I know I am needing to do a VC-9 flush just to have it done since I am right at 50k on this oil cooler, but I am wondering if anyone has done this and seen much drop in coolant temps? When towing my 10k lb fifth wheel I notice when it is warm enough outside that I need to run the AC that the truck tends to run on the warm side(215-230*) Once it hits 230 I turn heater on and roll down windows and temp drops within a minute to 200. Then every thing is fine for a while or until I have to pull another big hill. Fan won't kick into full blast until over 235* but I have always heard that the 6.0 fan doesn"t kick in fast enough to keep things under control. If you get hot, you will get too hot before fan helps. Just wondering if the flush would help with this issue. Thanks

 

Also wondering if the SCT III is capable of programming the fan to put out 100% at lower temps than factory setting?

 

My ECT drops quick when the fan kicks in to high gear. Is your EGR valve plugged in? Have you talked to Matt about towing with the tunes you have? Here's some insight into fan operation posted by Bismic in the Tech folder under "temps and pressures":

Some say fan kicks on at 210, some say 215, others say 220. Full explanation: Engine temperature is not the only parameter that the PCM monitors to determine cooling fan operation. This is the reason that you will see some variation in engine temperature as it correlates to fan operation. The operation/description of the FSS (Fan Speed Sensor) from the PC/ED manual has a fairly good explanation as to how the system "thinks". This is not your traditional engine hits temp X and the fan clutch locks up. The fan speed sensor is a Hall-Effect sensor integral to the vistronic drive fan (VDF). The powertrain control module (PCM) will monitor sensor inputs and control the VDF speed based upon engine coolant temperature (ECT), transmission fluid temperature (TFT) and intake air temperature (IAT) requirements. When an increase in fan speed for vehicle cooling is requested, the PCM will monitor the FSS signal and output the required pulse width modulated (PWM) signal to a fluid port valve within the VDF. Engine begins to defuel at 221 deg. The thermostat begins to open at about 190*F to 195*F and is not fully open until about 215*F to 219*F..

Hope that helps

 

Rusty, I have all of my emissions equipment still intact. I tow with the "Heavy Tow" program from Spartan. Even when I return to stock the truck will run the same when towing. When I am towing my truck usually lives on the 220 mark with spikes up to 235
That is all the higher I will let it get, before I take action. Honestly from everything I have heard, I don't trust the truck to take care of itself if it gets over 235. I have heard it will just keep climbing until it defuels or overheats. I honestly like to tow at 55mph but the truck seems to get hot faster. I know the fan is capable of full power at any RPM, but in that situation it seems like it cools better at higher RPM's?? Kind of a stumper.

 

Didn't know this was a common issue. I had a clogging oil cooler and never turned the A/C off. Are your TFT, EOT, ECT, and IAT within a degree or two of each other after an over night cold soak? May be a problem with the fan clutch or wiring, have you monitored both of these?
FSS 07E022099F 04620509069F 3010 000100040000 FAN SPEED SENSOR
FDC 07E022091F 04624509061F 3010 013103E80000 FAN SPEED DUTY CYCLE

One is the signal FROM the fss, the other is TO the clutch if I'm not mistaken. The SGII can only send questions and display answers. It can't send commands.

 

[quote= Just wondering if the flush would help with this issue. Thanks[/quote]

It has with some.


VC-9 Before and after; Worth the money - Ford Truck Enthusiasts Forums

 

Sorry Rusty, I don't have a scanguage. I just use my trusty old quadzilla to monitor water temp. Every thing seems to work fine this has been an issue from day one, I just have always made do with it. Maybe I am just overthinking the whole issue and need to just let the fan come on full power and see what happens. I am always taking care of the issue before the fan comes on. Thanks for all the input fellas, and maybe I should find myself a scanguage. That will be fun explaining to the wife. HAHA

 

My bad, saw the temp #'s and figured scan gauge. I was think it was one of three things. The temps you were seeing were off a little, the fan wasn't working right, or the. Cooling system
Wasn't working well. If it's the cooling system, a flush could help. It's also caused some folks problems. Either way, the cooling system has to be serviced at some point.

 

What problems has a coolant flush caused?? Just curious before I do it.

 

Chemically flushing the coolant system can clog your oil cooler. Sometimes when the cooler itself is already clogged, using restore and restore plus can clean out some of the mess, but if the rest of the system is nasty then when it breaks loose the oil cooler acts like a filter and catches all the junk. It's why you always flush the system before you replace an oil cooler and not after.

I would be fully committed to and have parts on hand to change out the oil cooler when doing a chemical flush.

 

5000 miles on a backflush and my ECT/EOT spread is still good, 3 to 5 not towing, 7 to 10 towing. My ECT / EOT spread was at 20 to 30 all the time before the backflush.
I did a really good backflush of all the cooling components independently. I was probably lucky that there was no goo in the cooler.
The 20 to 30 spread came on right after dropping the coolant and circulating the crap. I did not backflush at the time.
I did not use any chemical to backflush, just straight water, and I saw the improvement right after. I must say that I had much crap in the Big coolant Radiator, and I finally changed the big rad because it was leaking. I did replace the city water with demineralized water and now use Red Rotella.
So yes there is some success story, but if you have too much goo in it, it would probably not do the trick.