Permanent oil cooler vs thermostat

[Lt86]

(03-19-2015 11:17 PM)Deuce Cam Wrote:  I believe the technical term is idle air control valve (iacv). The unit is bolted to the bottom of the throttle body. It's easiest to remove the throttle body, and then disconnect the iacv from the throttle body. Reference pics below:

I ordered the o-ring and gasket from my dealer so next week I will be able to clean out the iacv. Thanks for the info .

Earlier this week I installed a new heater valve since my old one seized.




Since I cleaned out the heater core I expected to get a lot of heat from the blower inside the car but I find it to be only lukewarm. The heatercable only allows the valve to open for a bout 70% but even with the cable not hooked up and the vale manually opened, I'm not very impressed with the heat. The valve itself feels very hot though and the pipes to and from the heater core as well.

Anyone knows why this is?

[oldeskewltoy]

(03-21-2015 08:45 PM)Lt86 Wrote:  even with the cable not hooked up and the vale manually opened, I'm not very impressed with the heat. The valve itself feels very hot though and the pipes to and from the heater core as well.

Anyone knows why this is?

Yes... You likely have a problem closing the heater boxes blend door. There is a door inside the heater box that diverts the air over the heater core. The control cable for the blend door may be binding, or broken.


Page BE34 (Body Electric section) in the PDF AE86 service manual - http://files.aeu86.org/manuals/AE86Manual.pdf

Bottom of page BE34 is the blend door(air mix door). Move the "Temp" control back and forth and this cable should go through its range of motion... as I noted above before this edit... the cable itself is likely binding

[Lt86]

(03-23-2015 03:23 AM)oldeskewltoy Wrote:  

(03-21-2015 08:45 PM)Lt86 Wrote:  even with the cable not hooked up and the vale manually opened, I'm not very impressed with the heat. The valve itself feels very hot though and the pipes to and from the heater core as well.

Anyone knows why this is?

Yes... You likely have a problem closing the heater boxes blend door. There is a door inside the heater box that diverts the air over the heater core. The control cable for the blend door may be binding, or broken.


Page BE34 (Body Electric section) in the PDF AE86 service manual - http://files.aeu86.org/manuals/AE86Manual.pdf

Bottom of page BE34 is the blend door(air mix door). Move the "Temp" control back and forth and this cable should go through its range of motion... as I noted above before this edit... the cable itself is likely binding

Thanks! I didn't know about the door. I will check it out and hopefully this will solve the issue.

[Deuce Cam]

Is your car equipped with air conditioning?

If not you can easily remove the glove box, and then disconnect the tube leading to the heater core box (shown below, mounting screws circled in red):



At that point you should be able to see the heater core and blend door. Move the temperature knob on the hvac panel and see if the flaps are allowing air to pass through the core. You can alter the range of adjustment by moving where the sheath on the black cable is clipped in place on the heater core housing.

I would also check the hvac panel to make sure it didn't break where the cables attach. It's a somewhat common proplem due to the poor design.

If that doesn't fix the problem you might have a clogged heater core. This is all assuming your thermostat is operating correctly.

[Lt86]

(03-24-2015 12:50 AM)Deuce Cam Wrote:  Is your car equipped with air conditioning?

If not you can easily remove the glove box, and then disconnect the tube leading to the heater core box (shown below, mounting screws circled in red):

At that point you should be able to see the heater core and blend door. Move the temperature knob on the hvac panel and see if the flaps are allowing air to pass through the core. You can alter the range of adjustment by moving where the sheath on the black cable is clipped in place on the heater core housing.

I would also check the hvac panel to make sure it didn't break where the cables attach. It's a somewhat common proplem due to the poor design.

If that doesn't fix the problem you might have a clogged heater core. This is all assuming your thermostat is operating correctly.

Thanks for the tip . I don't have AC so I had the tube off in a minute. It seems the flaps are working properly. The bottom on closes entirely, the top one stays open for about half a cm unless I really pull the heater to max. heat. It might need some adjusting between the upper and bottom flap.

Anyways, I did see that the fabric is in really poor condition (no wonder after 30 years). I might pull the HVAC unit out to replace it with new cloth. BUT I don't think this should cause my problem of heaving nearly no heat.

Overview


Top flap up



Top flap down.


I already flushed my heatercore so I doubt it is clogged. Water runs through it nicely and I flushed it untill no more debri came out.




How does the thermostat affect the heat from flowing? Didn't really check the routing and I don't know it by hard at the moment. Is warm water only going to flow once the thermostat opens op?

I do have another problem with my coolant gauge. After 35 seconds idling on a cold morning (sometimes even less) the meter goes straight to the middle part of the gauge and stays there. I find this very hard to believe because there is no way the coolant could be warm so fast. Any solution or possible cause for this?

Thanks again for the help

[Bean]

have you made sure the system is free of any air? sounds to me like you got some air in there... only reason I could think of for the gauge to raise that quickly (except of being faulty itself) - although you normally would see inconsistencies as well as the air is pushed around.

[Lt86]

(03-24-2015 07:35 PM)Bean Bandit Wrote:  have you made sure the system is free of any air? sounds to me like you got some air in there... only reason I could think of for the gauge to raise that quickly (except of being faulty itself) - although you normally would see inconsistencies as well as the air is pushed around.

I bought a brand new sensor and it had this issue from the first minute. You start the car, let it idle and it almost directly rises to the normal 'hot' temperature. It doesn't go over the middle point but the temperature does seem to drop below sometimes when the engine gets cooled more.

I'm pretty sure the system is free of air. How do you get all the air out if air would get trapped behind the thermostat? I can't open the system unless it is cold.

[Deuce Cam]

The flaps in the heater core box look normal so I doubt that's your issue.

I overlooked your mention of the coolant gauge reading in the middle which is normal, although it's very strange that it reaches normal temp so fast. (It won't even do that with the heater core fully bypassed.) Also, once operating temp is reached it should stay consistent and not fluctuate (at least nothing you would see on a stock gauge). Does the coolant temp drop after getting on a higher speed motorway?

If the thermostat is stuck open the engine won't reach operating temperature, which also means very poor heater performance.

A no spill funnel kit is ideal for bleeding the coolant (shown below), but some people just tape a funnel to the filler neck. Make sure the heater valve is open all the way before starting (move to full hot on hvac panel). Then raise the coolant level via the funnel and let the engine run for at least 20 minutes. I like to raise the idle a few times to 2, 3, 4k rpm - in varying degrees - for a couple minutes during the process. Also squeeze all the soft coolant hoses periodically.

[Lt86]

(03-24-2015 08:50 PM)Deuce Cam Wrote:  The flaps in the heater core box look normal so I doubt that's your issue.

I overlooked your mention of the coolant gauge reading in the middle which is normal, although it's very strange that it reaches normal temp so fast. (It won't even do that with the heater core fully bypassed.) Also, once operating temp is reached it should stay consistent and not fluctuate (at least nothing you would see on a stock gauge). Does the coolant temp drop after getting on a higher speed motorway?

If the thermostat is stuck open the engine won't reach operating temperature, which also means very poor heater performance.

A no spill funnel kit is ideal for bleeding the coolant (shown below), but some people just tape a funnel to the filler neck. Make sure the heater valve is open all the way before starting (move to full hot on hvac panel). Then raise the coolant level via the funnel and let the engine run for at least 20 minutes. I like to raise the idle a few times to 2, 3, 4k rpm - in varying degrees - for a couple minutes during the process. Also squeeze all the soft coolant hoses periodically.

No, it usually stays right in the middle of the gauge. Only on a few occasions the temperature dropped a little bit but after a while it was just at the center of the gauge again.

I will try and check for airpockets again. Maybe my best bet is checking if the thermostat is properly working. I already changed the coolant temp. sensor, heater valve, bleed the coolant a few times, flushed the radiator, flushed the heater core,...
so I'm running out of options .

[Lt86]

Ok, I got rid of all the air in the system. Let her idle for a bit longer this time and revved up to get it all out. It seemed to work very well and I have nice hot air coming out of the vents. .

Got on to check the auxilary air valve as well. I cleaned the entire throttle body too.
Didn't get a chance to drive the car yet because it's raining but even on idle in the garage it seems to be working properly now.

At first the top coolant hose warms up, then the bottom one follows and after waiting a while the hoses running to the auxilary air valve warm up as well. So everything should be good .