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Cooling System Overhaul - Stumped and Frustrated

dhcomp

dhcomp

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So, my 94 blazer, (175k on it when i sold it), NEVER heated up, no matter how hard i tried. 45 min tow's up grades with the A/C on in 100˚ heat, the gauge wouldn't budge.

The burb on the other hand, starts to heat up pulling its own weight up the grade.

Replaced the water pump right after i got it, no improvement. Since then, have replaced water pump, tstat, radiator cap, hoses, fan clutch....all with no real improvement.

The truck now has 250k on it, and for all i know, could be the original radiator.

What can i do to help the cooling out? Radiator flush, block flush?

I know i could pull the radiator and get it flushed/boiled, but really, at this point in its life, its probably time for a swap.

Thinking new pump, radiator, etc.

Whats the best way to go with stock like replacement radiators? Brand, materials, etc?

While i'm at it, anyone want to explain the different between single and multiple core radiators? I've been clueless on this forever....

Thanks!
 
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When you replaced all of this, did you ever find corrosion/sludge/rust? Are the vanes of your radiator clean and straight or are they smashed flat (blocking air flow).

Radiator rows: If your coolant in a single row radiator is a car on a single-lane highway, then a dual-row radiator would be like opening up a second lane on the highway - more 'cars' traveling the same path in parallel lanes- more flow, more liquid capacity, and more cooling capacity. A multi-row radiator will be physically thicker than a single row radiator, but this is not an issue on K-5s. If you want a multi-row radiator, buy a replacement radiator for a diesel blazer. I have one. Truck never wants to overheat - even in the Alabama heat.

edit: The diesel radiator is a 4-row
 
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The core supports in these are the same that were in every style gm truck/k5 of the time. So they have all the bolt holes there to mount bigger or smaller radiators. Buy a 4 core one for a big block or something and it really should fit with minor modifications. I put a really nice aluminum northern one in mine that has 2 rows in it but they are much wider than the stock rows. Its at least 2.5" thick and the stock one was about half that. Keeps my 408 small block cool all day long, and they are notorious motors for overheating because of the super thin sidewalls.
 
So, i like the idea of going to a bigger radiator, but curious to the extent of said "minor modifications".

What has to change? Do i end up needing different hoses? What happens to the shroud? Different mounts? This will all be swapped in a night....so "stock" fit is important.

Now that i think about it more, my current lower hose is in a wierd kinda pinched position. That probably doesn't help.
 
So, all this "with a/c" , without a/c, max cooling, etc.

What changes on the radiator for a/c vs non a/c? Size?

Wtf is Max cooling?

Do they all have ATF coolers built in?
 
Radiator has nothing to do with A/C except it's mounted behind the condenser. Maybe the mounts are different, but I don't think so. I don't remember having this issue.
 
Any construction type or brand that is better than others? I know some of the badass aftermarket ones like Becool rock, but looking more along the lines of stock replacement.

Hoping to stay away from plastic tanks.
 
dhcomp said:
So, all this "with a/c" , without a/c, max cooling, etc.

What changes on the radiator for a/c vs non a/c? Size?

Wtf is Max cooling?

Do they all have ATF coolers built in?
Click to expand...

no, the manual trans radiators do not have the ATF cooler, BUT they (diesel radiators) do have engine oil coolers (in the passenger side tank) that should be easily adaptable to ATF...

dhcomp said:
Any construction type or brand that is better than others? I know some of the badass aftermarket ones like Becool rock, but looking more along the lines of stock replacement.

Hoping to stay away from plastic tanks.
Click to expand...

i bought an aluminum radiator from Shepard on Amazon, and while it works, it does not fit the supports/shroud very well. i had to weather strip here and there. another question mark is the engine oil/ATF coolers built into them. they are simple hollow tubes, not the stacked plate coolers that the stock radiators have built in.
 
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Just go down to the local NAPA with your truck. I put in a $110 aluminum radiator with plastic tanks a couple years ago, and haven't had any problems. If you want something more bullet proof, NAPA sells an all brass/copper setup for our trucks for $365.
 
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If your not looking to upgrade, or do any modification. Buy the stock replacement and be done. Im sure yours is just full of crud and not cooling to its full potential. Plastic tanks wont hurt you any, and they will save at the bank.
 
Deuling said:
If your not looking to upgrade, or do any modification. Buy the stock replacement and be done. Im sure yours is just full of crud and not cooling to its full potential. Plastic tanks wont hurt you any, and they will save at the bank.
Click to expand...


I'm ok upgrading and modifying, just want to make sure i understand the upgrades/modification before i get in there.

I've cracked plastic tanks in the past, and would like to avoid them....but it will come down to cost.

I need to measure the current one i have, and go from there. I have an aux factory oil cooler, and am using the radiator cooler for my trans (in addition to a larger trans fluid cooler).

Im comfortable with upgrade in the $2-300 range, but not spending more than that.

Thanks!
 
FYI the measurements on a radiator are of the core only, not the tanks.

On mine I had to trim the shroud a bit with a hack saw (easy)

And since mine was a little shorter I made 2 brackets to hold the rad in place, then the stock 2 that hold the shroud on worked fine
 
My Sub has a 4 core out of a big block square body. I had it rotted out and the tanks brazed. while it was out I put a 180* tstat, new hoses. It runs at 180* down the road, but when at a stop with the A/C on in the summer heat it creeps up to about 200, nature of the beast due to, in order from front to back, trans and power steering cooler + A/C condenser then the Rad gets what cool air is left not to mention the mechanical fan doesnt really provide much for cooling. An aluminum rad will dissipate heat better and take up less room. Also electric puller fans would also help a lot, all things I plan on doing to help cool the beast. Good Luck.
 
my 91 is like yours, heats up going up hills or on freeway, in town its fine, new hoses, coolant, thermostat, fan clutch.

napa wanted $202 for a brass core plastic tank radiator, i dont like plastic tanks.

my new radiator is suppose to be here tomorrow according to fedex. aluminum core, aluminum tanks, 2 row. $145


http://www.genesisautoparts.com/

i also ordered a ford windstarfan assembly for it.
 
something odd that napa told me also is they dont do 3 core radiators anymore, just 2 core and they make them wider.

that makes no sense to me
 
Thanks for the tips guys!

Ended up with a vista pro from rock auto, spec'd for the truck. Full brass core/tanks.

Didn't want to deal with moving all the crap i've added to the back of the core support where the larger radiator would live.

New Radiator, cap, tstat, hoses, and pump. No more part store crap! I've probably changed the pump on this truck 3x in 50k. Delco pump, staun cap/tstat, and gates hoses.

Should be good to go for a long while.

Thanks!
 
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