Heater and Low Idle Issue

[imryannn]

I have searched and searched and tried everything I could find on the internet for why my heater is not hot.
I did a multiple coolant flushes today to see if that was the issue, the coolant or lack there of in the radiator was rusty. I used blue devil coolant flush and distilled water, let it run until it was at operating temperature with the heater on full blast. At this point the heater was working perfectly and I thought I had fixed the problem. After letting it cool back down and draining it, and flushing it out with water as best I could, refilling it with coolant and distilled water. I drove it around to get it back to operating temperature and make sure everything was working normally, the heater again never got hot. A little warmer than it was prior to the flush but no where near as hot as it was when I had the blue devil in it.
Checked the cables and assembly under the passenger dash, everything looks like it is functioning normally.
SIDE NOTE: my lever for the temperature is extremely hard to move hot from the cold side.

Second issue, not related to the first but I figured I wouldn't make yet another thread, my idle is barely over 500 RPM and feels like I'm about to stall every time I come to a stop light.
I cleaned my MAF sensor today with no change in idle, also cleaned out the throttle body, also with no change. I didn't get to the IAC because it was getting dark and cold tonight.

Any advice or things to check for either or both issues would be greatly appreciated. Starting to get frustrated here

 

[reelamin]

I have searched and searched and tried everything I could find on the internet for why my heater is not hot.
appreciated. Starting to get frustrated here

Did you read these threads? Lots of information on your heater.

http://www.toyota-4runner.org/gsear...ORID:9&ie=ISO-8859-1&q=3rd+gen+heater+problem

 

[imryannn]

Did you read these threads? Lots of information on your heater.

http://www.toyota-4runner.org/gsear...ORID:9&ie=ISO-8859-1&q=3rd+gen+heater+problem

Yes I have read a bunch of those, I am going to try to flush out the heater core alone through the inlet and outlet on the firewall, hopefully that will help. If not it might just being going to a shop to have the heater core replace because I don't know if I have the patience to pull the entire dash apart in my parking spot at my apartment

Anyone have any ideas on the low idle? When I search for information I just get a lot of high idle threads...

 

[Harleydoc]

If it is hard to move more then likely it is the valve under the hood you can try to turn it by hand under the hood and see if you get some heat then or not


Sent from my iPhone using Tapatalk Pro

 

[nissanh]

Flushing the heater core alone is not enough. You have to flush the engine block, rear heater line (if applicable) and a new radiator. One you know there is absolutely no particles to clog the heater core the heater should work normal. Glad you have manual controls so this eliminates the actuator.

I usually attach 5/8 clear hoses to the in and out of the heater core near the valve (not directly to the aluminum lines on the core: don't want to damage it). Run water on both directions with the garden hose. Then flush it with distilled water. Did the same for the engine block with thermostat removed and flush. Finally added the coolant.

 

[catrains]

you did fix the heater problem by flushing out the heater core. also you got heat. then you say rusted coolant.

so when you ran it the second time the heater core plugged up again. the debris in the system if bad like you say will require several coolant system flushes. also using chemicals to loosen up the mess.

draining radiator means everything.. radiator is not a complete drain. also blow out the heater core after you flush it see if its with crap in the bucket when you do it.

people living in warm areas do not use the proper % of antifreeze to distilled water.

if you just drain radiator and not the engine and add 50% antifreeze pre-mix that would be a low % of antifreeze..

I use 60% antifreeze that provides the most protection from corrosion and water pump ..also it boils at a higher temp.

T stat must be removed when doing the flushing..

 

[imryannn]

UPDATE: So I drive around today for a couple hours, heater started working BETTER, not real hot or anything.

I was planning on doing anothe flush in a couple weeks regardless if everything starts working properly.
At that point I am going to do flush out the entire system as best I can like I did yesterday, then flush out the heater core, back flushing back and forth through the inlet and the outlet because I'm sure the flush I didn't yesterday didn't get most of it out. Drain through the block and thermostat, flush it again with distilled water and then get Toyota red coolant.

Do any of you guys have any cooling system flush chemicals that have worked well in your experiences. I used blue devils yesterday and am wondering if there is anything better? Not that this didn't work well...

Thanks for all the replies

 

[TheDurk]

you did fix the heater problem by flushing out the heater core. also you got heat. then you say rusted coolant.

so when you ran it the second time the heater core plugged up again. the debris in the system if bad like you say will require several coolant system flushes. also using chemicals to loosen up the mess.

draining radiator means everything.. radiator is not a complete drain. also blow out the heater core after you flush it see if its with crap in the bucket when you do it.

people living in warm areas do not use the proper % of antifreeze to distilled water.

if you just drain radiator and not the engine and add 50% antifreeze pre-mix that would be a low % of antifreeze..

I use 60% antifreeze that provides the most protection from corrosion and water pump ..also it boils at a higher temp.

T stat must be removed when doing the flushing..

You really don't want to go over the 50% ratio unless you live in the Arctic. While anti-freeze and anti-boil performance is improves, the coolant efficiency declines, as H2O has a better ability to absorb heat than coolant:

When we’re on the hot end of the temperature range, the much more important value in the cooling system is what’s called the specific heat capacity. The heat capacity is basically how much heat energy the coolant can carry out of the engine and to the radiator. As far as carrying heat goes, water does a really good job. It’s actually one of the most effective coolants that could possibly be used. The specific heat capacity of ethylene glycol is only about 65% of water at the temperatures seen in a cooling system. That means that to cool the engine by one degree, you would need about 50% more of it than straight water. So even though you could use pure antifreeze as a coolant, or any other liquid for that matter, you would need a bigger radiator and more robust cooling system compared to one that used straight water. Here is what happens to heat capacity as our coolant mixture changes:

https://hellafunctional.com/?p=629

Freezing point of 50/50 is -40° (on both scales, F or C). You want a little margin, but still, you have to be in a really cold place to need more than that.

 

[imryannn]

I forgot to add to symptoms to the low idle issue, it is only when it's in gear whether it's park or reverse it idles barely over 500 rpm...in neutral or park it idles at about 700 or so which feels a lot better

 

[JBDaddy]

Probably not related to the idle issue, but in a past vehicle experiencing poor heat output I ended up replacing the thermostat to fix the problem.

I haven't seen it mentioned yet, wanted to throw out the idea - it was a cheaper fix than doing the heater core so I tried it first, and it worked.

 

[catrains]

your chart does show the BTU diff of 50-60% NIL ..that is not a factor that doesn't help much on cooling with a properly maintained system. what does effect proper engine cooling is the control of corrosion. also the additives in the antifreeze for pump lube.

50 % is the min .. 65% is the max. most with engines that do have corrosion issues use the max of 65%.

when the corrosion starts working on the metal the efficiency of cooling drops. then what owners do is drop the % down to 30 -40% to gain extra cooling ability with the damaged system this only increases the damage then a new radiator and other parts like pump fins disappearing LOL.. it is real... no water pump fins ...

I never had any over heating using the 60%. also my water pump and coolant system/radiator no corrosion well over 10 years old.

I have to replace my T stats because the engine temp is too low ..

when the coolant boils the water pump cannot pump the bubbles.

 

[Spunk]

I forgot to add to symptoms to the low idle issue, it is only when it's in gear whether it's park or reverse it idles barely over 500 rpm...in neutral or park it idles at about 700 or so which feels a lot better

Fixed the same problem, had it for several months. Cleaning MAF and other stuff did not fix, just temporarily alleviate this particular flavor of problem. .
Replace your spark plugs. They may be a bit outside of the regular engine tune window. We are supposed to replace our plugs every 30K-Mine were at 75K when I replaced them.

 

[alumarine]

Probably not related to the idle issue, but in a past vehicle experiencing poor heat output I ended up replacing the thermostat to fix the problem.

I haven't seen it mentioned yet, wanted to throw out the idea - it was a cheaper fix than doing the heater core so I tried it first, and it worked.

Good question.
OP hasn't mentioned if he did that or not.

Poor heat is usually not the heater core.
They tend to leak before they clog, although there are exceptions.

Although I live where everyone uses 50-60% antifreeze.