Coolant Temps

dlrecord Learner Dubber

19 posts · joined Sep 2010 · 1 Jun 2011, 4:24 am

#843966

Hi all,

1979 Bay Westy Deluxe with a 2.2LSubaru N/A and belly mounted radiator between the rails.

My question is about auto fan kick on and coolant temps. On our first day trip yesterday up the mountain, my fans were kicking on around 177*F. I hit a top temp of 212*F on a long and sustained pull up hill. I found the following graphic courtesy of ElusiveStranger (I believe) and am wondering if my coolant sensor is way too low for my engine?

My current aftermarket sensor is a 185*F and I was planning to up it to 195* as I believed that was what stock Subaru is. But the graphic above makes me wonder if I should be going up to 205*F? Thoughts? My system is a simple aftermarket dual fan set up with two relays and wiring kit. It is independent of the ECU. I have a manual override switch on the dash but the sensor should do most of the work while the bus is running.

Thoughts and advice appreciated!

1979 Westfalia Campmobile Deluxe
2.0L EFI, 090 auto transmission

-----------------------------------------
Subaru 2.2L conversion project
http://1979vwconversion.blogspot.com/2010/09/start.html

ElusiveStranger Officially Full-On Dubber

330 posts · joined May 2006 · 1 Jun 2011, 8:44 am

#843986

Just answered it on your other thread on here. Yes, it's waaaaaaaaaaaaay too low. Your stat's not even fully open when your fan kicks in

Use your ECU to control it or set your independent sensor to 95C and be done with it.

Joel Now containing 100\% E-Wang

9,368 posts · joined Feb 2006 · 1 Jun 2011, 9:46 am

#844001

ElusiveStranger wrote:Use your ECU to control it.

This.

Several reasons.
Firstly the computer knows the ideal temps and it also Idles up so theres no voltage or rev fluctuation with the fan running

And secondly the temp coming out of the block is important, not all the way at the radiator.

What year EJ22?
its only the last ones in the mid to late 90s that run staged fans like the diagram above.

The rest just switch the fan on at 96c and off 90c.

dlrecord Learner Dubber

19 posts · joined Sep 2010 · 1 Jun 2011, 11:59 am

#844022

Thanks guys. I debated running the radiator fans off the ecu but decided to take the simple route (in my mind at the time). My fan system is set up independent of the ecu, so it will be based on temp totally instead of temp and speed. I'll get the right sensor and run it.

On a potentially related thought, my warm idle seems to be right around 1300 rpms, which is more like cold start idle temps correct? Could the sensor be keeping the system in a cold idle loop and thus keeping the rpms so high? When warm, if I drop it into drive, the rpms will drop to around 800±. Otherwise in park it sits just north of 1300 rpms...

1979 Westfalia Campmobile Deluxe
2.0L EFI, 090 auto transmission

-----------------------------------------
Subaru 2.2L conversion project
http://1979vwconversion.blogspot.com/2010/09/start.html

ElusiveStranger Officially Full-On Dubber

330 posts · joined May 2006 · 2 Jun 2011, 4:59 am

#844192

Just typing out loud here...did you have aircon fitted? The engine will idle up if it thinks the a/c's running (IIRC)

dlrecord Learner Dubber

19 posts · joined Sep 2010 · 2 Jun 2011, 6:22 am

#844195

No A/C fitted yet. It is on the list to do but is not there yet.

I just purchased a 210* thermo switch and will install and see if that has any effect.

1979 Westfalia Campmobile Deluxe
2.0L EFI, 090 auto transmission

-----------------------------------------
Subaru 2.2L conversion project
http://1979vwconversion.blogspot.com/2010/09/start.html

ElusiveStranger Officially Full-On Dubber

330 posts · joined May 2006 · 11 Jun 2011, 10:54 am

#845704

What bus are you running this in? T2/T3?
Subaru spent millions in sorting the cooling system.

We (well some of us) feck up their logic as we stick the rad lower than they (Scooby) intended - this causes grief (inherent grief)
Overcome this and all's well.

Stuff your switch - if it is a separate system?

Do it right 🙂