Throttle body coolant bypass Q

[Payback45]

I have been looking into the TB bypass and it seems pretty easy. I was wondering what the pros and cons of doing it are. has anyone done it? Also, does it matter if you have a IAT sensor or not?

[rougeben83]

I have been looking into the TB bypass and it seems pretty easy. I was wondering what the pros and cons of doing it are. has anyone done it? Also, does it matter if you have a IAT sensor or not?

No it shouldn't matter, the only negative that is cited is that the TB plate could stick in really, really cold weather.

I think I'll try it out during a Detroit winter, see how 20degree weather will do to it...

[Payback45]

I guess i don't understand quite how it all works. I know that there is two hoses going into the TB. I think one has coolant in it. I am not sure what the other one does. I am still learning about all this stuff. When you say stick what do you mean?

[Plays_with_Toys]

They're both coolant. It goes in and immediately goes back out. Basically, when the car is warmed up (at which point the engineers assume you are driving), if you are in very cold weather the aircharge moving across the throttle plate could freeze the plate open/closed. The coolant line goes through and warms up the throttle body to avoid that. I undid the line on my car and had no problems over winter.

[Payback45]

OK I understand now. So being that I am in Maryland and it tends to get a bit cold and being that it is getting colder here now, it might be a god idea to wait on this? Say until spring?

[caoutback]

Ok, I myself have done the TB Bypass mod on my 98 LOB and have to say it was a good mod to do. The line going into and out of the TB are where the coolant goes to keep the TB "warm". Disconnecting them from the TB and connecting them together keeps the coolant from "free flowing" into the engine bay. The TB "sticking" means being "stuck", either open or closed or in between, for a second or two I assume. From the research I did, unless you live where it is Butt F'n Freezing (-40+ w/o wind chill) you have nothing to be worried about, and if you do worry, it takes a couple seconds to reconnect the TB coolant lines together :wink: . Biggest PITA about the whole ordeal is getting to the coolant lines on the TB, due to space constraints. Would definitely recommend doing the mod though.

[Payback45]

That is good to know about the cold. I will definitely try it and see if I see anything.

[Lemanschamp]

anybody mind telling me why this is worth doing? What benefits are there to be had be doing it?

[Reason]

anybody mind telling me why this is worth doing? What benefits are there to be had be doing it?

The lack of the coolant running through the TB won't heat up the air coming in. It just keeps temps down. I did this to my Accord and my friend did it to his 02 maxima and both went through New England winters.

[caoutback]

^^ Also makes throttle response a little crisper :cool: .

[Payback45]

So far it all sounds good.

[Sarra]

I did this to my Legacy. I ended up fuxxoring up a TB gasket in the process, but it was only $4.50 for a new one at the dealership of all places.

IMO it was worth it.

[Reason]

I did this to my Legacy. I ended up fuxxoring up a TB gasket in the process, but it was only $4.50 for a new one at the dealership of all places.

IMO it was worth it.

How did you do that?

[Sarra]

I did this to my Legacy. I ended up fuxxoring up a TB gasket in the process, but it was only $4.50 for a new one at the dealership of all places.

IMO it was worth it.

How did you do that?

The coolant hoses on my TB were cracking and hard. I had to pull the entire TB to get the hoses off, and in doing so, I ripped the gasket.

[Payback45]

that sucks

[Payback45]

I just did the TB bypass. I must not know enough about cars but I would think that you would want the coolant to keep the TB cool. right? why would you want to divert it

[Reason]

I just did the TB bypass. I must not know enough about cars but I would think that you would want the coolant to keep the TB cool. right? why would you want to divert it

In this case the coolant warms up the TB not cool it.

[Payback45]

gottcha

[rougeben83]

gottcha

It's all relative...the coolant is taking heat away from your hot engine, but it's still way hotter than ambient temperature.

As a reference, most thermostats on the radiator turn on at 160-180F