So i went out and let it run, it is about 47f right now. i let it idle at temp and did not get great heat. I also looked under the dash, played with the doors and they all look good with no issues. I am starting to think the cold winter temps are disguising the true problem. I think maybe the water pump is not pushing enough coolant, therefor low flow to and through heater core, if it were summer if this were to be the case i would have heating problems.
Seems like i do not get great heat until the thermostat is open and coolant can flow more freely. What do you think of that?
The heating will most likely work better when the thermostat is open since the coolant flow is restricted until then. The heater core won’t have a circulating supply of hot water until then.
I doubt there is a problem with the water pump and suspect the trouble is due to a clogged heater core. Especially if the vehicle is older than 10 years. It would be nice to know what the temperature of the water is coming from the engine into the radiator. If the thermostat is working correctly it should be near the temperature rating of the thermostat.
The temp of the coolant goes up to the 180 range, this is with one of the laser units and right on the them housing. I just drove home, temp was 32-35f heat worked ok. I pulled into the garage and put my hand on all hoses. Top rad hose was hot, bottom was a little warm, input to core nice and hot, output warm, .
The other day when i replaced the therm, i left the cap of the rad, i pulled the output of the core off, at idle i had a trickle, if i rap it to 1800 i had good flow on the output.
If the thermostat you put in was a 180 degr thermostat then the temp is obviously right. Perhaps you used to have something like a 195 degr thermostat and replaced with a 180 and now you think the heat is not great but just by comparison to what you’re used to?
Just to clarify - earlier you said you had also pulled the inlet to the core and it only trickled as well, yes? That’s what makes it sound like a circulation problem to me. On the other hand, if the inlet is a gusher and the outlet is a trickle - well, that speaks for itself.
true on the last part, at idle trickle in trickle out, 1800rpm good flow in and out.
As soon as the kiddos are in bed i am back at it. Not sure where to go with it but?
I bought this vehicle 4 weeks ago so i do not know what the history is, i read in forums that the heaters a very good in these rigs. Nice vehicle, very well taken care of, looks like it has 20,000 miles on it, it has 140,000 Runs like a champ. Love it
Ran BG cleaner through it, then back flushed. Then took it to the car wash, bypassed line and flushed both directions, then when i did the thermostat, i did it again. This was all in a weeks times. I never saw anything nasty come out
I may pull the manifold where the top hose, heater input hose for the core and the throttle body heat is all fed from off to see if i see any corrosion, this might tell me something about the condition of the cor and other things.
So i pulled the input heater hose off, manifold of the engine as stated above, all these hoses and the manifold look good, no corrosion. I put an extension on the input heater hose with the engine running i had a trickle, so this rules out everything else out.
We have little to know flow on idle from the engine to the core.
How about the water pump impeller blades? I don’t know how old the pump is but any chance they are worn down so they are not creating a flow through the engine & heater core?
Also maybe the one of the radiator hoses came unlaminated from the inside and is blocking the coolant flow; may look great on the outside, but the flow is being blocked inside by a hose flap.
Long shots but ya never know about factory defects.
I suspect the low flow at idle is normal. There may be a blockage inside the engine block but you stated that the flow looks okay when the engine is running at normal speed so that doesn’t seem to be the problem.
ran to Leadville tonight,10,200ft, it was 15F, heater worked great on the way up. Went in for 30 mins to grab a bite, came back out got on the road, took 15 min to warm back up but was great when it did. Tried to get my hand down where the fresh air intake is, i felt a little bit of cold air coming in but the heater worked great. Not sure, most of the time when it works it works great, it just takes a long time to get it that way. Seems as though when the thermostat opens we have nice heat, just takes a while to get that to happen.
Well i have the controls on recirc but i felt up around the blower at 65 mph and 15f and felt a little cold air, maybe i have some air leakage, hard to find driving down the road though, LOL
According to the 2006 Toyota RAV4 service manual, all you have to do is fill the reservoir with coolant up to the neck, then squeeze the upper and lower radiator hoses to purge the air from the system.
If might be diffrent for the 09 model but I’d give it a try.
Did test the new thermostat before you put in? If not you might have been unluckly enough to get a bad one.
Do you have access to a rad kit. With this tool you can pull a vacuum on the system at the radiator. Pulling a vacuum checking to see if it holds will eliminate any air leaks posters are concerned about. You mentioned using the BG cleaning chemical. BG has a rad tool that pulls the vacuum and uses that vacuum to pull in the coolant to ensure no air bubbles.
I am starting to believe that it is the heater core, I can blow thru it, i can run water thru it but i dont think it is flowing thru all of the viens. When i start building pressure and the thermostat opens, i get more flow and better heat.
I have refused to believe this till now but i find no other explanation.
I used the funnel technique, worked great. Could still be air but i sure do not think so. I filled the output core line with coolant, then filled core and then put the input hose on.
The heater will eventually warm up but it takes a while, i think the heat and pressure along with more flow with the therm open is expanding the core enough to flow.