Is it possible to do a coolant bypass for my throttle body on a 98 z24 2.4L twincam. Also if possible is there a way to do it so i can easily un-bypass it for the cold Canadian winter?
your TB does not have coolant running through it.
it does however have an EGR system, i can pretty much guarantee that is what your thinking is a coolant system.
you can take out the entire EGR system if you want though, GM makes a delete plate that bolts onto the head, its $11 at any gm dealership. you will also need to get a plate for the intake manifold, ive never had to worry about this so i dont know what to do here, maybe possibly find one off a 2000-2002 2.4 intake manifold that does not have the EGR.
z yaaaa wrote:your TB does not have coolant running through it.
it does however have an EGR system, i can pretty much guarantee that is what your thinking is a coolant system.
you can take out the entire EGR system if you want though, GM makes a delete plate that bolts onto the head, its $11 at any gm dealership. you will also need to get a plate for the intake manifold, ive never had to worry about this so i dont know what to do here, maybe possibly find one off a 2000-2002 2.4 intake manifold that does not have the EGR.
No, he is probably thinking the coolant system. You probably already know but it's mainly the imports and some domestics that have coolant running through the throttle body to keep the valve from freezing shut during the winter and you can bypass it and maybe pick up a couple more ponies.

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wow i fail. sorry.
only ways i could think of to do such a thing would be to either find a TB that has the coolant ability and will work on an ld9 (if there is such a thing) or possibly rig up a line system in an obx TB spacer or something along those lines.
one thing i dont get, the way i understand it the factory does the TB coolant setup to warm up the TB during the winter so it doesnt frost up etc, why would you want to UN-DO the coolant setup in the winter? and if you have a reason for that, why would you want to do the coolant in the summer?
my 94 camaro had coolant running through the tb till I bypassed it cavi doesn't have any
z28guy(KGM BEOTCH)
z yaaaa wrote:wow i fail. sorry. 
only ways i could think of to do such a thing would be to either find a TB that has the coolant ability and will work on an ld9 (if there is such a thing) or possibly rig up a line system in an obx TB spacer or something along those lines.
one thing i dont get, the way i understand it the factory does the TB coolant setup to warm up the TB during the winter so it doesnt frost up etc, why would you want to UN-DO the coolant setup in the winter? and if you have a reason for that, why would you want to do the coolant in the summer?
I thought my car had the coolant system already, i wanted to bypass it for the summer.
Joel Steward wrote:z yaaaa wrote:wow i fail. sorry. 
only ways i could think of to do such a thing would be to either find a TB that has the coolant ability and will work on an ld9 (if there is such a thing) or possibly rig up a line system in an obx TB spacer or something along those lines.
one thing i dont get, the way i understand it the factory does the TB coolant setup to warm up the TB during the winter so it doesnt frost up etc, why would you want to UN-DO the coolant setup in the winter? and if you have a reason for that, why would you want to do the coolant in the summer?
I thought my car had the coolant system already, i wanted to bypass it for the summer.
It does not. No 3rd gen cavalier has coolant running throgh the throttle body.
z yaaaa wrote:wow i fail. sorry. 
only ways i could think of to do such a thing would be to either find a TB that has the coolant ability and will work on an ld9 (if there is such a thing) or possibly rig up a line system in an obx TB spacer or something along those lines.
one thing i dont get, the way i understand it the factory does the TB coolant setup to warm up the TB during the winter so it doesnt frost up etc, why would you want to UN-DO the coolant setup in the winter? and if you have a reason for that, why would you want to do the coolant in the summer?
Most people do it as a summer only mod.

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not sure if the 3400 does but i know the 3800 does have it i think i will be blocking it
JBO since July 30, 2001
Z yaaaa- Coolant that has picked up heat through it's circuit is run around your throttle body, which heats it up and contributes to heat soak in the incoming air. That's why it is bypassed in the summer and why it stops things from freezing in the winter.
I think you've got it backwards. Bypass coolant system in summer to keep things cooler. Reconnect in winter to heat things up.
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My Miata Had this, Very simple to Eliminate, Just disconect the feed and return hoses from the TB, then use a MM Push connector to run them together. Retardedly simple.
Adam Kappheim wrote:Z yaaaa- Coolant that has picked up heat through it's circuit is run around your throttle body, which heats it up and contributes to heat soak in the incoming air. That's why it is bypassed in the summer and why it stops things from freezing in the winter.
I think you've got it backwards. Bypass coolant system in summer to keep things cooler. Reconnect in winter to heat things up.
Let me further elaborate. There have been no definitive tests that prove it heats up the incoming air! Keep in mind the air is in the throttle body for just a split second, even less under WOT. Also keep in mind that the throttle body is aluminum and is bolted to an aluminum in take manifold on most cars which is bolted to an aluminum head. What do we know about aluminum...IT TRANFERS HEAT VERY WELL. So the heat from you head tranfers to your manifold then to your throttle body. Now before some one makes the argument that "our cars have plastic intake manifolds" I am well aware of this. It is possible that in some cases in the when the engine is under extreme heat that the coolant might actually cool the tb.
Plastic intake manifolds have an advantage over aluminum because they are A cheaper to make and B don't get as hot as aluminum. Also you will notice on most cars with plastic manifolds do not use tb coolant passages. IE third gen jbodys. and vice versa aluminum manifold and tb passages IE Ford Probe GT
Our cars use the IAC to help control idle which is what the coolant is there for.
Here is a good link to some info on it.
http://www.evotuners.net/forums/f55/throttle-body-coolant-lines-1708/
Edited 1 time(s). Last edited Friday, August 15, 2008 8:53 AM

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Adam Kappheim wrote:Z yaaaa- Coolant that has picked up heat through it's circuit is run around your throttle body, which heats it up and contributes to heat soak in the incoming air. That's why it is bypassed in the summer and why it stops things from freezing in the winter.
LOL i had it wrong the first time, then the second time i had it right, then the third time i got backwards again.
basically, in a nutshell... i first thought (the third time) this guy wanted to know HOW to hook up a coolant system for the SUMMER, which i then thought wtf why would you want it during the summer. but i missed the fact he wanted it bypassed for the summer.
Wade Jarvis wrote:Adam Kappheim wrote:Z yaaaa- Coolant that has picked up heat through it's circuit is run around your throttle body, which heats it up and contributes to heat soak in the incoming air. That's why it is bypassed in the summer and why it stops things from freezing in the winter.
I think you've got it backwards. Bypass coolant system in summer to keep things cooler. Reconnect in winter to heat things up.
Let me further elaborate. There have been no definitive tests that prove it heats up the incoming air! Keep in mind the air is in the throttle body for just a split second, even less under WOT. Also keep in mind that the throttle body is aluminum and is bolted to an aluminum in take manifold on most cars which is bolted to an aluminum head. What do we know about aluminum...IT TRANFERS HEAT VERY WELL. So the heat from you head tranfers to your manifold then to your throttle body. Now before some one makes the argument that "our cars have plastic intake manifolds" I am well aware of this. It is possible that in some cases in the when the engine is under extreme heat that the coolant might actually cool the tb.
Plastic intake manifolds have an advantage over aluminum because they are A cheaper to make and B don't get as hot as aluminum. Also you will notice on most cars with plastic manifolds do not use tb coolant passages. IE third gen jbodys. and vice versa aluminum manifold and tb passages IE Ford Probe GT
Our cars use the IAC to help control idle which is what the coolant is there for.
Here is a good link to some info on it.
http://www.evotuners.net/forums/f55/throttle-body-coolant-lines-1708/
good explnation. coolant is not meant to cool, it is meant to transfer heat. if the coolant is warmer than what it is running through, it would be more than likely that the coolant would transfer heat to it. such would be the case in alot of heated throttle bodies.
i just helped a friend of mine with an 08 SI do this, among other things.
we replaced the upper rad hose with one that was slightly longer and more flexible. the stock one was rubbing on his intake, transferring heat to the intake tube and creating a rub mark on the stock tube that over time could have caused a problem.
we put a spacers on his throttle body. now im a believer that this are good for nothing but a spot to tap nos, but in his case with the gaskets that came with the spacer it spots the transfer of heat from the aluminum intake manifold to the throttle body.
before once the car was at operating temps you couldnt even touch the throttle body and the intake was very warm. the throttle body and intake run much cooler now.
and i for one like my plastic intake manifold. alot of friends made fun that it was plastic and i should get an aluminum one... i still cant figure out why i would want one.
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Chazz with the Asian(SpyWiz) wrote:My Miata Had this, Very simple to Eliminate, Just disconect the feed and return hoses from the TB, then use a MM Push connector to run them together. Retardedly simple.
GM its in the casting you have to change to a different gasket
JBO since July 30, 2001