DIY: [Throttle Body Coolant Bypass]

Cole Austin · 01-26-04, 06:32 AM

There has been some discussion in this thread about the throttle body coolant bypass.

This is a very simple DYI and almost anybody (within reason) can do it.

Tools:
10mm socket wrench
Philips head screw driver (optional)
Needle nose pliers
Bucket (to catch any coolant that comes out)

*Materials (note: my hoses were dry-rotted so I needed to replace them)
1) About 2 feet of 1/4" high temperature rubber tubing (available at most any hardware store or auto parts store).
-You can buy the pre-formed hose from Acura but the tube at a hardware store is about $0.49 a foot, you can't beat that deal.
2) Hose clamps (Just use the ones that are already located on the original hoses)

Basic procedure summary (further down is the detailed procedure with pictures):
1) Remove the intake
2) Remove the throttle body cable cover
3) Re-route the Idle Air Control (IAC) coolant line to the Throttle Body (TB) coolant out plug
4) Connect the TB "coolant in" and "coolant out" plugs together with 1/4" tubing.
5) Put the throttle body cable cover back on
6) Put the intake back in the car.
7) Start up the car and check for leaks.

If you already have a basic idea of what is going on with this tutorial, you can skip to step 3 of the procedure.

Procedure:
1) Remove the intake.

I have a CAI intake, so for anybody that has a factory intake, removing it is not hard. (Note, I don't know what all is needed to remove the intake from the legends with mas air flow sensors)
-Loosen the hose clamp that connects the intake to the throttle body with the 10mm socket.
-Disconnect the vacuum line and oil line from the intake.
-Remove the filter cover top and disconnect the resonator box (at least I think its a resonator box) from the radiator.
-Now the intake tube should just lift out.

You should see the following:

I'm pretty sure the Idle Air Control (BLUE) coolant line flows from out of the IAC into the base of the Throttle body. From there it heats the TB and flows back out of the TB and back into the engine block (YELLOW). (But its not real important which direction the coolant flows)

2) Remove the throttle body cable cover

3-4) This is the most important part.

Remove the 3 hoses from the bottom of the throttle body:

Coolant is going to come out, but not a lot. Its going to seem like a lot if you have never messed with the cooling system before, but don't worry you won't loose much. Just try to catch most of it in a bucket (to save cleanup time). If necessary check the coolant levels (once finished after you start the car to check for leaks) in the overflow tank and add any necessary coolant.

When removing the hoses, loosen the hose clips with the needle nose pliers. After you loosen the hose clamps, twist the hoses on the plugs with the pliers to un-stick the hoses, then simply remove the hoses.

Connect the IAC coolant line to the lowest plug on the throttle body (the one in the picture with the coolant coming out of it)

Simply connect the remaining two plugs together with a small piece of tube.

*If you buy new hoses, they may be hard to get onto the plugs, Just work with the hoses a little until they go on.

5) Put the throttle body cable cover back on
6) Put the intake back in the car.
7) Start up the car and check for leaks.

Cole Austin · 01-26-04, 06:35 AM

Also, I needed all new hoses because the ones that were originally hooked up to the throttle body were leaking. You can do this DYI with out buying any new hoses. Instead of using a small piece of tube to connect the TB plugs back together, you can just re-route the existing tubes.

This is where my leak was:

Here is the replacement tube:

**Mike Diaz** · 01-27-04, 01:58 AM

Want me to move it to the DIY section? BTW, it's DIY for Do It Yourself. I'll edit the title, but you should edit the pics.

Cole Austin · 01-27-04, 05:48 AM

Yeah, I'll fix that image too

94LegendCoupe · 01-27-04, 06:42 AM

Throttle Body Coolant Bypass

I FINALLY got a damn pic

lDneGeL · 02-13-04, 03:48 AM

what exactly does this do?

Cole Austin · 02-13-04, 05:27 AM

Quote:

Originally posted by lDneGeL
what exactly does this do?

It helps keep the throttle body cooler, by bypassing the coolant (heated by the engine). It just stops hot coolant from running through the throttle body to heat it.

Cooler air = More dence air

More dence air = more power.

**Mike Diaz** · 02-13-04, 06:02 AM

Fix that DYI to DIY and I"ll move it

BuggyWu7 · 02-24-04, 01:13 PM

now i'm looking to do this on my car too, but was wondering if it's safe and reliable for our engines cuz' if it is why didn't the car come out of the dealer like this,will i be risking some reliability by doing this???

USMC-THUG · 03-22-04, 02:57 PM

I would like to know as well

Cole Austin · 03-22-04, 03:09 PM

I have not had any problems yet...

oh and Mike I fixed the image... so you can move it to the DIY section finialy.

coloTypeII · 04-14-04, 07:30 AM

Pics are not working and I'd like to see them

Cole Austin · 04-14-04, 07:39 AM

Quote:

Originally posted by coloTypeII
Pics are not working and I'd like to see them

Whoooops how in the? hold on I'll fix em.

coloTypeII · 04-14-04, 08:31 AM

Thanks cole

Badjack10 · 05-05-04, 03:09 PM

you think this would work on a g1?

01-26-04, 06:32 AM	#1 (permalink)
Cole Austin VIP alllll the way Join Date: Aug 2003 Location: Roanoke, Virginia. Attend School @ VCU in Richmond Posts: 4,587 Car 1: 92 L Rosewood Brown Sedan iTrader: (0)	DYI: [Throttle Body Coolant Bypass] There has been some discussion in this thread about the throttle body coolant bypass. This is a very simple DYI and almost anybody (within reason) can do it. Tools: 10mm socket wrench Philips head screw driver (optional) Needle nose pliers Bucket (to catch any coolant that comes out) Materials (note: my hoses were dry-rotted so I needed to replace them) 1) About 2 feet of 1/4" high temperature rubber tubing (available at most any hardware store or auto parts store). -You can buy the pre-formed hose from Acura but the tube at a hardware store is about $0.49 a foot, you can't beat that deal. 2) Hose clamps (Just use the ones that are already located on the original hoses) Basic procedure summary (further down is the detailed procedure with pictures): 1) Remove the intake 2) Remove the throttle body cable cover 3) Re-route the Idle Air Control (IAC) coolant line to the Throttle Body (TB) coolant out plug 4) Connect the TB "coolant in" and "coolant out" plugs together with 1/4" tubing. 5) Put the throttle body cable cover back on 6) Put the intake back in the car. 7) Start up the car and check for leaks. If you already have a basic idea of what is going on with this tutorial, you can skip to step 3 of the procedure. Procedure: 1) Remove the intake. I have a CAI intake, so for anybody that has a factory intake, removing it is not hard. (Note, I don't know what all is needed to remove the intake from the legends with mas air flow sensors) -Loosen the hose clamp that connects the intake to the throttle body with the 10mm socket. -Disconnect the vacuum line and oil line from the intake. -Remove the filter cover top and disconnect the resonator box (at least I think its a resonator box) from the radiator. -Now the intake tube should just lift out. You should see the following: I'm pretty sure the Idle Air Control (BLUE) coolant line flows from out of the IAC into the base of the Throttle body. From there it heats the TB and flows back out of the TB and back into the engine block (YELLOW). (But its not real important which direction the coolant flows) 2) Remove the throttle body cable cover 3-4) This is the most important part. Remove the 3 hoses from the bottom of the throttle body: Coolant is going to come out, but not a lot. Its going to seem like a lot if you have never messed with the cooling system before, but don't worry you won't loose much. Just try to catch most of it in a bucket (to save cleanup time). If necessary check the coolant levels (once finished after you start the car to check for leaks) in the overflow tank and add any necessary coolant. When removing the hoses, loosen the hose clips with the needle nose pliers. After you loosen the hose clamps, twist the hoses on the plugs with the pliers to un-stick the hoses, then simply remove the hoses. Connect the IAC coolant line to the lowest plug on the throttle body (the one in the picture with the coolant coming out of it) Simply connect the remaining two plugs together with a small piece of tube. If you buy new hoses, they may be hard to get onto the plugs, Just work with the hoses a little until they go on. 5) Put the throttle body cable cover back on 6) Put the intake back in the car. 7) Start up the car and check for leaks. __________________ http://www.directimagehost.com/is.ph...ial-mod-si.jpg Throttle Body Coolant Bypass General F.A.Q. 2nd Generation F.A.Q. People I trust to buy items from: bboarder711 \| legendarysleeper \| Chauffeur First \| SmartJay28 Last edited by Cole Austin : 04-14-04 at 07:45 AM.

01-26-04, 06:35 AM	#2 (permalink)
Cole Austin VIP alllll the way Join Date: Aug 2003 Location: Roanoke, Virginia. Attend School @ VCU in Richmond Posts: 4,587 Car 1: 92 L Rosewood Brown Sedan iTrader: (0)	Also, I needed all new hoses because the ones that were originally hooked up to the throttle body were leaking. You can do this DYI with out buying any new hoses. Instead of using a small piece of tube to connect the TB plugs back together, you can just re-route the existing tubes. This is where my leak was: Here is the replacement tube: __________________ http://www.directimagehost.com/is.ph...ial-mod-si.jpg Throttle Body Coolant Bypass General F.A.Q. 2nd Generation F.A.Q. People I trust to buy items from: bboarder711 \| legendarysleeper \| Chauffeur First \| SmartJay28 Last edited by Cole Austin : 04-14-04 at 07:46 AM.

01-27-04, 01:58 AM	#3 (permalink)
Mike Diaz WHAAAAAH! Join Date: Jan 2002 Location: N Canton, Ohio Posts: 10,983 Car 1: 3.5L 1991 LS Coupe 5 Spd Blk/Blk Car 2: 1994 Civic EG Hatch Car 3: 03 Honda TRX400EX iTrader: (2)	Want me to move it to the DIY section? BTW, it's DIY for Do It Yourself. I'll edit the title, but you should edit the pics. __________________ 2nd Gen FAQ \| Newbie FAQ \| Bleeding Coolant DIY \| Manual Trans Flush DIY 3.5L DIY \| Crank-No Start Diagnosis \| How I built My Legend

01-27-04, 05:48 AM	#4 (permalink)
Cole Austin VIP alllll the way Join Date: Aug 2003 Location: Roanoke, Virginia. Attend School @ VCU in Richmond Posts: 4,587 Car 1: 92 L Rosewood Brown Sedan iTrader: (0)	Yeah, I'll fix that image too __________________ http://www.directimagehost.com/is.ph...ial-mod-si.jpg Throttle Body Coolant Bypass General F.A.Q. 2nd Generation F.A.Q. People I trust to buy items from: bboarder711 \| legendarysleeper \| Chauffeur First \| SmartJay28

02-13-04, 03:48 AM	#6 (permalink)
lDneGeL 1ofAknd Join Date: Jun 2003 Location: san jose,CA Posts: 1,837 Car 1: 92 CGM Legend L sedan iTrader: (0)	what exactly does this do? __________________ http://img43.photobucket.com/albums/...dnegel/sig.jpg

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01-27-04, 06:42 AM	#5 (permalink)
94LegendCoupe Banned Join Date: Nov 2003 Location: Florida Posts: 393 Car 1: 94 Legend Coupe iTrader: (0)	Throttle Body Coolant Bypass I FINALLY got a damn pic

02-13-04, 06:02 AM	#8 (permalink)
Mike Diaz WHAAAAAH! Join Date: Jan 2002 Location: N Canton, Ohio Posts: 10,983 Car 1: 3.5L 1991 LS Coupe 5 Spd Blk/Blk Car 2: 1994 Civic EG Hatch Car 3: 03 Honda TRX400EX iTrader: (2)	Fix that DYI to DIY and I"ll move it __________________ 2nd Gen FAQ \| Newbie FAQ \| Bleeding Coolant DIY \| Manual Trans Flush DIY 3.5L DIY \| Crank-No Start Diagnosis \| How I built My Legend

02-24-04, 01:13 PM	#9 (permalink)
BuggyWu7 RX7-->Legend Join Date: Jun 2003 Location: EnYcEe~ Posts: 346 Car 1: 1994 Type2 6-Speed Coupe iTrader: (0)	Is it safe??? now i'm looking to do this on my car too, but was wondering if it's safe and reliable for our engines cuz' if it is why didn't the car come out of the dealer like this,will i be risking some reliability by doing this???

03-22-04, 02:57 PM	#10 (permalink)
USMC-THUG Registered User Join Date: Mar 2004 Location: Newark, NJ Posts: 30 Car 1: 1992 Acura Legend coupe LS-DkGreen iTrader: (0)	I would like to know as well __________________ <img src="http://mysite.verizon.net/computerthug/Me/4.jpg">

03-22-04, 03:09 PM	#11 (permalink)
Cole Austin VIP alllll the way Join Date: Aug 2003 Location: Roanoke, Virginia. Attend School @ VCU in Richmond Posts: 4,587 Car 1: 92 L Rosewood Brown Sedan iTrader: (0)	I have not had any problems yet... oh and Mike I fixed the image... so you can move it to the DIY section finialy. __________________ http://www.directimagehost.com/is.ph...ial-mod-si.jpg Throttle Body Coolant Bypass General F.A.Q. 2nd Generation F.A.Q. People I trust to buy items from: bboarder711 \| legendarysleeper \| Chauffeur First \| SmartJay28

04-14-04, 07:30 AM	#12 (permalink)
coloTypeII Registered User Join Date: May 2003 Location: Aurora Colorado Posts: 370 Car 1: 1994 Black Type II 6-Speed Coupe iTrader: (0)	Pics are not working and I'd like to see them __________________ http://www.imagestation.com/picture/...0/eef09e67.jpg

04-14-04, 08:31 AM	#14 (permalink)
coloTypeII Registered User Join Date: May 2003 Location: Aurora Colorado Posts: 370 Car 1: 1994 Black Type II 6-Speed Coupe iTrader: (0)	Thanks cole __________________ http://www.imagestation.com/picture/...0/eef09e67.jpg

05-05-04, 03:09 PM	#15 (permalink)
Badjack10 Registered User Join Date: Feb 2004 Location: Phoenix OR. Posts: 379 Car 1: 1989 acura legend ll coupe iTrader: (0)	you think this would work on a g1?

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