another heater issue - I searched I promise!

[riffman12]

Not much I can think you can do there. My guess is maybe your cooling system needs flushing, might have redeposited mud into the heater core. Just a guess

hm ok thanks. I only really did one round of flushing on the core, so maybe I'll start with doing a more extensive flush, leave the CLR in there longer etc.

Then if that doesn't work I'll flush the whole system.

So strange how it worked for a week perfectly then suddenly decided to go back to its old ways!

 

[izzyandsue]

hm ok thanks. I only really did one round of flushing on the core, so maybe I'll start with doing a more extensive flush, leave the CLR in there longer etc.

Then if that doesn't work I'll flush the whole system.

So strange how it worked for a week perfectly then suddenly decided to go back to its old ways!

That week history is all I could think off that might have re-deposited gunk back in there. DON'T use CLR any longer than that, or if you are going to flush the whole system. CLR can cause more problems in the radiator. For full system flush I would only use water from the hose both back and forth.

 

[riffman12]

That week history is all I could think off that might have re-deposited gunk back in there. DON'T use CLR any longer than that, or if you are going to flush the whole system. CLR can cause more problems in the radiator. For full system flush I would only use water from the hose both back and forth.

OK cool.

Another thing I was wondering. My car has a pretty solid maintenance record from the PO, but I didn't see anything about a thermostat. Hypothetically if my tstat was stuck open could it cause these issues? Any way to check it?

 

[izzyandsue]

Good point. The open thermostat will affect the whole engine being cold and not warming up as it should. I assumed yours was working fine and it was just the heater doing the feeble job. Another clue, if it worked great for a week, it likely wasn't the thermostat. They are fairly easy to replace if you decide to go that route though.

 

[riffman12]

reviving an older thread here. I replaced my thermostat with an OEM unit (the one in the car was aftermarket)

I also flushed the entire cooling system.

Now I'm getting pretty hot air down at sea level, but the heater still seems to get weaker at altitude when I drive up to the mountains.

Can anyone think why altitude would be affecting my heater temperature?

 

[riffman12]

reviving an older thread here. I replaced my thermostat with an OEM unit (the one in the car was aftermarket)

I also flushed the entire cooling system.

Now I'm getting pretty hot air down at sea level, but the heater still seems to get weaker at altitude when I drive up to the mountains.

Can anyone think why altitude would be affecting my heater temperature?

Can anyone shed some light on this? I'm scratching my head trying to figure out how altitude would affect my heater

Wondering if it's at all related to my thread where my rig started to get pretty hot on long climbs up to the mountains?

 

[riffman12]

update to this:

I've had pretty good heat at sea level since my last core flush with CLR. It doesn't get as hot as our 2000 4runner, but it was plenty warm enough for me on cold mornings.

The last trip I went on got us up to 10,000ft+ and my heater quickly became useless like before. Now I've returned to sea level and my heater still sucks. Lukewarm at best.

I've been poking around and it looks like my heater valve is leaking, however it was a new part put in by a local shop about 6 months ago. I'm amazed it's already leaking. Not a huge leak, about a drip every 5 seconds. Here's a pic, you can kind of see the red bubble of coolant:

Note: I realize the cable is disconnected. I was testing some things. I put it back after I took the picture.

Could this be causing all my issues? Is it normal for these things to go bad this quickly? I guess all I can do it replace the valve again?

 

[izzyandsue]

Altitude for me 6000ft, and the heater is too hot still. So not sure the altitude would have anything to do with it. But I do see on the pic below your heater cable small spring clamp (rusty looking small piece of metal dangling behind valve) is not connected. There is a thread out there with how to connect and adjust. if the cable is not connected, it mus just move back and forth without opening, or fully opening the valve

 

[izzyandsue]

Found it. Shows you how to adjust for maximun A/C, you need max heat. It is the Cable Housing Clamp on the diagram that I see dangling on your picture.

Adjusting water valve to maximize A/C performance

 

[riffman12]

Found it. Shows you how to adjust for maximun A/C, you need max heat. It is the Cable Housing Clamp on the diagram that I see dangling on your picture.

Adjusting water valve to maximize A/C performance

Thanks, but I only disconnected the cable while I was testing the system. Cable operates as it should and moves the valve all the way to the stop. I've adjusted it several times in the past and even moved the valve manually to rule out the cable.

The issue at the moment is the leak from the valve. Just trying to figure out why that's happening with such a new part and if perhaps that's causing all my heater headaches (maybe letting in air?)

 

[BILT4ME]

If the valve is leaking, it is allowing the system to suck in air and have air bubbles in the system, reducing the effectiveness. Yes, it needs to be changed again. When at elevation, the internal cooling system pressure is higher and will exert more force or cause more overflow into the overflow tank. If there is a leak, it will suck in air instead of coolant because it's easier.

As far as altitude and effectiveness of the heater...... The air density at 10,000 ft is about 2/3 what it is at sea level. That means your fan has about 1/3 less air to work with per revolution.

But I think your problem is leaks.

Maybe change your radiator cap to a Toyota OEM version? (Assuming you have a Toyota radiator)

Definitely flush the entire system May as well change your PHH, rear heater hard line bypass, and other sorta PHH hoses while you're in there flushing. I used a garden hose for about 30 minutes forward and backward through every orifice I could find. Then I did distilled water 6 times, drove it to work/home for 6 days, drain each day and refill. Then the last one was with Toyota Red (don't use that now....use green), then checked it every day to make sure it stayed full.

 

[riffman12]

wanted to give an update here as it's still driving me NUTS.

Had the leaking valve replaced under warranty yesterday. Didn't change anything.

Let the car idle for about 30 minutes with the bleeder funnel today. One bubble came out. Didn't change anything.

the hoses on both sides of the heater valve are really hot, but the hard pipe that runs alongside the exhaust side of the engine and into the thermostat housing, which I believe is the outlet of the heater core, is much cooler. Lukewarm at best.

I have checked everywhere for leaks, and I see none. There is also zero loss of coolant. No coolant smell in the car, no moisture on the passenger side or anything.

All I have left is to flush the core for a third time? This seems crazy since last time I did it 4 or 5 times in each direction and used CLR.

The strangest part to me is that the heater was working very well until I went to the mountains. Now it's useless. How can altitude permanently affect the heater?

I'm so confuuuuuused. Anyone know of a good shop in the bay area that deals with this stuff? Or have any other suggestions? It's freezing outside and I'm sick of wearing a jacket while I drive

 

[Rifleman]

I'm not saying this is your problem, but you'd be surprised the amount of crap I've removed from the inside of heater/evaporator core boxes. Dog hair, human hair, dried grass, pine needles, lots of dirt, dried leaves, and even a field mouse nest. So it might be worth your time to open up your heater/evaporator core box to make sure your fins aren't plugged full of crap.

 

[riffman12]

I'm not saying this is your problem, but you'd be surprised the amount of crap I've removed from the inside of heater/evaporator core boxes. Dog hair, human hair, dried grass, pine needles, lots of dirt, dried leaves, and even a field mouse nest. So it might be worth your time to open up your heater/evaporator core box to make sure your fins aren't plugged full of crap.

hm ok I'll check that today - thanks. Wonder if that would cause the heater to run cold?

any other ideas? It seems to me like the core is just clogged with gunk again. I just don't understand how that is linked to me driving my car at altitude

 

[izzyandsue]

Spitballing here, thermostat is good? Stuck open?

 

[riffman12]

Spitballing here, thermostat is good? Stuck open?

yeah thermostat was replaced by a toyota specific mechanic about 2 months ago. Temps get up to 186 at idle here in the winter so I don't have any reason to believe it's stuck open.

 

[riffman12]

So I plan to flush my core again this Saturday. Here's what I'm thinking, curious if you guys think this makes sense:

After doing my blue fan clutch mod, my cruiser still gets 215+ on long mountain climbs like up to Donner Summit. This has always made me wonder if my radiator was a bit gunked up.

Because of this, perhaps my heater core is getting clogged by coolant flow dislodging some of the gunk in the radiator and pushing it through the system?

Then, the reason it seems to have problems at altitude is because I'm primarily running at higher RPM for long periods of time, pushing coolant faster, dislodging more gunk and eventually getting it stuck in the core?

Does this make any sense or am I actually going crazy?

 

[izzyandsue]

Makes sense based on my experience. I did my heater first without the radiator flush, worked great for our shortish winter in NC. Then did the radiator 6 months later (full flush), and a lot more crud came out of the heater the second time. So yeah, possible it is redepositing crud in there.

 

[riffman12]

Makes sense based on my experience. I did my heater first without the radiator flush, worked great for our shortish winter in NC. Then did the radiator 6 months later (full flush), and a lot more crud came out of the heater the second time. So yeah, possible it is redepositing crud in there.

yeah that's what's strange is that it keeps re-blocking after I flush it.

My buddy who's a Toyota mechanic says that's kind of early signs of a failing core, but I hope not.

 

[TheAmerican]

Im having the same issues with lukewarm (at best) heat from the dash vents. I'm convinced it's a blend door issue as very rarely it will go hot for a minute then back to barely anything. It's a good thing the rear heater is nuclear hot. Did I read somewhere the AC amplifier controlled the flap?