Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 05-20-2012, 07:58 PM   #1
Docsuby79
Scooby Newbie
 
Member#: 173994
Join Date: Mar 2008
Chapter/Region: MWSOC
Location: Indianola, IA
Vehicle:
2003 Impreza WRX
Rally Blue

Default Coolant flow direction

I know this sound stupid, but, I've had an argument with my mechanic and I want to verify I'm right. The engine coolant flows from bottom to top, or top to bottom. Meaning does the pump pull or push the fluid from the radiator.
* Registered users of the site do not see these ads.
Docsuby79 is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 05-20-2012, 08:28 PM   #2
UK-Wagon
Scooby Specialist
 
Member#: 232430
Join Date: Dec 2009
Chapter/Region: SCIC
Location: On the Left side
Vehicle:
555 XTi
1 AW & 1 CGM

Default

coolant flow is ALWAYS top to bottom in the radiator. The hot fluid is cooled as it goes down the radiator tubes. The Water pump is is there to create flow direction. Its neither a push or pull, those two are the same in a way lol. Coolant flows by tempature and pressure. The water pump just directs that flow of fluid. When water or coolant gets hot it expands, causing pressure, when it builds pressure it moves faster. So the water pump is there to direct that flow of fluid pressure. Therefor the WP really isnt pushing or pulling....

If you think of cold coolant, the water pump pulls fluid from the radiator and then pushes it through the engine. So its sorta both until it warms up.

All radiators flow the same for just about anything, hot comes in the top, cold goes out the bottom. Let your car warm up, touch the top hose, itll be really hot, then touch the bottom, itll be warm.
UK-Wagon is offline   Reply With Quote
Old 05-20-2012, 11:44 PM   #3
WhiteBgeye02
Scooby Specialist
 
Member#: 224785
Join Date: Sep 2009
Chapter/Region: MWSOC
Location: neenah
Vehicle:
2005 wrx-jdm207
i went black...

Default

as said it pushes and pulls at the same time. it pulls water from the in hose and pushes it out the outlet hose. i am unsure what makes me think this but i was told i should put the water coolant temp in the bottom hose since its off engine temp while the top hose will give me a reading but will be cooler. i honestly would have to look to verify which way it goes.
WhiteBgeye02 is offline   Reply With Quote
Old 05-21-2012, 01:54 AM   #4
UK-Wagon
Scooby Specialist
 
Member#: 232430
Join Date: Dec 2009
Chapter/Region: SCIC
Location: On the Left side
Vehicle:
555 XTi
1 AW & 1 CGM

Default

Quote:
Originally Posted by WhiteBgeye02 View Post
i was told i should put the water coolant temp in the bottom hose since its off engine temp while the top hose will give me a reading but will be cooler. i honestly would have to look to verify which way it goes.
wait what? no the bottom hose will be cool, the top hose will be hot. You want the sensor at the top to give you the engines actual temperature. Putting it in the bottom would give you the cooled down radiator temp.
UK-Wagon is offline   Reply With Quote
Old 02-20-2021, 08:55 PM   #5
TXwrxWagon
Scooby Specialist
 
Member#: 191557
Join Date: Oct 2008
Chapter/Region: TXIC
Location: Rockwall-East DFW
Vehicle:
2004 WRX Wagon
WRB not so minty fresh

Default

i've been having this discussion with several very knowledgeable engine builders and technically both schools are correct, kinda.

Its a cooling management philosophy really. Hear me out.

One school (the most common) is that you want to use the TOP hose to see what coolant temp is exiting the engine and kick fans on accordingly. Hence why the OE temp sender is in the block. Right? Kinda...
.
The second school of thought is about MANAGING engine temp with proper airflow and assuring the radiator is doing its Job effectively. Again hence why the old "sure fire test" is top hose should be almost too hot to hold with the bare hand and the lower should be warm, This is foundation of the @nd school of thought, which I tend to build my engines and systems this way.

By placing the temp sender in the lower hose or, if available in the jacket around the water pump area if possible, you are reading the Radiator/Fan combination's ability to MANAGE temperature.

The Prosport in hose coolant sender adaptor instructions say in the UPPER hose Which is great. Im installing mine in the lower exactly half way in the hose. With both my Prosport gauge sender and my 2ndary fan temp override.

Now I have BOTH. I've owned my 04 WRX Sport wagon going on 11 years. I've been through 3 radiators, 1 water pump and T-stat, 2 sets of fans. I know where the car runs best on the factory water temp gauge. Now I will be able to dial in a fan override depending on temps and outside/weather conditions. I live out side Dallas, TX and temps can get well over 100* and I also travel 40+ weeks all over the US all continuous 48 states all 4 seasons. The WRX through Death Valley in the Summer, -23* with a wind chill of -43* in Fargo, ND. and everything iun between.

Just last Xmas time I left Crested Butte, Co at 7am with temp -8* and wind chill of -25* by about 2pm I was crossing into NM and temps were nearing 30-35* and at the end of a day 1/2,14 total drive, It was nearly 63* at home.

Heat inside the cabin of the car was never a "problem" but early in the trip it would have been nice to hold the fans back a little while watching top and bottom temps.

the opposite driving through Death Valley, I would have wanted the fans on earlier than the factory settings because the car did run warmer for sure.

Just recently at 300K the aluminum Koyo rad I put in at about 78K took a chunk of road debris and the damage was about a 1.5" whole in the fin/tube area low near the bottom tank. I found a killer deal on a Mishimoto rad. In the process it damaged BOTH factory fans. So I ordered slightly larger fans and aluminum shroud and a Grimmspeed rad cover plate. Full Monty upgrade. Just received the Matching Prosport Oil/water temp premium gauge and an extra sender and an extra sender harness, and the hose sender adapter, and a Dearle adjustable electric fan controller with full on override capability. I plan to use a switch and a relay to use ONE Temp gauge to be able to toggle between oil temp and h20 temp.

Just like My Prosport Oil Pressure gauge is already set up to handle toggle between Oil Press and Fuel Press, just flip a rocker switch.

~Rob
.
TXwrxWagon is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Question About FMIC Piping Flow Direction dan1587wrx Factory 2.5L Turbo Powertrain (EJ Series Factory 2.5L Turbo) 1 11-17-2009 07:58 AM
FMIC flow direction question capnchunk Water/Methanol Injection, Nitrous & Intercooler Cooling 1 12-08-2007 07:41 PM
Oil filter flow direction? cdvma Built Motor Discussion 2 04-23-2007 12:23 AM
cabin filter flow direction.. kcismo Service & Maintenance 2 04-11-2006 12:15 AM
Reverse flow direction on Blitz FMIC dan avoN7 Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 5 01-02-2005 07:50 AM

All times are GMT -4. The time now is 08:46 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.