Yes Andy, just the man I was wanting to chat with! Yes its the Delta FK-35 like your's, only I'm using a 95 Taurus (2 speed) fan with the DCC controller wired to the high speed wire. I've also got the DCC linear LED to help gauge what speed the fan is running at.

Does your fan run at all at highway speeds?

 

Dude I've been researching the toyota cooling systems on the 3.0 and 3.4. From what I've found it seems the one area Toyota left for expansion is t-stat. Not opening temp but flow at temp. I looked at the stock stat for the 3.4 and it is pretty big and yet TRD made a larger one for FI applications on the 3.4. I would see if you can compare the one you baught and the one from the Dealership.

The other thing is the fan itself, if you are using a hayden, flex-a-lite or like then dump it. They don't cool a NA 3.0 there is no way they will pull enough air to cool your engine. Before you start hacking into your grill etc. Look at the ammount of space there is between the grill and the rad, once the fan is going there is more then enough room for air to get in there. Your fan is likely pulling more then enough air at idle but when at highway rpms its likely maxxed out all the time. As soon as you hit a harder trail your fan will really show its worth. Start ruling out the things you have changed before you take the knife to body parts, MHO.

 

I'm running the URD (NAPA) 170 deg t-stat, and yes it opens bigger than the stocker does. I really don't think coolant flow is a problem but I'll try the TRD t-stat if it comes to that.

Yes the fan is pulling air through good, I don't believe it is maxed out yet (definately not at slow rock crawling speeds), but time will tell for sure. The question is why is the fan needing to run at highway speeds, shouldn't there be enough natural air flow at 70 mph? There is a lot in the way in front of the radiator. The bumper, winch, AC condensor, 2 transmission coolers, and a lot of plastic grill.

 

Dude, your not exactly running a stock setup, that engine is gonna make a lot of heat. I've read a few writeups on blown 3.4s and they made some mad heat. Seriously put the stock fan back on and see what you have, start ruling things out. If you already flowing more coolant through the stat then leave it alone. Some people with the taurus fan have had cooling problems cause it doesn't pull enough air at highway speeds, those aftermarked fans pull about a third of the air the taurus does.

 

Yeah I'm strongly considering the stock fan, I'll probably do that before I cut my custom shroud up. So are you saying it's normal for the e-fan to run at highway speeds?

 

No, it is not normal for the e-fan to run at highway speeds. My Taurus fan / DCC FK-35 Controller doesn't.

Something is limiting flow through the radiator at highway speeds, my guess would be a combination of everything, but mainly redirection of flow by your TJM... I'm thinking custom ram-air ducts might be able to help with that, either in or under the bumper. When the cooling system is working properly, you should be able to drive on the highway with your fan off.

Also, maybe a hood lift would help give you a cowl effect, helping more air blow through the engine compartment?

 

Ooooh, ram-air ducts.

 

My suggestion, dryer hose

J/K

 

Ok I set the fan controller to come on at about 15 deg cooler than before but the OBDII temp reading got up to 183 before the t-stat even opened. But once the engine was good and hot it stayed about 180 at idle with the fan bearly running. Cruising at 70mph it got up to 193, about 10 degrees cooler than the same test yesterday) everything else was about the same (same road, distance, speed, and ambient temp). So the good news is the fan wasn't maxed before, but it may be now.

 

I'm saying that the stock fan turns all the time at different rates depending on temp. FWIW the t-stat is fully open at 203 degrees-f. You seem to have harrowed it down to the fan by changing the settings on your controller. I'd get the one that changes the fan speed gradually rather then on/off.

 

my fans only run at low speeds on the highway, they're off and just spin from the forced air.

1. are you sure that the radiator you have is sufficient in size and efficiency?
2. are you sure that the system is properly bled of all air bubbles?
3. if 1 and 2 are good, then take off your skid (if you have one) and see if that helps any. as a last resort, take the hood off and go for a drive and see if the temps still spike. if they do, then you have cooling system (i.e radiator or WP) issues and not fan speed or CFM issues.

also, on the volvo fan, it had a "control" box of sorts that had three leads into it (fan speeds and ground) and then two leads from the box to the motor. i took that box off and hooked the DCC directly to the fan motor leads. when i initially hooked it up to the volvo controller box, the fan speed was super slow. now the DCC controls the full range of speed, and not just the speed within the pre-defined window that the box allows it to.

 

Well, it sounds to me like your t-stat may be opening a little late for a 170 deg, and your radiator may be undersized for your application. We need to figure out how to get more air blowing through that thing on the highway, so your fan doesn't have to work so hard.

Going along with what Bamachem is getting at, even though this would be a big PITA your best chance is to take off your TJM and drive on the highway to see if the air blockage is your problem... (don't hate me)

 

You're not understanding, he has the DCC FK-35 fan controller. It IS a variable controller. He also has a 170 degree t-stat, which makes me think it should be full open around there, not 203. Stock t-stat is 190 deg, isn't it?

 

Aah I get it. I went to the dealer to get specs on the stat for both my 3.0 and the 3.4 Here is what it says:

-Valve opening temp 176-183
-valve lift is 8.5mm at 203
-valve fully closed at 104

IDK the specs on your Napa one but I'll bet it works simularly if only at a lower temp.

 

Oh you mean the Delta Current Controller, got it.

 

Not sure.

Actually for the test drive yesterday it was off.

Yeah its wired directly to the motor (high speed wire).

 

I agree, I wish I had the TRD 160 deg t-stat now. I tested this one on the stove before I installed it and it did start to open about 170.

Yeah taking the bumper off is a PITA all right

 

It's 180

 

Well Dale, I dunno. What's the plan?

 

I don't know, do you think 193 is too hot? May wait and see what some of you other guys are getting for temps. I'm not pinging any that I can tell. I'm tempted to put the stock fan on and try that. Also tempted to cut the grill open some.