New 2000 LC Has issues Help (1 Viewer)

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Just purchased 2000 LC, has issues help

Hello all!

I just picked up a 2000 LC with 60,000 miles on it. Truck is in great condition execpt for a couple little things...

What I thought would be an easy fix is getting frustrating fast. The heater doesn't seem to put out very much heat.

I've now been to two toyota dealers. One told me it was fine and nothing was wrong with it. The other thought flushing the cooling system would work. Then when that didn't, they put in a new thermostat in the engine (not the heater). Still no good!

My guess is that it's not getting enough hot water in the heater core. It warms up, but takes about 20-30 minutes to get there. I have to run it in recirc mode and after about 20 minutes I start to get warm air out. It will never blow HOT air. In the fresh air mode its just about worthless, the faster you drive the worse it is.

Is there a heater valve that controls water flow? Should I try to flush the heater core from the engine bay on the firewall?

Any ideas would help.
 
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The heater switch typically controls a valve that opens and allows hot coolant to flow through the heater core and return to the block. If you engine is warming up properly (is it?), it wouldn't be the thermostat. I'd suspect either the heater valve isn't opening up/stuck, maybe the electronic switch isn't operating properly, or the core is clogged...something is impeding the flow.
 
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That is what I was thinking. The truck warms up fast and runs in the middle of the temp gauge without doing anything odd.

Can you tell me how to R&R the valve? I'm worried that it's very very hard to get at.

What you think about trying to flush the heater core from inside the engine bay. I see two pipes going into the cab through the firewall that I would think could be flushed.
 
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Looking in the FSM I don't see any valve that opens to the heater core. It looks like the heater core is always hot and air from the heater core is mixed with cooler air for different heat levels.

I would inspect the Air Mix Servomotor and the related switches. FSM AC-29
 
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NMuz is on it....
Also, if the cabin temp is 'close' to desired , the heat will be lukewarm.
Trying to 'fake it' may not work either...A/C puter is pretty smart (or stupid...point of view)

Fake it: Cabin temp is comfortable, outside temp is comfortable...set thermostat to "bake"...
may not get the bessimer furnace blast like in the 'old' days....
 
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I looked up under the dash and moved the temp setting dial. It seems like all the servos down there are working fine. Looks pretty complex though. It does flip levers and arms up under the PS foot well as I change the dial for the tempature.

I'm thinking that the heater core is not getting enough water or is semi plugged. I will try the flush out.
 
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Soggy,

Even set on the bake setting it doesn't put out much heat. With engine hot, cabin cold it still blows lukewarm air out.
 
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Yeah, you definitely got an issue. If I put mine on the hottest setting I could bake brownies in that thing. When I removed some of the fake wood trim, I used the advice of turning on the heater for about 15 minutes before I started to loosen up the adhesive. This worked like a charm, it was like a sauna in there.
 
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UPDATE: No water from the engine block!

I put a water hose on both sides of the heater core and I get full garden hose flow through the heater core. It does not seem to be blocked!

What i find is little to no water flowing from the block into the heater system. I hooked a hose to the outlet from the top of the engine block and ran the hose into a gallon milk jug.

With the engine at idle I get ZERO water flow. Only when the engine is up over 3000 RPMs does hot water start to flow well. I still only got about 1/2 gallon after 3-4 minutes of this. It seemed real frothy and sputtered out like it was trying to push air around.

Any thoughts?
 
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Update II

Just got the truck back from another Toyota wrench.

The big shock is that he thinks it’s working correctly!

According to him I will only get high levels of heat when the fan is in the auto mode. All this time I have been using it in the manual mode. He insisted that it was even mentioned in the service manuals and talked about a door servo that is activated in the “auto” mode. This door forces all the air through the heater core when the fan is set on “auto” mode therefore allowing the higher heat levels when needed.

Can this be true? It did heat very well in “auto” mode on the drive home. The real test is the morning drive though.

It does not explain anything about this in the owner’s manual.
 
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I dont buy it - regardless of outside temp, or cabin temp, when my engine is warm the heater will blow so hot you cannot take it - using manual or auto mode...to me thats like saying the a/c wont blow cold unless using auto mode - which isnt true either....
 
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I don't buy it, either. I've never driven a Toyota that didn't output roasting heat. Do you know exactly where the heater valve is? I don't think it would be silt clogging the flow (I have had the block drain hole silt up in my old mini from the PO using green coolant+tap water. I removed the bolt and barely any coolant came out. Upon inserting a coat hanger into there and jiggling it around, a gush of coolant rushed out). But that drain is on the bottom while the heater outlet from the engine is near the rear top. I'd suspect that the valve to control the heater is in the block just before the hose (check the FSM), and that it's electronically actuated and faulty. Could you remove the valve and check it? Also check the harness up to the valve, just in case.
 
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Jim,

I don't think there is a heater valve on this truck. I think it's all done with mixing doors to direct airflow. Also the heater core flows great and in auto mode makes great heat. So it seems it gets lots of water when in auto mode.

I just code testing instructions from another member so I will try that this evening.
 
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Sounds like a bad answer from the tech. I can roast weenies on the output from my heater in the manually selected position.

After warm up in the morning are the lines into the heater core even hot?

When you did your heater-core flow-test you are sure it was the front core and not the rear heater core ?

Has your truck been run with any coolant other than the Toyota Red?
 
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NMuzj100 said:
Sounds like a bad answer from the tech. I can roast weenies on the output from my heater in the manually selected position.


After warm up in the morning are the lines into the heater core even hot?

---YES, They get very hot.

When you did your heater-core flow-test you are sure it was the front core and not the rear heater core ?

---Well i'm pretty sure, as it looks like the rear core lines just Tee off and go down under the firewall. I flushed the ones going direct into the firewall towards the dash.

Has your truck been run with any coolant other than the Toyota Red?
---???? I dont' know what has been going on the last 5 years.
 
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sprocket3 said:
---???? I dont' know what has been going on the last 5 years.
The Toyota coolant when combined with others and a toyota coolant system has been known to cause silting problems. I think that is highly unlikely to be the cause of your problem. .

Looking at my truck today it is clear there is no valve like Jim is talking about and the heater core is always hot. You have good flow through the core and the lines are hot after warm up. I still think the most likely place for the problem to be is the is the "Front Air Mix Damper Control " (FAMDC)

The FSM lists following suspect areas for a symptom of "NO WARM AIR COMES OUT"
1. The FAMDC position sensor circuit DI-659
2. THE FAMDC servomotor circuit DI-688
3-5 are the temp sensors (probably not involved since your heater doesn't work at full heat)
6. A/C amplifier

The A/C panel can do a self diagnosis. DI-620

1. Turn ignition switch to on while holding down the A/C and Recirc/Fresh switches.
2. All the indicators should flash on and off at 1 second intervals.
3. Any malfunction will be indicated by the trouble area's light blinking. A table to translate the lights to a trouble spot is on DI-624 or post it here and I'll look it up.

I did this just now on my truck. Very easy. And came back with the DEFROST and REAR WINDOW DEFROST SWITCH. This indicates a SOLAR SENSOR malfunction (sensor covered with a windshield shade).

If the REAR WINDOW DEFOGGER SWITCH and the RECIRC switch are lit that indicates the FAMDC PS.

If REAR WINDOW FOGGER and the POSITION 1 on the fan speed dial are lit then it idicates the position sensor or servo motor.
 
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Joined
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Ok.

I had a chance to run the self check today and this is what I find for trouble codes.

1) Rear Fan
2) M1
3) Def
4) RdDef

I'm curious to know if either of the toyota wrenches that looked at my truck did this simple check. It would seems there are some problems with the system still.

So it looks like there is a problem with one of the "the position sensor or servo motor"... Do you know which one, and how much trouble it is to R&R.

Any idea on what the other codes mean?

Thanks for all you help with this.
 
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Does two lights blinking at the same time indicate one code. I think that ReDef and M1 blink together sort of in combo. If so I should repost what I found.

I did it again this morning and it seems like Three different erros code combos. I had no pen, so didn't write anything down.

I'll try again after pulling the fuse.
 
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Yes two lights blinking together indicate the code. If you press the A/C button it should slow the codes down to make multiple codes easier to read (I think anyway, sometimes the english in the FSM is :confused: )

Or if you press the A/C button it will give you one code then press again for the next code. (Not sure what they mean by stepped operation)

I'm not sure if you should pull the fuse before getting all the codes down as that will erase the codes. Some of the codes take 8.5 minutes of failed operation to set a code. From your post it looks like you have an FSM, yes?

As far as R&R I have no idea.
 
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