My truck has started to experience some temp. problems. It so far has only happened with the plow on and the truck gets "worked" a little. By far i dont beat it i can only do about 30-35 up big hills. Twice now the temp climbs to 210, then i pull over to let it cool, i dont drive it above 210. It so far has happened when the plow is on, but i have never had a problem with temp before, so something has to be going. My first thought was thermostat. So i got one on order coming in tomorrow morning, could the water pump be going? Im sure it hasnt got a coolant flush in a long time. I dont know any suggestions??

it might be possible that with your plow in the up position, driving or whatever you may be blocking the air flow to the radiator. Not too sure if this is the issue just a thought though

yup chris is right. the plow is blocking air flow to the radiator. That's why the truck's getting a bit warm. you don't want to see it go over 210*F, as thats where expensive things tend to fail.

Just keep an eye on that temp gauge, if it creeps up to 210*F pull over, drop the plow and let her cool off, then continue on your way.

When warmer weather hits pull your rad out of the truck and hit it with scrubbing bubbles cleaner and water(not high pressure as you'll bend the fins). you'll be amazed at the crud that comes out of it. Also clean up the crud between the coolers and the A/C condenser(if the truck's got A/C).

A clean radiator is the biggest thing for our trucks cooling system.

Thats what i thought, but why for so long has it been totally fine? Just now its having problems. Ive tried driving with the plow low, angled, and straight. Ive owned it for over a year and last winter it was the greatest thing going, something must be $hiting the bed.....

Yeah i really want to clean the system, when i flush it i go all out. Is there any technique on filling it back up so you dont get air in the system? Im going to try the thermostat then on a nicer day i will flush everything. What is the capacity of the trucks coolant as so i know how much to get? The truck has always run cool 180 and never above.

Have you changed anything from last year to this year?
Winter front maybe?
Worn out fan clutch(it really roars when it kicks in fully) perhaps?
any water seeping from the water pump? Water on the inside of the hood in a spray pattern?


For the air bleeder there should be one on the thermostat crossover. My truck has the dual stats and there's one right near the stat housing.
When you flush and refill it make sure to put a 50/50 water/ethylene glycol mix in the cooling system. Pure antifreeze will not absorb heat nearly as well as a 50/50 mix will.


The factory AC Delco t-stats fail in the open position, resulting in no cab heat and a cold motor(~160 or so). I had my factory stats do this. It could be sticking closed and opening when the temps get a bit higher than normal as well.

The only change since last year is a new "used" plow cutting edge, it weighs about 75lbs. Now coolant seepage, resevior is full. Fan clutch isnt loud at all. The more i think about it i think it just really needs a flush, when it gets worked a little it just cant keep up. The truck never gets worked without the plow, driven like a grandpa. So maybe thats why, the fluid is a green with a touch of rusty brown ( truck did sit for a long time). Just been so busy lately and the temps been zero and below here the past few days. I dont want to take it to a shop, i have been screwed soo many times around here, ever since gas crunch shops have no mercy. I feel as it i will take it and they will drain and refill thats it, by my def. that isnt a flush.

The only change since last year is a new "used" plow cutting edge, it weighs about 75lbs. Now coolant seepage, resevior is full. Fan clutch isnt loud at all. The more i think about it i think it just really needs a flush, when it gets worked a little it just cant keep up. The truck never gets worked without the plow, driven like a grandpa. So maybe thats why, the fluid is a green with a touch of rusty brown ( truck did sit for a long time). Just been so busy lately and the temps been zero and below here the past few days. I dont want to take it to a shop, i have been screwed soo many times around here, ever since gas crunch shops have no mercy. I feel as it i will take it and they will drain and refill thats it, by my def. that isnt a flush.


Your better off doing the work yourself. Definitely do the scrubbing bubbles radiator clean out. That will help. The cooling system can be clean and flushed, but without a clean radiator to dissipate the heat your still going to overheat the truck.

Do you have any tips on going about the motor end of the flush? Usually i stick a garden hose in the top of the motor and then plug and unplug the bottom radiator hose, should i do that with the heater to, btw does your truck have really good heat? Start mine then let it run for 5min and i have instant heat, i love it best heater ive had.

Sounds to me like you have a typical 6.5 :D I spent the last 2 days plowing with mine and experience the exact same coolant temps. I would let it cool off at 210, but after that it wouldnt take long to climb back up again. I know they make a ton of aftermarket cooling mods for these trucks, but im not sure where i should start. Maybe the D-max fan upgrade?

I have a feeling my truck is going to have a new motor coming to it down the road. Th plugs are rusted clean off, manifolds look like they came from a different planet. Gonna send mine to a local D&W diesel repair shop next summer to get a price on trying to get the plugs out and rebuilding my injectors that im sure are also shot. What does the fan upgrade consist of?? I have never looked into the cooling aspects because my truck has ALWAYS till now run soo cool. I have regret selling all three of my previous chevys, and i have a feeling im going to with this one too, so i think im gonna rebuild, and get new sheet metal, but that is a project for after college. Im die hard chevy, except for my 89 stang, that was against my religion:rolleyes:

I have a feeling my truck is going to have a new motor coming to it down the road. Th plugs are rusted clean off, manifolds look like they came from a different planet. Gonna send mine to a local D&W diesel repair shop next summer to get a price on trying to get the plugs out and rebuilding my injectors that im sure are also shot. What does the fan upgrade consist of?? I have never looked into the cooling aspects because my truck has ALWAYS till now run soo cool. I have regret selling all three of my previous chevys, and i have a feeling im going to with this one too, so i think im gonna rebuild, and get new sheet metal, but that is a project for after college. Im die hard chevy, except for my 89 stang, that was against my religion:rolleyes:


Don't be like that just yet. I'd say try and pull out the old GPs. they may be rusted in there, but i'd say try anyways. You may be able to get an Easy-out in there or a reverse thread drill bit so the bit catches and spins the GP out. Anything is worth a try before spending all the $$$ on a rebuild that may not be needed.

I personally have tried twice, i just dont want to break something and then have a half gp hole in my head. The truck is my ONLY mode of transportaion in the winter. So im in a predicament, so i dont want it to be my problem so im going to be willing to doe out some cash to have experts do it. One plug is rotted clean off with the head. How do you not let metal filings into the cyl with an easy out? I will put a new motor in before rebuilding this one, the block is insanely rusty. I have to get you guys pics, we have the roughest salt dumped on the roads up[ here. I have to get some pics, without fender flares my truck would be able to fit 36'' tires. lol Its so bad its starting to rust above the flare, my box is solid but has dents. I have a huge driveway and my gf has a horse farm so im going to keep it and "restore" it, i love this vintage, so easy to get parts for, the only wish i have is that it had the 95 and up 60/40 split with fold down console, thats my next project!!! As of right now i dont have the money for a rebuild, thats why im afraid of breaking something

Keep on spraying the crap out of the GP's w/ PB blaster every other day, for a few weeks......you can always try the candle wax trick also.

What is the candle trick???

http://www.dieselplace.com/forum/showthread.php?t=30242&highlight=candle+wax

Check post #16.......also search candle + wax

ahhhhhh......

.. Fan clutch isnt loud at all..

BINGO !

You should hear the fan roaring at 200 degrees. I put Kennedy's fan clutch and 9 blade steel fan on mine and can crawl up a 6% grade at 8 mph and 19k combined weight and it stays on temp. Admittedly, this fan clutch comes in early and some don't like that, but, with that plow in front of your grill I would think it's the perfect match; guaranteed to suck the air all the way around that big blade. You can hear this thing come on when the thermostat opens up on a hot day. As I've mentioned in other threads I have the stock single t-stat and small pump. Of course if your radiator needs the bugs cleaned out this will only be a partial fix, but, one you probably need anyway.
Mike

[/QUOTE]The only change since last year is a new "used" plow cutting edge, it weighs about 75lbs. Now coolant seepage, resevior is full. Fan clutch isnt loud at all. The more i think about it i think it just really needs a flush, when it gets worked a little it just cant keep up. The truck never gets worked without the plow, driven like a grandpa. So maybe thats why, the fluid is a green with a touch of rusty brown ( truck did sit for a long time). Just been so busy lately and the temps been zero and below here the past few days. I dont want to take it to a shop, i have been screwed soo many times around here, ever since gas crunch shops have no mercy. I feel as it i will take it and they will drain and refill thats it, by my def. that isnt a flush.
You should be able to hear the fan start to blow hard as the engine gets hot. This is the fan clutch locking up to increase airflow. If you're not hearing this the fan clutch may be failing.

Good point i will look into the fan and clutch, hope its not too pricey, when the motor is hot i can see the fan going but it really doenst make any noise. on the last truck i flushed it was easy because it had an external tranny cooler, i dont know if my tranny cooler lines will come out of the radiator eaily?

HOLY #%$^!!!! 250 for the clutch?? The fan is a nice price 60, that will swallow my whole bonus this year!!! But ya gotta do what ya gotta do. Easy to install??? PLease let me know if others have this, i have the stock pump and single t stat, but if my pump dies i will get the dual conversion, down the road of course... I think im going to keep my truck for many years and eventually get new sheet metal and basically restore it. So i guess its a good idea...

but if my pump dies i will get the dual conversion

You should talk to Bill Heath before you go to all that trouble. I've read where he stays with the single stat and ho pump. He seems to know what he's doing :)

Check out Heaths web site http://heathdiesel.com/T/Chevy-GM/Chevy-9495/Cooling-System-Upgrades/

clutch upgrade $199. Fan comes off with four easy bolts.

Yeah, i did see that (and thanks for the advice its appreciated) but now im thinking about doing kennedys, i like the fact that it engages at an earlier temp. I love seeing my truck run 180, and i have more than enough heat in that range. Just want the truck to run the coolest it can (within reason). If anyone knows more about any experiences with the kennedy clutch please let me know, im prolly going to order it this weekend. Is there a technique to refilling the cooling system with antifreeze as so i dont get air in the system??

Do i need to put the pellets in the system??? If so where should they go i looked at other posts and said in upper rad hose, engine side or rad. side???

I got the Kennedy fan clutch....True it does engage earlier, but you'll see in the summer months it's engaged 95% of the time......A real HP bandit.......Not to mention his SD clutch is $100 more than others......
IMHO shop for severe duty fan clutch by "price" not by engagment temp......They all kick on early, thats why they are SD.

2 Cents

get parts for, the only wish i have is that it had the 95 and up 60/40 split with fold down console,

If you like the 95 look at the 97. I wish the center in mine opened for papers.

I have not had any trouble with overheating with my fisher winter front on.... I have the stock water pump and fan set up too... I flushed it out and refilled with 50/50 prestone, so far that's been all it needed.

Well flushed the system yeasturday and all went well till i cut the bottom radiator hose to install an inline katz heater. The heater wast just a little loose in the hose. I am sure the hose is ancient and expanded a little so i ordered a new one. Hopefully the heater will fit, i will make double sure to check berfore cutting. I also ordered a sd fan clutch and duramax fan conversion to try to raise the flow of air. I hope it works, i will have everything by thurs so i can install. For now im drivin a free truck so i cant fix it to quick. I got the water wetter from pepboys to put in the system, do i need the pellets?

very strange having these cooling problems this time of the year....."If you can" go about the swap 1 thing at a time to see what the real issue is/was.

Did you get the Kennedy clutch?

Yep, bought clutch and duramax conversion 9 fin fan to fit, might have a little trimming but thats all. Yeah you know something is wrong when ur truck is running hot on a 0 degree day...... I drove the truck last year to my college about a 35 min drive with the plow up and down hills, not heat issues then.... So something has to be going, its all started since i put on the 4'' exhaust, i checked to see proximity to heater lines but none near. I thinks its just a coincidence. If i do thye fan and its still overheating next will be the water pump. It overheated on me the other day without the plow too....

Well, recieved the fan and clutch today. I tried spinning the stem coming out of the clutch and it would spin freely but very hard (the unit felt cold temp. wise) If it weas cold wouldnt it spin easily?? I really dont know how fan clutches work could someone please explain??