1994 Camry no heat!!! Help

[dhutzn]

Hello to all from newbie
I have a 1994 Camry with 3.0. I have done the following and still have luke warm heat if any. New thermostat, new radiator, new water pump , water lines bled, heater core replaced, checked heat valve for correct operation, plenty of water. I checked the lines going to the heater radiator and the temp is over 105 degrees. My fan works just fine and I am at a dead end. I read somewhere else something about a heater fuse. Does this apply to this car/engine? Where is this misterious fuse located? I looked under the hood and none of those fuses say heater. Help please as I live in Minnesota and heat would be a benefit!!

[Dave's]

Heater fuse s/b just for the blower fan. If it's working then forget it. 105 degrees is way too cold. I would guess 195 would be closer to what you s/b seeing. Remember, you're body temp is nearly 99 so you need some real heat to feel it. A bit over 100 will feel lukewarm at best. But then guess you're measuring on the outside of the hoses so I wouldn't know exactly what you should see if that's what you're doing.

[CamBOT]

Wheres your engine Temp indicator at? During - 20 Deg Celcius weather mine wont climb past 1/4.

I was using 10W30 Sythetic oil at that time, now I switched to 5W and it warms to half and the heat is better.

[dhutzn]

I took the car out for another drive today and now have heat. The only thing I can think of is that the heat control valve was stuck and the linkage attached to the cable was sliding over the plastic on the valve itself. Thank you for your input.

[cruisn76]

Originally Posted by CamBOT

Wheres your engine Temp indicator at? During - 20 Deg Celcius weather mine wont climb past 1/4.

I was using 10W30 Sythetic oil at that time, now I switched to 5W and it warms to half and the heat is better.

Same thing. I am running 10w30 non synthetic, and my heat is hot but not hot enough. CAMBOT have you changed ur themostat? I am thinking about changing it if it would increase my heat.

[JustinC25]

I'm having a simillar issue with my '95. It has a 5S-FE.
New W/P, New Aluminum radiator, flushed the heater core and it was clean, New T-stat,
Checked operation of the heater valve on the firewall.

Basically the issue is that when it is really cold out, like 20 F or less the car has little to poor heat at idle. (Like when waiting at a light.) I've actually seen the temp gague move a little at a light when it is below zero.

2k rpm and up it is fine. My only theory at this point is that it has to be the radiator.
As stated earlier the new radiator is aluminum, and the original was copper.
I think it is too efficient for the cooling system, and it is loosing heat at idle, At driving speed it is fine.

I first noticed this problem the winter after I replaced the radiator. So I started with flushing the heater core, and checking the heater valve, then replacing the T-Stat, and waterpump when I did the t-belt.

So that is where I'm at.

Oh yeah, there is no air in the system, and it has plenty of coolant.

[Stillrunning]

Originally Posted by JustinC25

My only theory at this point is that it has to be the radiator. I think it is too efficient for the cooling system, and it is loosing heat at idle,

That's what the T-stat is for, to maintain proper water temp, no matter the rad material.

Under drive pulley? Other possibility is air control doors that adjust off dash temp control switch. Maybe that T-stat is not working properly.

[bcp477]

I recently began experiencing this sort of issue, as evidenced by the engine temp. indicator not getting up to the the "normal" range, unless idling (or sitting at traffic lights, etc.), for a while. Heat inside the cabin is in direct correlation to this - if the indicator needle is down, the heated air from the vents is cooler, etc. Further, after sitting still, then driving off, the needle will quickly go down to the bottom of the scale, the more so as speed increases. My radiator, thermostat, water pump, etc. are fine, as are the various electronic bits associated with the system. The only thing that has changed is that recently I removed the underhood insulator "blanket" (it was filthy and torn)....and the metal spray-shield from the bottom of the car....and discarded them. So, I believe that the issue is due, believe it or not, to greater airflow inside the engine compartment and less heat retention. It seems far-fetched to me, but that is really the only possibility. I intend to try a home-made partial radiator blanket, to see if this helps the situation a bit. My engine certainly does warm up - it is not a stuck thermostat (that is the first thing I checked). It is possible that the increased airflow is acting on the temperature sending unit itself, except that the flow of heat into the cabin also varies with the position of the needle. So, I have concluded that the issue is increased airflow..... resulting in "over-cooling".

[Dave's]

Again, a T-stat is all about maintaining the correct operating temp. It should be closed when the engine is cold and begin to open as the temp increases. It should be full open when and if the correct temp is reached and will begin to close if the temp begins to drop too low. Thus if your cooling system is very efficient the T-stat might open some and close some back and forth as needed. T-stats tend to fail in one of three ways. If it sticks closed you will most likely have your engine overheat. If it sticks full open you probably won't reach normal operating temp which can actually cause other problems besides lack of heat in winter. The other way they can fail is for the spring to weaken. I've had this happen and I discovered it by heating it in water with a candy thermometer only to find it was fully open at 140 instead of the 195 stamped on it. Needless to say, I didn't have enough heat to keep the windshield clear or us warm. FWIW!