmas to you all.


A brass coupler for plumbing should do it.

[ktteoh]

would adding a 3rd. metal (brass) speeds up the corrosion with all the different metals in contact with the coolant ?

so again what would be the best material for the coupler pipe ?

[Jon K]

um, all i know is that brass is used univerally for this retrofit and no one has had corrosion issues....