ive got a 85 blazer k10 that when being driven it suddenly wont go past a certain speed. the radiator fluid spills out the top of the reservoir and the inside of the cab starts getting real hot. my temperature gauge doesnt work and is always at high. im not sure if it has to do with the transmission or the radiator. Once i get to around 45mph it feels real heavy and even if i accelerate it more it wont react very much and have alot of trouble going past 50mph..

any help or advice would be appreciated thanks!

 

first thing i would do is dump the coolant and change the thermostat with a 180 degree one. If your thermostat isn't opening and your engine is overheating then if your tranny cooler goes through the radiator then your tranny is overheating as well. That is the cheaper first go around. Also check tranny fluid level and condition.

Next if still having issues then your water pump may be out. I am not sure how to check it because some new water pumps don't have the weep hole the older ones have.

It sounds like a cooling issue to me to start with. If that is it hopefully you didn't cook the tranny, provided you have a tranny cooler in the radiator.

 

Well my first word of advice is don't drive it right now. Serious damage could occur if you do.


Next, have you replaced anything? If not, check the radiator cap first. It may not be sealing.


If it's not that, have you refilled the antifreeze in it lately? If so, maybe your thermostat isn't working and needs replaced. That would explain the overflowing. It's expanding with the heat and has no where to go except out your overflow tank.


I highly doubt your transmission is causing the overheating. If it was, it would of been fried by now and needed replaced. Maybe it could have fried the 3-4 clutch pack and that's why it won't go past 45 mph easily. You can check this by pulling the dipstick of your tranny out and looking at the color and smelling it. If it's brown and smells burnt, you most likely lost the 3-4 clutch pack. If you're overheating happens during the 3-4 shift, then that might be causing the problem from the extreme friction going on in there and it has no way to cool it fast enough.


Start simple first before jumping it's the transmission. Transmissions are expensive and it'd be upsetting if you replaced your transmission to still have the overheating issue.


Thermostats can be checked by boiling water to the temp they are designed to open at and watching it open. Stick the thermostat in the water before you boil it though. Then boil the water with it in there. That'll answer if that's the issue.


Next check your radiator and make sure it's functioning. As in sealing the system properly, no leaks, and no clogs.


And check your transmission fluid please if you're concerned its affected it.


And I'd suggest while you're at it to fix your Temp. gauge. It's a very important instrument cluster gauge even though we barely look at it most the time.

 

Hey thanks for the advice! Im going to check it out today. Ill let u guys know what i find!

 

Found anything out?

 

Oh man problems after problems lol
I changed the thermostat.
Tried to turn the truck on.
It started but i couldnt let go of the accelerator or it would die on me. I warmed it up and it would still turn off as soon as i let go of it.
After a few tries, it wouldnt even crank so i got my starter tested and it had to be rebuilt.
Got it rebuilt, installed it the way it was.
I tried to turn the truck on and the exact same thing happened AGAIN.
My buddy came over n helped me out a bit and it seems to have a bad wire that connects from the small terminal on the starter to the fuse box. We messed with it and got it to turn on a couple times but it still would not stay on.
Could it be the carburetor? Or Distributor?

 

By the way, the wire we messed with has to be changed out because its stripped about 2 inches and wires are out in the open possibly touching ground

 

Keep us up to date on your issues. I am really interested in what the cause of this is.