Overheating with AC on - or... Maybe Not?

its been a while since i have done any mechanic work, about 12 years since i have done anything serious in a shop that wasn't just routine maintenance or small repairs on a family or friends car, but you are telling me that anti-freeze is no longer sweet?

"Don't do this. This is dumb, but I ain't changin' it, because it's awesome." Wise, stupid words. My hat's off to you, sir.

So much going on here but I'll take a swipe at a couple things the must be addressed that I believe are teaching points seldom addressed. Coolant comes in several flavors, and yes they have taken the sweetness out so your cats are less apt to lap in up. It's poisonous and in effect will rot your brain. Selecting the correct coolant will protect the metals internal to the engine, radiator, heater core, etc against galvanic reaction. Any quality brand coolant already has adequate surfactant as part of its chemistry. Avoid playing around with the blend unless you know what you're doing. I'm not a chemist so believe in starting with a thoroughly flushed cooling system. Next, coolant operates best at a 50/50 mix with water. If you add premixed coolant with any water left in the cooling system prior to filling your concentration will be lower. Radiator pressure is imperative. Pressure test your radiator and especially your radiator cap. Even a minor leak at a hose clamp will bleed off pressure over time. Water boils at 212 degrees f at atmospheric pressure. Once boiling you've lost ALL surface contact between the coolant and internal metal surfaces where that boiling in taking place. Unpressurized 50\50 coolant boils at around 230 degrees f and 50\50 coolant pressurized to 15 psi {under a sealed coolant system} boils at or above ~265 degrees f. That's 18 degrees above 212 for having the proper coolant concentration and 35 degrees additional for holding it under pressure. You must maintain pressure on the system to have it operate effectively. Oh.also rince all the straw and seed and cat hair and anything else out of the radiator fins too. Happy motoring.

Modern engines operate at higher coolant temperatures for emission control purposes. With that said, the only thing you need to watch for are the true signs of an overheating engine...

You turn off the engine and it diesels badly and then you hear all the coolant boiling like crazy inside the hoses. As long as that doesn't happen, you are fine.

Personally, my own solution to overheating has always been to add a container that massively expands the amount of coolant in the system. I've run double radiators -- one in front of the other one-- in series. I've used a two gallon metal gas can in the middle of the upper radiator hose. Both systems ended my overheating problems on the spot.

Do you teach them how to grade gas when they're siphoning it too by tasting it?? "Unleaded tastes a little tangy, supreme is kinda sour, and diesel tastes pretty good!"

Something i was told a while back and it worked is there should be minimal space as possible between the condensor ,intercooler and rad that gaps disrupt air flow,also good move putting a spal in,,that and the factory ford mark 8 fan are the best way to go for max cfm and reliabilty. Hope this helps thanks for all the tips,tricks knowledge in your videos

What a conundrum! If you figure that the boiling point of water is 212 degrees (F) and a 14-pound rad cap increases that by about 40 degrees, then the real boiling point is around 250 degrees. With that in mind, 212 doesn't sound too hot but I'm old school too and I would like to see my coolant temp around 180. Interesting discussion about the LS cooling system design. I never really looked into it but what you said makes perfect sense. Part of the reason for the development of the LS had to do with meeting increasing demands to lower emissions and increase efficiency. I've had cars in the past that basically wouldn't idle below 1800 RPM and overheating was pretty normal and they didn't have AC or a turbo with an intercooler so, I wouldn't change the setup on your truck either!

What about putting louvers in the hood? This might increase air flow thru the engine compartment. More air flow more cooling.

Early 90s ford Taurus fan should do the job and has the built in shroud you can cut up and modify.

Take a drive with the hood off, there is a lot going on in that engine compartment and the air may have a hard time getting out. Does not cost much and you could see the check valves in action. We found Jeeps with v8's and lots of goodies have this problem and hood louvers helped a lot.
Good luck.

Its a bit late in this build to source a cross flow radiator??? Suppose to have more travel distance and travel time of fluid thru them to transfer a marginal amount of heat more than a conventional radiator....

Use a 22# cap, tighten your hose clamps and forget it

Hmmm....Likes to taste antifreeze, but hates the smell of gear/dif oil.....that checks out.

Maybe you were supposed to be a chef instead.

This is a journey!

What sensor tells the fan to run? Thanks for the lesson. I did not know this. Me like the TRUCK.

Our 2007 Chevy Express van at work has a 4.8 LS engine in it. Hadn't really thought about the markings on the temp gauge before but 210 is smack dab in the middle and is pretty much where it sits all the time.

My head hurts.. gorgeous truck

An inverted cowl for the hood ("Air dam" style) might help quite a bit with that.

Hi, Here fom Chile. Im repairing the same car for my mom. Her dad had this car back in the 60s and I want to make a surpirse for her. Love your videos. I couldnt find any showind the connections of the dashboard or the choke.