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22RE low temp-no heat out of heater

22K views 18 replies 14 participants last post by  Mr Stubs 
#1 · (Edited)
22RE low temp-no heat out of heater-runs cold?

I have an 85 4runner with a rebuilt 22RE. The truck runs great, I had the injectors cleaned and balanced, cleaned all the black "gue" out of the plenum and intake manifold when I pt it back together. The problem is that the temp guage barely gets abve the bottom mark above the "C". ne mechanic I talked to said "if the motor is not produing any heat(worn out) then it will not produce any hot coolant"???The motor is definitely getting warm/hot and I've tried both 180 and 190 Tstats, you can't put your hand on the top of the radiator-damn ht, after the engine warms up, so I don't think much of what he's telling me. I'm not getting any warm air out of my vents and I'm guessing I have a blocked heater core or the heater control valve that lets coolant flow through the heater valve is not opening. Shouldn't the guage be reading somewhere in the middle once it warms up? And what about no heat when I turn the heater on?
Any ideas out there?
 
#4 ·
Try backflushing the heater core. How? Pull the heater hoses at the firewall, shove a garden hose nozzle into the return line and spray water through. Once the water runs clean, run water in the inlet line and swap back and forth until the water is clear out both sides. Also, check the heater valve, make sure #1 that is is not clogged with deposits and #2 that the control cable from the dash is hooked up to it.
 
#5 · (Edited)
i think every one missed this " The problem is that the temp guage barely gets abve the bottom mark above the "C". "

i would think if the temp guage never gets above "c" then the t-stat may be stuck open. this would not allow the coolant to stay in the block long enough to reach opperating temp. this would also keep the heater from getting hot also because the coolant is never as hot as it should be. i am driving a ford ranger now with the same problem. the heater will eventualy get hot but usualy i am where i am going by then. i drove for over two hours and the temp guage never got above "c". i am thinking it is the t-stat. i bought one but have been too lazy to change it.
 
#7 ·
heater hoses reversed?no heat

2 heater hoses coming out of the firewall...1 goes to the pipe at the rear of the motor and the other to the pipe at the side of the motor(the pipe that runs up to the water pump.What is the proper routing? We replaced the motor and thinking they are reversed-no big deal, I could just swap them and see if I get heat, but can someone tell me which hose goes to which pipe? 85 4Runner 22RE.
Already tried a Toyota t-stat and an aftermarket tstat, same results.
thx
 
#8 ·
Good thought on the lines being swapped. On GM trucks that happens all the time. On those if reversed they will trap air in the core. I would imagine the same would happen on most vehicles.

My truck is a 86 with 22RE. It does take my truck a while to get warm out of the heater but once it does its hot. Cage registers normal.

Standing at front of the truck the inlet on the passenger side of the fire wall is your return. It goes to the pipe that leads up to the back of the water pump on the driver side.
 
#12 ·
Well, it's NOT the thermostat because you already said your radiator (coolant) gets hot.... so there's obviously no hot coolant getting into the heater core (clogged core / lines / reversed lines)..... and could it be that your sending unit for the temp gauge is bad?
 
#13 ·
moon1cruiser said:
I have an 85 4runner with a rebuilt 22RE. The truck runs great, I had the injectors cleaned and balanced, cleaned all the black "gue" out of the plenum and intake manifold when I pt it back together. The problem is that the temp guage barely gets abve the bottom mark above the "C". ne mechanic I talked to said "if the motor is not produing any heat(worn out) then it will not produce any hot coolant"???The motor is definitely getting warm/hot and I've tried both 180 and 190 Tstats, you can't put your hand on the top of the radiator-damn ht, after the engine warms up, so I don't think much of what he's telling me. I'm not getting any warm air out of my vents and I'm guessing I have a blocked heater core or the heater control valve that lets coolant flow through the heater valve is not opening. Shouldn't the guage be reading somewhere in the middle once it warms up? And what about no heat when I turn the heater on?
Any ideas out there?
Instead of editing your original post and confusing everybody, add new posts to update your troubleshooting.
 
#14 ·
Well igot one for ya all... We have 2 Toyota 4x4 pickups. one 87 one a 88 both 22re 5 speed. Neither one of them will get the water temp up far enough to blow warm air off the heater core. I can lay my hand on the radiator after a drive and It is not hot. We have put in about 5 thermostats from different venders, and have tested them and they work. I have got a piece of foam insulation in front of the radiator of one of them so no more than 4" of the cooling serface is showing, and it still wont get warm if its cold out (30 deg). Youcan let them idle for an hour and if its close to freezing it might thaw out the windows, but if its 20's or less forget it. This is not a new problem its been going on for years, and I have not found the solution. Both run well, but are high miles. I still find it hard to believe but it is NOT the thermostat. Neither one uses water, they just refuse to get hot. The only time I get het is plowing snow from a parking lot, as its a smaller lot, and I am in reverse alot. Anybody ever come across this proble and have found a fix? And dont even try to tell me is a thermostat issue. It aint.
 
#15 ·
I have a real similar issue, my motor ran at normal temp, heater put out good heat. I had a radiator hose started leaking motor overheated. After that head gasket blew, got head repaired installed new thermostat during all that work after that heat hand barely moved above C, plus no heat discharge. Thought I got a bad thermostat so tried 2 different ones, no difference. Gave up at that time, then over the next year the heat would gradually get to where it would get to normal temp. Until I changed water pump & thermostat last week, now I am back to a cold truck again. Has anyone ever figured this out?
 
#16 ·
sounds like air or blockage in the heater core or a bad heater switch on the line. easy enough to check, drain down some coolant and take the lines apart that service the heater core circuit, you should be able to see if the ball valve is working properly, if the lines are full of shit, and with some gentle air pressure (once the water is blown out) if the heater core itself is blocked.


replace whatever one is causing the issue
 
#19 ·
In my experience, a vehicle not heating up.

Tstat
Fan always on
Low coolant, air pocket.
Yes to all of this.

The stock clutch fan shouldnt be the issue staying on.

New or used T stats? You can check them by putting them in a pot of boiling water.

I have had air pocket issues before. My fix has always been adding a T at the heater core inlet/outlet hose. The ones at the firewall right next to the heater control valve. This is the highest spot of the cooling system. If the T has a threaded end for a garden hose, it can be used to flush the system/heater core also.
 
#18 ·
i've had the ball valves break and get brittle, i've seen the actuator cables get stuck and jammed, but yeah...most common is "i already bled it" followed by "it was low on coolant"
 
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