eightyfive

when warmed up it runs very hot at the red line. i wouldn't let it run past that. it would take about 5 minutes to warm up depending on if i'm climbing a hill, then if i keep driving without stopping, the temp would keep climbing to the red line. when i stop driving it would slowly slowly cool back down to normal temp.

not losing coolant. no chocolate milk in oil. no oil in coolant. 195 t stat. engine has good power. new coolant, coolant flow is good as both upper and lower are firm when "warmed" up more like hot up. turning on heater will slightly only sometimes cool it a little. fan turns and when the engine is off it has a firm drag to it. when engine is running i can't stop fan with finger. radiator looks to be orginal 1980 but serviced by some radiator shop in the past.

i've seen 22rs blow head gasket and a symptom would be bubbling overflow. i am not noticing any HG symptoms on this 22r.

i am suspecting radiator however i don't want to just blow 200+ on a new one at radiatorbarn and that not be the problem. what else would cause this?

Gov't Mule

maybe the guage or sending unit is bad and you're not getting an accurate reading. not likely, but possible. could be alot of things...time to start eliminating possibilities one at a time.

DrinkUrJuice

That is really odd. It seems that it would start to overheat when sitting still and no air is flowing through the radiator to, you know, cool the coolant. That's how it has always happened to me. 90 degree day stuck in traffic and the temp gauge starts climbing.

Probably obviouse, but your radiator doesn't have a bunch of mud and grime stuck in the heat sinks does it?

83

You burped the air out of the coolant system when you put in new coolant and t-stat?

drew303

I'd use a 180f stat and make sure it has the 1/16" vapor hole

83

Technically, if the engine is functioning properly, a stock toyota oem thermostat is what it should have, but if you have good luck with something else, your experience can guide you.

Team420

Sounds like your water pump is on its way out. The fins have prolly worn down enough that it just cant push enough coolant to cool it off.... or.... You have air in the system.

dirtdobberoffroad

I also run a 180 but I drilled out the vapor hole to almost a 1/4" my temp on after market gauge reads about 185-195 depending on conditions....this may also sound stupid but the belt is not slipping is it? Or maybe sludge built up on the water pump fins? Have you ever put any kind of stop leak in it?

eightyfive

belts tight. tstat hole now drilled. no air bubbles. truck now locally drives okay (20 mile round trip) until hitting slight grade or underload, then it wants to climb to the red line. i got a line on a WORKING v6 csf 2wd 91 radiator soon, for free, so i want to rule out radiator for the next step. probably will wait for that before pulling the water pump. the pump on there now looks kinda new so i'll keep throwing all the free stuff at it first. after radiator i'll check timing and compression. truck has good power and not gulping gas so i don't know, guess i'll check those after..

thanks for the replies. oh, and no shocks in the rear and worn fronts make for an interesting ride. but, frst things first...

eightyfive

oh yea, got a better look at the back of the radiator today. i see something that looks to be rust. i'm actually hoping it's the radiator.

83

Good luck! I was having some overheating issues and would love to get a V6 radiator, but last summer I replaced my coolant, t-stat and water pump, and it's been running nice & cool so it's dropped down a few notches on the priority list.

DrinkUrJuice

Any new developments on this eightyfive? I'm really interested to hear what is causing this. Blows my mind its only happening when running on a grade. The 20R in mine has a shiny new waterpump...

caboussleman

Did you put the new radiator in? have you figured out the problem? im just wondering cause mine is does the exact same thing to a T-ee

parkerst02

my truck is doing the exact same thing so please keep informed

CAdot

iTrader: (2)

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caboussleman

thank you for the reply CAdot. I have throughly cleaned my radiator and i changed the water pump fan clutch and thermostat and its still running hot it did cool down a lil after i clean the radiator. But I'll look into a new radiator.

g3bill2

I have a '82 and was doing the same. Its got a leaky head gasket from po but sealed it with that copper/glass stuff. been ok for a few years now till a month ago got way too hot. Didnt notice cause was city driving for 6 months . I removed the 2row radiator, put 2 rubber pugs in the 1 1/4" holes filled radiator with muriatic pool acid, flushed it out maybe 4 times till the scale was all gone, maybe a total of 20 hours but at first cut the acid with about 15-20% water and full strength for the last 12 hours, nutralized with baking soda till bubbles stopped. Had 1 pin hole at bottom where there was corrosion i noticed before, soldered that. Put a new T-stat then saw a leak, Water pump was leaking also so thats new. Gave it a pressure test and was leaking from the coolant sensor next to T-stat and found a used one, then my hose clamps were the issue with 2 hose leaks, Give Me a Brake. Now its gauge shows straight up after warm up with a 190 t-stat. Wasnt too bad going up hills last weekend to mountains, never into the red but think the head gasket might be still leaking a bit? can live with adding coolant once in a while. If you guys think its good with needle in the middle with normal driving then I'm in a safe place for now ;-)

bs_funkhouser

1986 Toyota 22R Gen 3
I am having the same issue.
Overheats with any consistent RPMs when sitting still; cools a little when driving, but heats up whenever there is ANY load on it (uphill with no weight on it/not pulling anything).
The heat will continue to rise up to around 90% of the heat gauge. At that point, I pull over and vary the RPMs slowly and open the hood to let it cool, then limp it back home.
It also seems to be low on power, which makes no sense, since we have a built it to have more torque by replacing clutch and cam shaft.
There is also a small oil leak that SEAMS to be coming from the rear main seal to the
A friend rebuilt the engine from the ground up, stripped down to the engine core.
He was an SAE certified mechanic in the early 2000's and is meticulous to the point of ridiculousness.
Keep in mind, he trained to repair/build Subaru and Saab, but has since custom built several Honda, Ford, Chevy, and other vehicles. This is his first Toyota.
I, on the other hand, am NOT a mechanic, so I took notes as best as I could to understand what he did.
He took everything to the next level on this engine and spared no expense.
Additionally, he has more $ in the engine than I do, as I have promised him access to the vehicle at any time he wants, so there was no bilking for more cash going on.
Here's what was done.
- Tanked the core
- Machined all mated parts at machine shop
- Bored the old pistons out and did a custom port and polish
- Swapped cam shaft to RV cam from Toyota Shasta/Dolphin models for more torque
- New clutch - upgraded from 30 Lbs to 90 Lbs
- New pistons
- New valves
- New head gasket
- New head studs torqued to a max load of 90 ft/Lbs (studs were built for that torque level)
- New crank bearing
- New front/rear mains
- New header
- New water pump
- New fuel pump
- New heat sending unit
- New high velocity electric radiator fan (runs all of the time)
- New thermostat (OEM)
- New max flow water pump
- New radiator with 33% higher capacity than OEM
- New upper and lower radiator hoses
- New Weber 36/38 (not tuned yet)
- New fuel pump
- New EVERYTHING engine-related
- New fluids (coolant, oil)

I have had the timing checked as well.
I am at my wit's end and just want to get it FIXED!
Our next best guess is that the coolant flow is routed incorrectly.
If I understand correctly, here is how it is currently routed:
From the bottom of the radiator -> water pump -> through engine -> split some to heater core -> thermostat -> top of radiator
What should be my next move?
See pics. Did my best to follow the flow...

toy_tek

bs_funkhouser

OG Heater core, but it was flushed well.
why would a heater core overheat the entire engine?
In theory, I should be able to bypass it completely and keep the engine at optimal temp, correct?
I am at high altitude (6400 ft above sea level).
Timing is set at zero to get a baseline.
I didn't want to advance it until the heat issue is stabilized.