ok. for starters, here is some background info on the truck; 1986 toyota pickup reg cab. 22r. rebuilt carb. previous owner had "questionable" intelligence and mechanical skills when it came to this truck. i know someone who knew the owner and got some insight. truck was bought at an auction.

anyway, this past summer i started tinkering with it and got it running right. had idle issues, sticky throttle cable, leaking rear axle, bad brakes, etc. been working all those issues out little by little. well, i decided this past week that i wanted to save some gas in my 96 chevy ex cab pickup with a 350 and drive the hilux a little. only problem, its cold and the heat doesnt work. temp gauge would never go above C. figured either i had no thermostat or it was stuck open. i pull the t-stat housing off and find i have no t-stat. went and bought one with the gasket and put it in. topped off the coolant, cranked her up and let her run idle for about 45 minutes in the driveway. temp gauge moved up to about halfway and stayed the whole time. thought i was fine. go the next morning to crank it up and drive it down the street to chick fil a, and when i got a block from my house, it overheated on me. temp gauge had slowly been creeping up. i still have no in cab heat either. even with the motor overheating, i still was freezing my bawls off inside.

so now, im going to pull off my heater core hoses and flush the heater core, flush the radiator, my valve on the firewall for the heat moves fine. at least it seems to. doesnt seem any different than on my 84 celica. now, i do get hit in the eye by the occasional leaf coming through my air vents. a friend of mine suggested that trash behind the dash is blocking the ducts causing the heat to not switch over completely.

im just wondering if anyone has any further insight or anything else that i should do at the same time while im working on this.

note: fwiw...i do belive my headgasket has been replaced before. theres a nice little bead of silicone around the edge of the motor where it squeezed out between the head and block. and knowing about the PO, its probably just instant gasket....

thanks in advance everyone. i miss driving my little truck.

 

Why dont you try flushing the coolant system first to see if that helps? Sounds like you may have a clogged up radiator and heater core. Some other tips I have: You can flush the heater core at the firewall without having to remove it. Disconnect the lines at the firewall and put the water hose to it-gently. Once the truck warms up, shut it off and take your hand and feel all over the radiator for cool spots from blockage. Check all the radiator for cool spots, top, bottom and sides. Also check your fan clutch

 

ok. will do. i was just wondering if i was missing anything since i will already be working on it.

PS...sorry about the long drawn out description. i was half asleep this morning writing it. had about 4 hours of sleep after being up for about 43 hours straight....

 

I add problems with my cooling system about a year ago and it ended up being a combination of several things, which I finally figured out. I ended up putting a new radiator and fan clutch in it.

One tip I remember someone mentioning on here is to be gentle with the pressure when you flush your heater core so not to cause a leak in it. Mine was pretty clear when I flushed it at the firewall, but others said they got a lot of gunk out of it and the heater started working afterwards.

Usually with a blocked fume in a radiator, the temperature is slower to reach overheating. Unlike a thermostat problem which usually cause overheating pretty quick.

 

Air bubble in the rad. Happens to everyone..
Start truck with rad cap off.. Slowly add coolant. Don't be afraid of it starts to bubble out. It'll go back down..
Repeat until no more bubbles or pockets of air.

 

Exactly what it is!

:wabbit2:

 

Also park front first on an incline. It helps to burp the air...

 

That it does.

 

After you try all those things, I suggest getting a radiator pressure tester and try that. it will test your entire cooling system for any leaks. It could possibly be a blown head gasket. I had the same problem with my 3.0 (i know they are notorious for that) but it would overheat and have no heat in cab. With the pressure tester you should be able to tell if it has a blown head gasket or not. Go to your local auto parts store and ask them about tool rentals because the tester can be pretty expensive. Good Luck!

 

a bad water pump will also prevent the coolant from circulating to the heatercore and radiator.

 

thanks for all the advice guys. i will definitely be checking everything out as soon as i get a chance to do it in between work and school. will let yall know what i find out...

 

Forgive me, in a rush so I didn't read all the answers. May be repeating. I had the same thing happen in my Honda. Air in the coolant. One way to fix it (how I did mine) let the vehicle sit over night. Top off coolant and start ur engine. Then keep adding coolant till it no longer bubbles down into the radiator. Put ur cap back on and go for a spin.

 

Also need to do what I haven't yet and get rid of the old metal type switching valve...

The plastic one will not corrode and bind up the valve inside it...

I didn't, and now I've got to replace a cable