ak diesel driver
6.5 driver
I am curious to know if there is any diff between the Chevs & GMCs as far as one being more prone to overheat than the other. I'm wondering if grilles make any difference.
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overheating
- Thread starter ak diesel driver
- Start date
My 94 Chevy never over heated until I blew the head gaskets. and I have my nose holes filled with lights. Towed 4 draft horses in a living quarters gooseneck and a 24+4 flat bed gooseneck, But I never tryed to go fast. all stock. I have a 96 stock Chevy 6.5 towed all over the country with it until it blew a rod at 150k, never over heated. My wifes 97 Chevy dosnt even get warm enough for the heater to work, it needs stats.. only drove it bob tail so far.
Woody35
Active Member
towing 5K with a very non aerodynamic and with almost full throttle accerlation on can get the gauge to start sweeping to 210. takes a while though. with normal accerlation it keeps its temperature around 198-200. but i dont think it matters
Turbine Doc
Just Another Diesel Guy
AKDD,
Want me to add to your poll, truck never overheats, & used to overheat ?
my 98 K1500 GMC truck never overheats & has never overheated even towing up to 18K# but significant mods added just pulled a rolling chasis DMax dually from Ga to Ms 460 miles no engine- trans-front clip (no I did not get pics, camera busted) last nite no IC on the ATT maybe 6K# hard rolling load; dually with no weight on front end ain't fun to tow no overheating problems, same tow 2 weekends prior Zephyr Hills Fl, to Waycross Ga no over heats there either,
In category of used to overheat, my 98 C1500 burb used to o/h but once I cleaned the rad & a/c condenser core fins FULLY (talking 4hrs labor here), no overheats since then burb has Heath waterpump-spin on clutch-plastic fan, 4" exhaust, reflash & ATT never see more than 198F H2O up to 111 mph on a 100F day.
Want me to add to your poll, truck never overheats, & used to overheat ?
my 98 K1500 GMC truck never overheats & has never overheated even towing up to 18K# but significant mods added just pulled a rolling chasis DMax dually from Ga to Ms 460 miles no engine- trans-front clip (no I did not get pics, camera busted) last nite no IC on the ATT maybe 6K# hard rolling load; dually with no weight on front end ain't fun to tow no overheating problems, same tow 2 weekends prior Zephyr Hills Fl, to Waycross Ga no over heats there either,
In category of used to overheat, my 98 C1500 burb used to o/h but once I cleaned the rad & a/c condenser core fins FULLY (talking 4hrs labor here), no overheats since then burb has Heath waterpump-spin on clutch-plastic fan, 4" exhaust, reflash & ATT never see more than 198F H2O up to 111 mph on a 100F day.
ak diesel driver
6.5 driver
my 96 has never overheated instock trim either, but it seemsto be the #1 topic of discussion. Seems to me like the GMC grils would flow a little more air
6.5coalroller
New Member
How did you go about cleaning the radiator that took 4 hours?
ak diesel driver
6.5 driver
I belive they pull it completely out of the truck put it on saw horses and soak it with scrubbing buubles or something similar and rinse with a garden hose sprayer and repeat until spotless
SmithvilleD
Active Member
I spent at least that long cleaning my truck's rad (when removed) & the AC condensor. First blowing each row w/ compressed air, then water in the reverse direction from normal front to back airflow. Even spent a bit of time carefully picking/pulling out weed seeds, etc., still well lodged in the fins. Every time you think there can't be any more crap to come out, I'd look at the water flying out the other side & and the specks of new debris still falling/showing on the pavement below.
The truck's cooling system had the mild acid flushing solution added, truck run awhile, then flushed w/ water & drained. When I flushed the radiator internals via hose when the radiator was out (at engine build time), there was still a good deal of internal crap/debris that flushed out. Same with the coolant left in the block at disassembly.
Everytime I pull an engine down & the floor of the water galley looks like that, I'm reminded why I take the time & a little expense to swap in new coolant (& use DI or RO purified water) every few years. On the vehicles I've bought new that got this simple maintenance, I've never found significant corrosion when rebuild time comes. The anticorrosion additive pkgs in coolant really do work pretty well when the system's not exposed to leaks/air & you change coolant at the recommended intervals.
Granted, my truck's a manual trans, so no additional tranny cooler heat load/additional restriction in the radiator stack, but 100 degree weather towing doesn't drive the coolant temp much more than 5-10 degrees above thermostat opening temp.
The truck's cooling system had the mild acid flushing solution added, truck run awhile, then flushed w/ water & drained. When I flushed the radiator internals via hose when the radiator was out (at engine build time), there was still a good deal of internal crap/debris that flushed out. Same with the coolant left in the block at disassembly.
Everytime I pull an engine down & the floor of the water galley looks like that, I'm reminded why I take the time & a little expense to swap in new coolant (& use DI or RO purified water) every few years. On the vehicles I've bought new that got this simple maintenance, I've never found significant corrosion when rebuild time comes. The anticorrosion additive pkgs in coolant really do work pretty well when the system's not exposed to leaks/air & you change coolant at the recommended intervals.
Granted, my truck's a manual trans, so no additional tranny cooler heat load/additional restriction in the radiator stack, but 100 degree weather towing doesn't drive the coolant temp much more than 5-10 degrees above thermostat opening temp.
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Turbine Doc
Just Another Diesel Guy
X2 above, also some "scubbing bubbles" HVAC a/c core cleaner.
JiFaire
Land Mine Finder
x2 what Tim and Smithville said... my 94 Chevy ALWAYS overheated pulling my 30' 5th wheel in the summer.. even on flat ground, it ran right warm... get into a hill and INSTANT overheat.
4 hrs pulling it out and cleaning/soaking/blowing/picking (everything SmithvilleD said), putting in a new AC Delco thermostat, new Heath SD Fan clutch, a TCC Mod, and it hasn't everheated since.
Anywhere.
In HUGE hills, pulling real heavy, going REAL slow, with HOT ambients. Like coming out of Vegas, going south to Salt Lake in Utah, from Eureka to Weaverville in N Cali, out of Penticton in BC...
With a single Tstat system and the stock waterpump.
Bill Heath helped me with some of that, and he told me that Efficient Cooling is usually a result of a lot of little things. I believe that!
4 hrs pulling it out and cleaning/soaking/blowing/picking (everything SmithvilleD said), putting in a new AC Delco thermostat, new Heath SD Fan clutch, a TCC Mod, and it hasn't everheated since.
Anywhere.
In HUGE hills, pulling real heavy, going REAL slow, with HOT ambients. Like coming out of Vegas, going south to Salt Lake in Utah, from Eureka to Weaverville in N Cali, out of Penticton in BC...
With a single Tstat system and the stock waterpump.
Bill Heath helped me with some of that, and he told me that Efficient Cooling is usually a result of a lot of little things. I believe that!
GM Guy
Manual Trans. 2WD Enthusiast
This Poll is one that is very intriguing.
ak diesel driver, i have always wondered the same thing, and i tend to agree that the GMC flows better. GMC has nothing but a badge in the center, rather than a big ol center bar that the chevys have. (this is concerning 94 and up, 92 and 93 seems to be more blocked)
ak diesel driver, i have always wondered the same thing, and i tend to agree that the GMC flows better. GMC has nothing but a badge in the center, rather than a big ol center bar that the chevys have. (this is concerning 94 and up, 92 and 93 seems to be more blocked)
Acesneights1
New Member
I'll take this a step further as far as grilles go. My Tahoe had oem work truck grille. It overheated. I changed it to the nicer grille. It overheated. My GMC overheated. Grilles make absolutley no difference as I have had all of them.
dangerousdave
1994 6.5 Suburban
Roger that, Kenny. Grilles just keep the meat from falling into the fire. Or keep the birds out of the radiator; same thing. I've been using a bug screen in front of the grille to prevent having to dismantle and clean the cooling stack. It's not real pretty, but is real easy to flick the dead buggers off daily. may even make it more aerodynamical..
I know, some guys say it hurts the air flow to the rad, but I don't overheat any more. But I do run Evans coolant. I even drilled the grille and center bracket (and moved the horn) to let more fresh air in.
I know, some guys say it hurts the air flow to the rad, but I don't overheat any more. But I do run Evans coolant. I even drilled the grille and center bracket (and moved the horn) to let more fresh air in.
SmithvilleD
Active Member
For the common bar/plate IC's, it's relevant to consider the actual surface area that air can pass thru the IC core, when looking at how much flow path surface area is needed. The point being the actual area air can flow thru the IC is somewhat less than its face/surface area. Air can only pass thru the openings in the IC face.
I suppose the % (of total radiator face area) air can flow thru the stack is a higher % of total face area (with the AC condensor/radiator), it's still gonna be less area than simply multiplying the radiator height x width = total face area.
I suppose the % (of total radiator face area) air can flow thru the stack is a higher % of total face area (with the AC condensor/radiator), it's still gonna be less area than simply multiplying the radiator height x width = total face area.
Matt Bachand
Depends on the 6.5
Kenny you never had a working fan clutch....
Acesneights1
New Member
I had a Heath Diesel Severe duty fan on the Tahoe and a Hayden severe duty(what heath uses) clutch on the GMC. No difference. The only thing I didn't get to try before selling the Tahoe was the new fan heath sent me but I doubt anything was wrong with the old one. I had found the 2000 with stock cooling system and the Hayden clutch worked slightly better but I didn't get enough time for more testing so I won't swear to it.
Odlaw
Redneck
I don't think it matters from GMC to Chevy grill. If the grill makes a difference then you have other 'issues'.
I wish I could say scrubbing bubbles worked for me but that stuff wouldn't even turn dark - spray it on and let it sit, come back 20 minutes later - nothing - rinse it off and it didn't appear to clean anything. The water that was running through the fins appeared clean...so, I had a gallon of simple green (and it really isn't a strong cleaner) in a pump sprayer, as soon as I started squirting it on, brown, nasty looking stuff started dripping out.
IMHO, to clean it properly you have to remove the bolts from the oil cooler and at least lean it back away from the condenser so you can get the matted crud out from between the two. Remove the rad and lay it on saw horses and clean from back to front(in other words, front side facing down). Spray down the condenser with some sort of cleaner and flush it with a garden hose from back to front. Use extreme caution with a pressure washer as they can bend the fins over flat.
I've never had a problem with my 6.5 overheating.
I wish I could say scrubbing bubbles worked for me but that stuff wouldn't even turn dark - spray it on and let it sit, come back 20 minutes later - nothing - rinse it off and it didn't appear to clean anything. The water that was running through the fins appeared clean...so, I had a gallon of simple green (and it really isn't a strong cleaner) in a pump sprayer, as soon as I started squirting it on, brown, nasty looking stuff started dripping out.
IMHO, to clean it properly you have to remove the bolts from the oil cooler and at least lean it back away from the condenser so you can get the matted crud out from between the two. Remove the rad and lay it on saw horses and clean from back to front(in other words, front side facing down). Spray down the condenser with some sort of cleaner and flush it with a garden hose from back to front. Use extreme caution with a pressure washer as they can bend the fins over flat.
I've never had a problem with my 6.5 overheating.