lexus-is2

Can anyone kindly tell me what is involved in removing the throttle body? i can see the bolts, and the electronic connector and obviously the air intake. what else is connected to the TB that needs to be removed?

Many thanks

lexus-is2

According to lexus tech manuals, to remove and re-install the throttle body apparently the coolant needs to be drained and re-filled afterwards. Is this correct? apparently there are 2 water by-pass hoses to the throttle body.

Also it mentions that i will need to install a new gasket to the intake air surge tank.

Can anyone kindly confirm this? I am assuming since the two hoses that connect to the throttle body are water related that they must be connected to the cooling system and hence opening it will either leak coolant or let air into the system.

Gville350

iTrader: (10)

Curious as to why you are removing the TB to begin with? I would imagine there would be coolant lines passed through or around the TB. Any time you remove a component that uses a gasket, it is best to replace it with a new one.

lexus-is2

I've sourced a cheap used TB as I think something wrong with either my throttle position sensor, idle valve as since I cleaned it and replaced the MAF rpm has got worse. I've got a new gasket to re-seal it but wondering if it would be necessary to actually drain all the coolant as the Lexus tech docs say or if I can simply just quickly swap out the hoses and catch any small leaks with a rag? Seems like a waste of coolant to drain and change just to change the TB

Gville350

iTrader: (10)

You can crimp the lines to avoid water loss, but you are still having air enter the cooling system. I don't know Lexus's recommendation for air evacuation for a cooling system, but I'm sure it's not complicated.