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Making the truck run cooler (cheaply)

84k5

84k5

1/2 ton status
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May 13, 2000
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Dublin, CA
I need my truck to cool itself a bit better. Looking for cheap/easy tricks. 90 degrees outside with the heater on full power @ 5 mph brings the suck.

I am not putting in a bigger rad or taking the hood off. Truck will get some good parts next year.:D

So...

Water cools better than anti-freeze, how little anti-freeze can I get away with? Truck won't see anything lower than 20 degrees.

Truck has a 190 degree thermastat, but I don't think a lower one would help since it would be open in this situation either way???

Other ideas???

BTW, I am only having problems at altitude (8K+), so the truck is probably running on the rich side (stock 84 305). Last time it hit 220, I turned on the heat and it dropped to 210, I just want it @ 210 without having the heater on.
 
Hay man you need to put a 160 trermo in it and then mix a 50/50 antifr. and waterthese are simple things that can be done by anyone :doah:
 
It is 50/50 now. I want to know if I can get away with less.
 
I agree I wouldnt mess with the antifreeze, I would put a little cooler thermostat in it and see if it helps any. 210 seems a little too hot to me
 
Does your fan clutch work or is it dead? A bad fan clutch can make a big impact on engine temps...

Rene
 
It always runs @ 210.:dunno: The fan works, is there something more I need to do to check the clutch?
 
Do not use parts store clutches , I tried one when mine died , and it doesn't work . I used another Delco out of the backyard and it cools like it used to . And make sure there is no dried mud in the center on the coil ( Shawn :wink1: ) that would keep it from tightening up when warm .

Oh and also some years had a clutch AND semi rigid fan ( my stock 83's original ) that will flex at higher rpms , use a solid blade GM fan .
 
What are you using to measure the temp? If a stock/old gauge, then that may mean you don't even have a problem. :)

Other than that:

Colder t-stat doesn't matter, you are correct. At 200*, a 160 or 195* stat means nothing. If it gets that hot, your cooling system is inadequate. Whether that means not functioning correctly, or other limiting factors.

You don't need antifreeze. The temp on the bottle for boilover protection is artificial. Those numbers are taken at 15PSI, which increases the boiling temp by much more than antifreeze does. Antifreeze is something like +20* boiling over water at 15PSI. Check out what straight waters boiling point is at 15PSI. :) There are products made to protect the cooling system from corrosion, and to attempt to reduce operating temps. You need at a bare minimum the corrosion protection.

If you are going to run the setup through winter, go with the absolute minimum on the bottle recommended for that min temp or effective corrosion protection. I ran somewhere around 33% this last winter, also down into the teens. But go by the bottles recommendations.

But first, make sure your temp reading is right. 220* really isn't hot for a SBC anyways, it's the factory turn-on temp for the primary fan in my Camaro setup.
 
84k5 said:
It always runs @ 210.:dunno: The fan works, is there something more I need to do to check the clutch?
Click to expand...

Once the motor hits 220 shut it off and see if you can make the fan freewheel. If it spins with little effort the fan clutch isn't working. You should also be able to hear the fan engage and disengage...depending on how many blades your fan is they can be quite loud.

My fan clutch hasn't worked in years (ever?) but a diesel runs colder the longer it idles. If my truck is idling a lot like in heavy traffic the temp will drop from ~200 down to 140-150 in a matter of 10 minutes idling.

I'd probably test the fan clutch, and run a new aftermarket temp gauge with a new sender. I have had many wonky guages over the years, and now don't really trust them to be 100% accurate anymore.

rene
 
The problem is I doubt the cooling system is going to hold 15psi sitting for a week...I am definitly keeping some antifreeze in it.

I'll check the fan clutch...now that I think about it I recall it being kinda janky when I changed the water pump, I bet that is my problem.

I was going off the 21 year old stock guage (:rolleyes:), but it smelled like it burned the oil when I got to the trailhead. It was a great site. My k5 stinking of burnt oil, still running with the key off, surrounded by a bunch of nancy boy hippies with their hybrids and saturns.
 
Also make sure the fan shroud is fitting properly around the fan. Sometimes when body lifts are put on people mess with the shroud so it doesn't hit the fan. Don't know if you have a body lift or not, but thought I'd mention it in case you do.
 
Are u sure the thermostat is opening......i remove the valve in my thermostat so coolant flows constantly.

The lower radiator hose may be collapsing at highway speeds if there is no spring in it.

At highway speeds the fan clutch is worthless, but in traffic it can cause BIG problems if it fails, bring the engine to temp and place yor hand behind the fan
(CAREFULLY :haha: ) if you feel a very strong breeze then the clutch is bad.

No fan shroud will also disable the fan from doing it's job properly.

I would not run less than a 50/50 mix of water/antifreeze.

Air pockets in the cooling system will allow the coolant to expand and raise the operating temp.

DEI makes a additive that will lower operating temps as well.

Get a high-flow aluminum water pump with 40% more flow than stock.
 
have u checked if the rad is gunked up? i put some tow cool stuff in my car and it helped a ton,droppeed temp down to where it shoud be(in the middle of the desert 130* idle trafic w/AC cranked)
 
dyeager535 said:
What are you using to measure the temp? If a stock/old gauge, then that may mean you don't even have a problem. :)
Click to expand...

I just replaced a temp sender . This one was running away and reading way high after about 210 , would even go up to 230 or 240 .

New temp sender from Napa , instead of Autozone and its back to reading normal :D
 
pauly383k10 said:
I just replaced a temp sender . This one was running away and reading way high after about 210 , would even go up to 230 or 240 .

New temp sender from Napa , instead of Autozone and its back to reading normal :D
Click to expand...

Can you by any chance get me the part number for that? I need a couple and they keep selling me f'n idiot light switches instead of senders.
 
Alrighty.

40% of your cooling can be done in your engine oil. If it overheats a lot, run an oil cooler.

50/50 mix of ethylene glycol at sea level has a boiling point of 226°F. If you run a 15lb cap you can get it to around 265°F boiling point. A 15lb cap on pure water will get you around a 245° boiling point. It's about two degrees per psi.

If you run pure water with something like "Water Wetter" it'll have the highest specific heat you can get and will prevent corrosion. It won't do anything for freezing. I wouldn't run regular antifreeze at less than 25%.

Replace your cap regularly. Buy either a 14, 15, or 16lb cap. A bad radiator cap can cause cooling issues. By increasing pressure it increases the boiling point. The critical spot is at the heads where the heat is the highest. If it exceeds that pressure it blows coolant out into the reservoir. When the radiator cools down it creates a vacuum in the cooling system and it sucks coolant back out of the reservoir.
 
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