3.6L Radiator Fan Problem?

[SitKneelBend]

Any UPDATES ??? Thanks

Not yet, I have everything to start flushing the radiator except time!

 

[Atcer2018]

I recently went to pick my daughter up from school about 3 hours away. Truck was loaded with her dorm room stuff probably didn’t weigh more than 300 pounds. It was a hot day and the drive back was in the 90’s most of the way. I’ve deleted the AGS shutters on all but the top and bottom rows so the truck has been running at less than 210 in local traffic and 195-205 on regional highways. During the long 90 plus degree drive sometimes doing 70mph+ with the AC on the temps would climb up into the 220’s. If I turned the AC off temps dropped back down to the 210’s. Does anyone else see coolant temps climb with the AC on at highway speeds? I’m assuming this is because the fan is programmed to come on at around 230 and never getting to that temp allows the system to park in the 220’s. Doesn’t using the AC force the fan on or does it still use a temp profile and operate at designated temps only?

 

[SitKneelBend]

I recently went to pick my daughter up from school about 3 hours away. Truck was loaded with her dorm room stuff probably didn’t weigh more than 300 pounds. It was a hot day and the drive back was in the 90’s most of the way. I’ve deleted the AGS shutters on all but the top and bottom rows so the truck has been running at less than 210 in local traffic and 195-205 on regional highways. During the long 90 plus degree drive sometimes doing 70mph+ with the AC on the temps would climb up into the 220’s. If I turned the AC off temps dropped back down to the 210’s. Does anyone else see coolant temps climb with the AC on at highway speeds? I’m assuming this is because the fan is programmed to come on at around 230 and never getting to that temp allows the system to park in the 220’s. Doesn’t using the AC force the fan on or does it still use a temp profile and operate at designated temps only?

From my observations, turning the A/C on will always engage the fan, but hard to tell if that's the case at speed. Typically turning on the A/C has always lowered temps for me however I have only recently started observing it and most of my observations have been done in the low 80s...

 

[Yardbird]

What I've noticed on my 3.6, is that turning on the A/C doesn't automatically start the fan. After the a/c runs a short time, the line pressure will build up and the fan will slowly start, climb in speed, slow down, then stop until pressure rises. This is on cooler days.

On quite warm days the fan will start much sooner and stay on longer. The reason the fan may not come on at highway speed is that the air flowing across the condenser is cooling it off.

I went to the mountains this week on some very long and steep roads. Times before I have seen temps of 228 before the fan cooled the engine off. This time I saw 220 briefly, but the outside air temp was much cooler than last summer when I last went.

I've raised my hood, started my truck cold with the a/c on to see how the fan works in different outside temps. The outside temp makes a good sized difference with how often and how long the fan runs.

I do wish I could program the electric fan to run like all the other vehicles I've owned, instead of head pressure and temperature variable speed. I don't care if the fan wears out quicker. I don't like seeing 220-228 deg plus on the temp gauge.

 

[SoFLRam]

I was having issues with cooling for years. I got ho tuner, went to fans. The high setting was 234°F. Holy smokes. Changed it to 215°F. Put in a 180° F thermostat. Now it doesn't get above 225° F when towing 7k #.

But now I have a code for coolant temp not high enough. Lol

 

[Atcer2018]

I was having issues with cooling for years. I got ho tuner, went to fans. The high setting was 234°F. Holy smokes. Changed it to 215°F. Put in a 180° F thermostat. Now it doesn't get above 225° F when towing 7k #.

But now I have a code for coolant temp not high enough. Lol

I’ve read several posts that the 180 thermostat can cause issues with the emissions programming. I don’t personally like how they set these trucks up to run hot for EPA/emissions numbers. I’ll take a mile or two less per gallon if the engine lasts longer.

 

[Yardbird]

The problem with changing the fan settings on my truck, is how to do it with a locked system.

 

[SoFLRam]

Yes you have to get it unlocked. Hp does it. Either a new PCM or send yours to be unlocked. Without a truck for a few days

 

[04fxdwgi]

I picked up a used PCM off ebay for $65 and sent in to get it unlocked and VIN numbered. Keeping original programmed OEM one on the shelf, just in case.

 

[SitKneelBend]

Tackling the coolant flush. Going in with some Blue Devil oil degreaser for the cooling system too. The coolant looks decent but it seems to be draining slower than I expected...

Edit: scratch that, it's shooting out now but I had to remove the plug completely, it's not coming out of the little drain extension. I guess it has some gunk in it. Waiting for this to cool to flush more...

 

[Atcer2018]

Tackling the coolant flush. Going in with some Blue Devil oil degreaser for the cooling system too. The coolant looks decent but it seems to be draining slower than I expected...

Edit: scratch that, it's shooting out now but I had to remove the plug completely, it's not coming out of the little drain extension. I guess it has some gunk in it. Waiting for this to cool to flush more...

And so little coolant drains using the radiator petcock. System holds almost four gallons and you’re probably only getting a gallon out at every drain. Took me two days to run 10 gallons of distilled water through it.

 

[SitKneelBend]

And so little coolant drains using the radiator petcock. System holds almost four gallons and you’re probably only getting a gallon out at every drain. Took me two days to run 10 gallons of distilled water through it.

...and don't forget how easy it is to break the drain petcock...it'll hold pressure, but it has to be pulled and twisted out now. I picked up a Dorman at Autozone but I'm going to use the broken one for the drain and fills.

 

[SitKneelBend]

I got about 10 gallons of distilled water through/into the cooling system yesterday but the thermostat bleeder and the radiator drain petcock were casualties. I recommend having a spare petcock on hand for the radiator and replacing the thermostat bleeder with one of these which I just ordered...

Brass bleeder:

https://www.amazon.com/gp/product/B07QLN1PN8/ref=ewc_pr_img_1?smid=ATVPDKIKX0DER&psc=1

Drain Petcock:

Amazon.com

Both can be had at local auto parts stores for the same or cheaper.



Don't drink the Kool-Aid...

 

[SitKneelBend]

An observation with running mostly water in the cooling system presently. Temps generally stay the same while operating BUT with almost all water in the system temperatures can drop very quickly. Leaving the highway with coolant temperatures at 217 and Oil at 212 the coolant temperature dropped to 197 coasting to the stop light on the exit ramp. Ambient temperature was 81 degrees and overcast. It seems the system is striving at all times to get the coolant temps up to 220ish in my opinion.

I think I'll run another 10 gallons of distilled water through before adding coolant back into the mix...

 

[star_deceiver]

Does anyone else see coolant temps climb with the AC on at highway speeds? I’m assuming this is because the fan is programmed to come on at around 230 and never getting to that temp allows the system to park in the 220’s.

City driving temps with the Ac.

Highway with the AC. Note, Warlock models don't have grill shutters.

 

[Wild one]

If you can get the block drains to come out,you'll get alot more coolant out of the system,as there's probably a good gallon or more in the bottom of the block that won't drain through the rads petcock

 

[Yardbird]

One thing that could be keeping temps up with a/c is the warm air from the condenser flowing across the radiator.

At road speed my temps are always around 194-197 deg on flat land, mostly 197.

 

[Atcer2018]

If you can get the block drains to come out,you'll get alot more coolant out of the system,as there's probably a good gallon or more in the bottom of the block that won't drain through the rads petcock

I’m lazy Rick, capable but lazy lol

 

[Wild one]

I’m lazy Rick, capable but lazy lol

The older i get,the harder it is to create the ambition to do things,lol
So we're not lazy AT,just lacking ambition

 

[Atcer2018]

City driving temps with the Ac.
View attachment 544098
Highway with the AC. Note, Warlock models don't have grill shutters.
View attachment 544099

Thank you for that information. These are typical temps I see except in Fahrenheit. lol Only when the outside air temp climbed into the 33C range did my coolant temps rise with the AC on at highway speeds. Just not sure why that is as I was expecting the e-fan to bring them down. My truck runs much cooler without the AGS but since it was originally equipped with the shutter system the PCM probably has the cooling profile stored as such for the fan. What’s more concerning is my oil temp is always ten degrees higher than coolant temp after the thermostat opens.