Heater issue
12-28-2012, 09:24 AM
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Heater issue
I have a 83 toyota pickup 4X4, 22R motor. The issue I have is with the heat. I get heat until the motor reaches normal operating temperature and then I get warmish air. It is mostly cold. I have swapped the theromostat and flushed the coolant system. Any ideas what could cause this.
12-28-2012, 10:02 AM
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I believe I saw something about this on 4crawlers site. Something about needing a t-stat with two little bypass holes in it. Let me see if I can find it.
EDIT: Nevermind, that was for overheating with the heater on. Sorry!
EDIT: Nevermind, that was for overheating with the heater on. Sorry!
Last edited by Replicant; 12-28-2012 at 10:04 AM.
12-28-2012, 10:23 AM
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It sounds like you did what should be done, as far as I know, you are only left with a few options for heat issues. 1. heater core is plugged and needs replaced 2. The door operation for the vents is not fully operating. What is weird to me is that it works UNTIL it warms up. Maybe it is actually overheating and the water is becoming vapor and not circulating? Did you "burp" the cooling system after the flush? Do both the heater hoses going through the firewall (in and out) feel warm? Are you sure the temp gauge is operating as it should?
12-28-2012, 10:34 AM
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It sounds like you did what should be done, as far as I know, you are only left with a few options for heat issues. 1. heater core is plugged and needs replaced 2. The door operation for the vents is not fully operating. What is weird to me is that it works UNTIL it warms up. Maybe it is actually overheating and the water is becoming vapor and not circulating? Did you "burp" the cooling system after the flush? Do both the heater hoses going through the firewall (in and out) feel warm? Are you sure the temp gauge is operating as it should?
12-28-2012, 11:02 AM
#6
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I don't have the knowledge that some people do about how coolant flows in the engine and what all can go wrong...
Feel the hoses going in to your firewall (heater core) when you're at operating temp. Are they warm? If not, there's a clog somewhere and heat isn't getting to them. If one is hot and the other cold, probably the heater core is clogged. (with the heat on)
Do you ever really get heat? Or just warmish air? I can't bring myself to believe that you have hot heat before the engine reaches temp. And then that it gets cooler once you're at temp. Are you sure it isn't just getting warmish, then never getting any hotter?
And even worse and more presumptious of me yet, would be to assume that maybe this truck is new to you, and you just aren't used to how the heat works in these trucks? I hate to do it, but I don't know, from just your post, if you just bought this truck and expect it to work like a newer truck, or if you've had it for a while and this is a new thing happening, and it blew hot heat before.
If your coolant is otherwise circulating well (no mild overheating or other issues), and you just aren't getting real hot heat, I'd suspect the heater core. Lucky for you, the heater core in these trucks isn't much harder to change out than an oil change, compared to all the other vehicles I've seen.
It's possible there's a clog in one of the coolant galleys in the engine block or something, but I would think if that was the case, you might have overheating problems.
So...if your truck is otherwise fine, it could be the heater core.
If this truck is new to you and you've only just for the first time drove it in cold weather...could just be that it's doing more or less what it should.
My truck, once I've been driving for a while, blows HOT air. But just driving around town the other day, I was underwhelmed with the heat it was putting out. And my truck has a rebuilt engine, good radiator, new coolant, thermostat, fan clutch and heater core...
Feel the hoses going in to your firewall (heater core) when you're at operating temp. Are they warm? If not, there's a clog somewhere and heat isn't getting to them. If one is hot and the other cold, probably the heater core is clogged. (with the heat on)
Do you ever really get heat? Or just warmish air? I can't bring myself to believe that you have hot heat before the engine reaches temp. And then that it gets cooler once you're at temp. Are you sure it isn't just getting warmish, then never getting any hotter?
And even worse and more presumptious of me yet, would be to assume that maybe this truck is new to you, and you just aren't used to how the heat works in these trucks? I hate to do it, but I don't know, from just your post, if you just bought this truck and expect it to work like a newer truck, or if you've had it for a while and this is a new thing happening, and it blew hot heat before.
If your coolant is otherwise circulating well (no mild overheating or other issues), and you just aren't getting real hot heat, I'd suspect the heater core. Lucky for you, the heater core in these trucks isn't much harder to change out than an oil change, compared to all the other vehicles I've seen.
It's possible there's a clog in one of the coolant galleys in the engine block or something, but I would think if that was the case, you might have overheating problems.
So...if your truck is otherwise fine, it could be the heater core.
If this truck is new to you and you've only just for the first time drove it in cold weather...could just be that it's doing more or less what it should.
My truck, once I've been driving for a while, blows HOT air. But just driving around town the other day, I was underwhelmed with the heat it was putting out. And my truck has a rebuilt engine, good radiator, new coolant, thermostat, fan clutch and heater core...
12-28-2012, 11:21 AM
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I don't have the knowledge that some people do about how coolant flows in the engine and what all can go wrong...
Feel the hoses going in to your firewall (heater core) when you're at operating temp. Are they warm? If not, there's a clog somewhere and heat isn't getting to them. If one is hot and the other cold, probably the heater core is clogged. (with the heat on)
Do you ever really get heat? Or just warmish air? I can't bring myself to believe that you have hot heat before the engine reaches temp. And then that it gets cooler once you're at temp. Are you sure it isn't just getting warmish, then never getting any hotter?
And even worse and more presumptious of me yet, would be to assume that maybe this truck is new to you, and you just aren't used to how the heat works in these trucks? I hate to do it, but I don't know, from just your post, if you just bought this truck and expect it to work like a newer truck, or if you've had it for a while and this is a new thing happening, and it blew hot heat before.
If your coolant is otherwise circulating well (no mild overheating or other issues), and you just aren't getting real hot heat, I'd suspect the heater core. Lucky for you, the heater core in these trucks isn't much harder to change out than an oil change, compared to all the other vehicles I've seen.
It's possible there's a clog in one of the coolant galleys in the engine block or something, but I would think if that was the case, you might have overheating problems.
So...if your truck is otherwise fine, it could be the heater core.
If this truck is new to you and you've only just for the first time drove it in cold weather...could just be that it's doing more or less what it should.
My truck, once I've been driving for a while, blows HOT air. But just driving around town the other day, I was underwhelmed with the heat it was putting out. And my truck has a rebuilt engine, good radiator, new coolant, thermostat, fan clutch and heater core...
Feel the hoses going in to your firewall (heater core) when you're at operating temp. Are they warm? If not, there's a clog somewhere and heat isn't getting to them. If one is hot and the other cold, probably the heater core is clogged. (with the heat on)
Do you ever really get heat? Or just warmish air? I can't bring myself to believe that you have hot heat before the engine reaches temp. And then that it gets cooler once you're at temp. Are you sure it isn't just getting warmish, then never getting any hotter?
And even worse and more presumptious of me yet, would be to assume that maybe this truck is new to you, and you just aren't used to how the heat works in these trucks? I hate to do it, but I don't know, from just your post, if you just bought this truck and expect it to work like a newer truck, or if you've had it for a while and this is a new thing happening, and it blew hot heat before.
If your coolant is otherwise circulating well (no mild overheating or other issues), and you just aren't getting real hot heat, I'd suspect the heater core. Lucky for you, the heater core in these trucks isn't much harder to change out than an oil change, compared to all the other vehicles I've seen.
It's possible there's a clog in one of the coolant galleys in the engine block or something, but I would think if that was the case, you might have overheating problems.
So...if your truck is otherwise fine, it could be the heater core.
If this truck is new to you and you've only just for the first time drove it in cold weather...could just be that it's doing more or less what it should.
My truck, once I've been driving for a while, blows HOT air. But just driving around town the other day, I was underwhelmed with the heat it was putting out. And my truck has a rebuilt engine, good radiator, new coolant, thermostat, fan clutch and heater core...
This is my first winter with the truck. The hoses are warm at the firewall. I don't really know how hot the heat is supposed to be but I do know that at first it will melt the ice off the windshield and once the temp is up, it will not melt the ice. Thanks for the help 83.
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12-28-2012, 11:51 AM
#8
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Huh. Yeah, if it's blowing warmer air as it's heating up than it does once it's warm, I'm out of ideas...
If you have a mechanic freind or have diagnostic tools yourself, I'd just check everything to do with the cooling system. Sometimes, if we don't understand the physics of how our vehicles work, things that we would have never thought could affect one other, do. So...it would be possibly expensive to pay someone to do all this, but if you're willing, I would:
Flush heater core, just to be sure
Pressure test radiator
Leak down (compression) test on the engine
New radiator cap
Make sure there are no coolant leaks
Make sure coolant is completely free of air and is full
But I don't know what would cause it to act how it is.
Good luck!
If you have a mechanic freind or have diagnostic tools yourself, I'd just check everything to do with the cooling system. Sometimes, if we don't understand the physics of how our vehicles work, things that we would have never thought could affect one other, do. So...it would be possibly expensive to pay someone to do all this, but if you're willing, I would:
Flush heater core, just to be sure
Pressure test radiator
Leak down (compression) test on the engine
New radiator cap
Make sure there are no coolant leaks
Make sure coolant is completely free of air and is full
But I don't know what would cause it to act how it is.
Good luck!
12-28-2012, 02:17 PM
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Thanks 83. I did put a new radiator cap on. So I got home and warmed the truck up. I did notice that it is warm until the choke is off and the truck idles around 600-700 rpm. With choke on it idles around 1600-1800 rpm. Not sure where to go with this issues. I am going to try and flush the heater core. Anybody got any ideas. This has me baffled.
12-28-2012, 02:32 PM
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Higherelevation, I just noticed you are in Anchorage, SO AM I!! But I can't offer much more help, your issue is weird. I agree with 83 although. If both hoses are warm, probably means coolant is getting through the core. I can recommend a VERY good toyota shop/ guy if you need.
12-28-2012, 05:13 PM
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Higherelevation, I just noticed you are in Anchorage, SO AM I!! But I can't offer much more help, your issue is weird. I agree with 83 although. If both hoses are warm, probably means coolant is getting through the core. I can recommend a VERY good toyota shop/ guy if you need.
12-28-2012, 09:44 PM
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Okay, here's a weird thought, Did you make sure the thermostat is installed pointy side up?
Here's another one, could it be the heater hoses are collapsing internally? It might not be a bad idea to replace them. At best it works, at worst you have new hoses.
When you pull the heater core the hoses aren't that hard to pull and be sure to check the valve that opens to let the hot coolant thru the core.
Be advised, the first time I pulled my heater core it was covered with leaves and stuff.
Here's another one, could it be the heater hoses are collapsing internally? It might not be a bad idea to replace them. At best it works, at worst you have new hoses.
When you pull the heater core the hoses aren't that hard to pull and be sure to check the valve that opens to let the hot coolant thru the core.
Be advised, the first time I pulled my heater core it was covered with leaves and stuff.
12-29-2012, 03:21 AM
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sounds to me like your flaps aren't flapping.
slide the controls back and forth and listen for them opening and shutting.
are they hard to slide? the cable ends pop off sometimes, might be the flap is freewheeling
slide the controls back and forth and listen for them opening and shutting.
are they hard to slide? the cable ends pop off sometimes, might be the flap is freewheeling
01-02-2013, 07:05 PM
#14
I am having a similar problem. What I found is that the fresh air control is stuck in the open position. The control arm points to recirculate position but the flap isn't moving, just the cable flexing within the housing. I also changed the thermostat today to 192* F and while burping the system noticed that the water pump was wobbling. Ah, the fun never stops. I just got the old pump off a few minutes ago and stopped for dinner and a warm up. I am hoping that the old pump was so buggered that it was not pushing enough volume to flow the heater core, just enough to keep the motor from over heating. Never once ran too hot. Now I am in the middle of some "While I'm Here" decisions. Since the fan shroud is off, it's a good time to adjust the steering box. Nice and easy to get to right now. And since the radiator is drained, I might as well swap out the heater core too, right? And if I pull out the heater assembly, I might ought to fix that damn flapper door on the fresh air intake. You get the picture. This is my DD and has been for over 20 years. Time to fix some of these little things so I am not freezing to death on my way to Meadows. OK, break's over. Time for round two of the evening.
01-03-2013, 02:44 PM
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So i talked to a local toyota mechanic (thanks red1983), he told me to buy a toyota manufactured thermostat. I did and it worked. Thanks everyone for inputs.
01-03-2013, 03:35 PM
#16
Good to know. After changing out the water pump and thermostat, the heat has actually gotten worse. My other thought was that the core is only partly clogged so that the flow is very slow. The water would cool down and not be replenished fast enough to keep the heat up. Off to The Dalles and a visit to the dealership for an oem tstat.
01-04-2013, 06:30 AM
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sounds more like a vaccume issue to me. If it works while your on choke and engine is idled up it would be drawing vacuum from any leaking hoses. some of the heating system is vacuum
operated I am sure. would only make sense if you have a vaccume leak that once it returns to normal idle and no choke that the vacuum leak would not be enough to overcome spring tension on the HVAC system.. I would look at a vaccume schematic for your truck and see which door is being opened via vaccume and even if you tie it open until you can find the leak you would at least have heat.
operated I am sure. would only make sense if you have a vaccume leak that once it returns to normal idle and no choke that the vacuum leak would not be enough to overcome spring tension on the HVAC system.. I would look at a vaccume schematic for your truck and see which door is being opened via vaccume and even if you tie it open until you can find the leak you would at least have heat.
