'06 heated throttle body & Defi oil pressure install

Wazazell · 11-22-2005, 05:05 PM

I ran into something unexpected when installing my Defi oil pressure sensor this weekend. I installed the sensor in the oil galley using the replacement galley plug that I ordered. Everything is installed and working now, no leaks, but during the install I had a little trouble.

Right in front of the location of the oil galley plug there is a nipple that feeds coolant to the throttle body. I hadn't seen this in any of the pics of other people's installs and it turns out that it makes things very cramped for the oil pressure sensor. I had to cut about a 1/4" off the end of the hose and shove it on as far as it would go in order to clear the sensor, and it is still nearly kinked. I'm not too thrilled about that, but it doesn't seem to be causing a problem.... and hopefully won't...

Here's a pic of the sensor, and the hose that caused me the problem. Is this present on '04/05 models? If you look real close, there's a whole aluminum assembly under the intake manifold, some kind of manifold heater? It's very shiny and you can just make out "S U |" on it.

Here's a pic of Marsh's install on his '05. I don't see the hose or nipple in any of his pics.

http://homepage.mac.com/jsalicru/PhotoAlbum131.html

If I had to do it over again, I would probably just T into the stock oil sensor in the front, but I thought I'd be clever and use the rear location instead...
So, be warned '06 owners!!

Xman · 11-22-2005, 05:16 PM

that's definitely different than an 04. Here's a different angle on my TB hose rerouting. http://www.cl50.com/xweb/My%20STi/Mo...%20resized.JPG

Wazazell · 11-22-2005, 05:18 PM

Here's another pic of the hose...

Rootus · 11-22-2005, 07:04 PM

Fascinating. Thanks for the heads-up! I've got the galley plug & washer on order, and my Omori gauge is sitting here waiting to go on. I'll add some extra time to my plans.

Dave

disillusioned · 11-22-2005, 07:24 PM

my old sentra had something similar, where there was a coolant line going into and out of the throttle body.

with the sentra, we would just re route the coolant lines so there wouldnt be any coolant passing thru the throttle body.

but, since im in such a warm climate, running coolant thru the throttle body wasnt the best thing to do. plus, winter time here doesnt go under low 50s, so yeah.

i wonder if bypassing the coolant line the 06 STi would be detrimental to the health of the car?

Wazazell · 11-23-2005, 05:12 AM

Quote:

Originally Posted by Rootus

Fascinating. Thanks for the heads-up! I've got the galley plug & washer on order, and my Omori gauge is sitting here waiting to go on. I'll add some extra time to my plans.

Dave

you could always remote mount the sensor with a piece of braided flex line... that would make using the galley plug easier, but it probably wouldn't be worth the trouble. Like I said, for peace of mind, if I had to do it again I'd probably just T in with the stock sensor...

Good luck!

Another word of caution if you do use the rear galley plug. Removing the stock plug pissed me off too. They put some kind of pink thread locker on the plug, so it requires a lot of force to break free, which freaked me out a little. Then once I got the thing unscrewed, all that pink thread locker crumbled off and into the galley hole!! I had to duct tape a piece of garden hose onto my shop-vac hose and try to vacuum it out. It sucked up a good bit of oil out of the galley, so I'm not too worried, but it was irritating!

Rootus · 11-24-2005, 05:22 AM

I'm hoping to have a somewhat easier time because the temperature sensor that came with my Omori gauge looks like it is a lot narrower than the pressure sensor you're using.

Thanks for the note about the threadlocker ... I'll be keeping that shopvac handy as I unscrew the old plug

.

Dave

aspensti05 · 11-24-2005, 06:17 AM

Quote:

Originally Posted by Xman

that's definitely different than an 04. Here's a different angle on my TB hose rerouting. http://www.cl50.com/xweb/My%20STi/Mo...%20resized.JPG

What is the gain or reason for keeping coolant from the TB?

Xman · 11-24-2005, 08:06 AM

well, keeping 150+ degree coolant out of my throttle body can only help keep the intake charge slightly cooler.

Just as putting the heat shield between the turbo and IC. At speed it's not gonna make a huge difference because of airflow through the hood scoop, but it sure doesn't hurt for when you are sitting still.

rube23 · 11-24-2005, 01:21 PM

Although I havent looked at it to confirm, if this coolant running around the throttle body serves the same purpose as numerous other fuel injected cars (for ex: my last 5.0 mustang) then it isnt there so much as a heated throttle body but rather to cool the throttle body due to the EGR valve dumping hot exhaust gases through it. In the mustang world, people originally used to bypass that coolant line, but later dyno tests proved people actually loosing power due to the intake charge actually being hotter without that coolant line being hooked up. If you really want to do something, plug the EGR and then plug that coolant line.

Xman · 11-24-2005, 02:33 PM

I would agree, but there is no EGR in this setup.

here's a system overview PDF from the 2004 service manual. No mention of EGR and I have never come across one while tearing them down. If you can find one, I'll buy you a beer.

http://www.cl50.com/xweb/STi%20Manua...20Overview.pdf

I suppose I should run some pryometer tests on the surface of the TB with and without the coolant line routed to verify but I trusted the top rally tuners who do this and figured their years with prodrive and other group N programs were probably good enough to base it on. I shall gather data. It's a good excuse to get my hands dirty.

rube23 · 11-24-2005, 02:57 PM

Is that coolant line present on the 04?

Xman · 11-24-2005, 03:06 PM

the coolant lines are a bit different in 04 but the throttle body still has coolant running through it. The big silver box underneath the manifold is not on the 04, so I think the lines are routed a bit differntly but the basic functionality is probably very similar.

caelismadison · 11-24-2005, 03:42 PM

On VWs they have the coolant running thru the t body as well and I have seen and also have done the bypass on my vr6 cars. I was a VW tech adn asked a guy at VW tech line exactly what it was for and I was told it was mainy used to heat up the intake air for cold start emissions. So the cars o2 sensors would heat up quicker and then use the o2 to monitor A/F ratio.
Possibly for de-iceing a t body in the extreme cold?

pepito · 11-24-2005, 08:49 PM

Quote:

Originally Posted by Wazazell

you could always remote mount the sensor with a piece of braided flex line... that would make using the galley plug easier, but it probably wouldn't be worth the trouble.

This is what I did with my Omori gauge.
BUT YOU GOT TO COVER THE BRAIDED FLEX LINE BECAUSE IT WILL RUB A HOLE IN THE COOLANT LINE, BE CAREFULL, I USED A PLASTIC WIRE COVER.

11-22-2005, 05:05 PM	#1
Wazazell Silver Member Car: 2006 STi Fav Mod: power adding stickers & emblems Location: Richmond, Virginia Posts: 956 Join Date: Aug 2004 Trader Rating: (0)	'06 heated throttle body & Defi oil pressure install I ran into something unexpected when installing my Defi oil pressure sensor this weekend. I installed the sensor in the oil galley using the replacement galley plug that I ordered. Everything is installed and working now, no leaks, but during the install I had a little trouble. Right in front of the location of the oil galley plug there is a nipple that feeds coolant to the throttle body. I hadn't seen this in any of the pics of other people's installs and it turns out that it makes things very cramped for the oil pressure sensor. I had to cut about a 1/4" off the end of the hose and shove it on as far as it would go in order to clear the sensor, and it is still nearly kinked. I'm not too thrilled about that, but it doesn't seem to be causing a problem.... and hopefully won't... Here's a pic of the sensor, and the hose that caused me the problem. Is this present on '04/05 models? If you look real close, there's a whole aluminum assembly under the intake manifold, some kind of manifold heater? It's very shiny and you can just make out "S U \|" on it. Here's a pic of Marsh's install on his '05. I don't see the hose or nipple in any of his pics. http://homepage.mac.com/jsalicru/PhotoAlbum131.html If I had to do it over again, I would probably just T into the stock oil sensor in the front, but I thought I'd be clever and use the rear location instead... So, be warned '06 owners!! This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by Wazazell : 11-22-2005 at 05:08 PM.

11-24-2005, 03:42 PM	#14
caelismadison Amateur STI Driver Car: 06 AW STI Location: Dunedin, fl Posts: 49 Join Date: Nov 2005 Trader Rating: (0)	On VWs they have the coolant running thru the t body as well and I have seen and also have done the bypass on my vr6 cars. I was a VW tech adn asked a guy at VW tech line exactly what it was for and I was told it was mainy used to heat up the intake air for cold start emissions. So the cars o2 sensors would heat up quicker and then use the o2 to monitor A/F ratio. Possibly for de-iceing a t body in the extreme cold? Last edited by caelismadison : 11-24-2005 at 04:47 PM.

11-22-2005, 05:16 PM	#2
Xman S204 Racer Car: 2004 STi Fav Mod: Momo fixed back seat, harness bar and Willans 6 point harness Location: Rancho Santa Margarita, C Posts: 2,827 Join Date: Apr 2003 Trader Rating: (3)	that's definitely different than an 04. Here's a different angle on my TB hose rerouting. http://www.cl50.com/xweb/My%20STi/Mo...%20resized.JPG

11-22-2005, 05:18 PM	#3
Wazazell Silver Member Car: 2006 STi Fav Mod: power adding stickers & emblems Location: Richmond, Virginia Posts: 956 Join Date: Aug 2004 Trader Rating: (0)	Here's another pic of the hose...

11-22-2005, 07:04 PM	#4
Rootus S204 Racer Location: Mahan, OR Posts: 2,905 Join Date: Sep 2005 Trader Rating: (1)	Fascinating. Thanks for the heads-up! I've got the galley plug & washer on order, and my Omori gauge is sitting here waiting to go on. I'll add some extra time to my plans. Dave

11-22-2005, 07:24 PM	#5
disillusioned Junior STI Driver Car: 06 STi Fav Mod: Sabelt 3 inch harness Location: miami Posts: 95 Join Date: Nov 2005 Trader Rating: (0)	my old sentra had something similar, where there was a coolant line going into and out of the throttle body. with the sentra, we would just re route the coolant lines so there wouldnt be any coolant passing thru the throttle body. but, since im in such a warm climate, running coolant thru the throttle body wasnt the best thing to do. plus, winter time here doesnt go under low 50s, so yeah. i wonder if bypassing the coolant line the 06 STi would be detrimental to the health of the car?

11-24-2005, 05:22 AM	#7
Rootus S204 Racer Location: Mahan, OR Posts: 2,905 Join Date: Sep 2005 Trader Rating: (1)	I'm hoping to have a somewhat easier time because the temperature sensor that came with my Omori gauge looks like it is a lot narrower than the pressure sensor you're using. Thanks for the note about the threadlocker ... I'll be keeping that shopvac handy as I unscrew the old plug . Dave

11-24-2005, 08:06 AM	#9
Xman S204 Racer Car: 2004 STi Fav Mod: Momo fixed back seat, harness bar and Willans 6 point harness Location: Rancho Santa Margarita, C Posts: 2,827 Join Date: Apr 2003 Trader Rating: (3)	well, keeping 150+ degree coolant out of my throttle body can only help keep the intake charge slightly cooler. Just as putting the heat shield between the turbo and IC. At speed it's not gonna make a huge difference because of airflow through the hood scoop, but it sure doesn't hurt for when you are sitting still.

11-24-2005, 01:21 PM	#10
rube23 HowTo Contributor Car: 06 STi Fav Mod: LED Windshield Washer Nozzles Location: NYC Posts: 352 Join Date: Jul 2005 Trader Rating: (3)	Although I havent looked at it to confirm, if this coolant running around the throttle body serves the same purpose as numerous other fuel injected cars (for ex: my last 5.0 mustang) then it isnt there so much as a heated throttle body but rather to cool the throttle body due to the EGR valve dumping hot exhaust gases through it. In the mustang world, people originally used to bypass that coolant line, but later dyno tests proved people actually loosing power due to the intake charge actually being hotter without that coolant line being hooked up. If you really want to do something, plug the EGR and then plug that coolant line.

11-24-2005, 02:33 PM	#11
Xman S204 Racer Car: 2004 STi Fav Mod: Momo fixed back seat, harness bar and Willans 6 point harness Location: Rancho Santa Margarita, C Posts: 2,827 Join Date: Apr 2003 Trader Rating: (3)	I would agree, but there is no EGR in this setup. here's a system overview PDF from the 2004 service manual. No mention of EGR and I have never come across one while tearing them down. If you can find one, I'll buy you a beer. http://www.cl50.com/xweb/STi%20Manua...20Overview.pdf I suppose I should run some pryometer tests on the surface of the TB with and without the coolant line routed to verify but I trusted the top rally tuners who do this and figured their years with prodrive and other group N programs were probably good enough to base it on. I shall gather data. It's a good excuse to get my hands dirty.

11-24-2005, 02:57 PM	#12
rube23 HowTo Contributor Car: 06 STi Fav Mod: LED Windshield Washer Nozzles Location: NYC Posts: 352 Join Date: Jul 2005 Trader Rating: (3)	Is that coolant line present on the 04?

11-24-2005, 03:06 PM	#13
Xman S204 Racer Car: 2004 STi Fav Mod: Momo fixed back seat, harness bar and Willans 6 point harness Location: Rancho Santa Margarita, C Posts: 2,827 Join Date: Apr 2003 Trader Rating: (3)	the coolant lines are a bit different in 04 but the throttle body still has coolant running through it. The big silver box underneath the manifold is not on the 04, so I think the lines are routed a bit differntly but the basic functionality is probably very similar.