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moses again, Man i STILL have no heat!

Posted: December 24th, 2005, 1:14 am
by MOSES
ive been suffering the cold because i have only 3 % heat inside the car.

heres a list of is and isnt's for those willing to help.

not air locked
new thermo
new belts
new pump
new fluid
fans work fiine
fresh air intake and recirculate butten works
air mixture cable works
rad seems 100%
heater core free flowing, even before a backward flush
i would turn the fan off for a few secs the turn it on, i get a little heat the it gets cold.
Im getting water restriction from somewhere, i think.
any body please help me, im freezing my nips off here, thanks

Posted: December 24th, 2005, 2:19 am
by XxantwawnxX
wow..seems liek you went trhough everything....i dont know man.

Posted: December 24th, 2005, 3:27 am
by 93_mx3_gs
might have air in the heater core possibly.

Posted: December 24th, 2005, 4:16 am
by jschrauwen
No mention of replaced thermostat unless when you say "replaced thermo" it means that or perhaps the thermosensor - don't know which.
Before and after engine is warmed up feel the return line hoses from the heater core and the return line from the thermostat to the rad. Do they feel that there's pressure inside and/or do they collapse fairly easily? As engine warms up, is it easily discernable to notice when the thermostat opens and then lets the hotter coolant past the thermostat to the rad? Confirm that there is passive heat always coming from the heater core without the fan turned on. And only when fan is turned on it begins to get quite cold. If that's the case than if you have A/C, then for some reason the main A/C switch is stuck on or unknowingly is on and is only engaged when the fan is turned on. That's a real wild guess, meaning unlikely but just a shot in the dark. Heat select slider or electric switch is functioning properly?

Posted: December 24th, 2005, 8:28 pm
by MOSES
everything on the dash is in working order, all cables and buttens.
it seems to me that there is sufficiant flow to the core, a-- soon as i turn the fan on i get warm air for 3 secs. then cold from there, where can there be any blockage?

what the beep is on da go?

Posted: December 24th, 2005, 8:59 pm
by jschrauwen
MOSES wrote:everything on the dash is in working order, all cables and buttens. Great

it seems to me that there is sufficiant flow to the core,
This meaning that you physically felt the coolant lines to the core, before and after engine was warmed up?

a-- soon as i turn the fan on i get warm air for 3 secs. then cold from there, where can there be any blockage?
If there indeed is one, perhaps right in the core itself. I already asked about the return line check yet you made no mention of that. Is there hot coolant leaving the heater core after the engine is warmed up and also after you turn the fan switch on?
I also asked about verifying if the A/C is kicking on? The A/C switch can be turned on or faulty and stuck in a closed (turned on) status but will not engage the compressor until the fan switch is turned on. Is the compressor engaging when you turn on the fan?
Only other wild guess would be that at the time of you changing your water pump, a large piece(s) of scale may have broken free and lodged in the smaller heater core tubing. But then again, if you had mentioned what the nature of the heater core return line was, I might have been able to dismiss that.


what the beep is on da go?
If a blockage is suspected, then a high power flush is in order while the thermostat is removed.

Posted: December 24th, 2005, 11:06 pm
by MOSES
ok, here is some more,

I Have NO AC.
both lines stay semi warm/hot when the car has been fully warmed up, both lines stay semi warm even with the fans on high.

"both lines as in send and return"

the thermo(thermostat) opens and works perfect keeping the cars temp stable.

i did the old card board in front of the rad trick to see if i could get the water warmer, the car got warmer very hot, close to the top of the gauge(within safty range). But the air stayed the same temp inside the car, just enough to freeze my nips off.

and Merry Christmas everyone.

Posted: December 25th, 2005, 2:25 am
by hgallegos915
maybe your vents are staying open, one thing i love about mx3s is the heater...woah its HOT... check the vents i have a feeling your hot air is going somewhere.

Posted: December 25th, 2005, 11:38 am
by MOSES
well, i check under the dash and the square hosing is in place, it pumps out lots of air, just not hot, so the heat is defintly escaping somewhere.
the mode switch works (face, feet, windshield selecter)

getting back to the heater core lines.
is it possible that there is only slight amount of flow and the water is warm, when i turn the fans on that bit of water cools off, but just the same, both lines stayed warm yesterday and never seemed to loose temperature.

Posted: December 25th, 2005, 12:14 pm
by jschrauwen
MOSES wrote:everything on the dash is in working order, all cables and buttens. it seems to me that there is sufficiant flow to the core, a-- soon as i turn the fan on i get warm air for 3 secs. then cold from there, where can there be any blockage?
what the beep is on da go?
Moses, this is really taking quite some time to diagnose. I was hoping that you would answer every question that I asked so I wouldn't have to repeat them. I asked if the you verified that you squeezed all of the coolant lines while it was running, not only to check for hose temp but also for pressure - Do any of them collapse easily? If there's a possible air lock, did you try starting a cold engine with the fill cap off so as to allow any air pockets to purge? I highlighted your quote just to verify that we are talking about a 92/93 since you made no mention about this at the onset and which I now kick myself for not asking ahead of time. You realize that this sort of information is helpfull since you're not a newbe. Getting back to the heater controls. Now it's time to knit-pick - since I'm guessing it's a 92/93 than your heating/cooling controls are cable actuated. (and I believe that the electric controls of the 94+ are servo actuated - someone verify this please). When sliding the heater contol lever is the cable actually rotating the mechanism on the heater core? Just because the switches slide and move, doesn't necessarily mean they are moving the actuators unless you visually inspect the process. This process should also be verified with the 94+ MX's. If there's equal pressure in all of the coolant lines in the engine bay (squeeze test) then it has to be the heater core - and either it is plugged or the servo/actuator is stuck or broken. Have you done a dash swap or something similar to this?

Posted: December 25th, 2005, 12:48 pm
by MOSES
"not only to check for hose temp but also for pressure - Do any of them collapse easily?"

Well, when the car is cold, the thermostat lines is collapsable and cold, but after warm it is hot and pressurized.

"did you try starting a cold engine with the fill cap off so as to allow any air pockets to purge?"

yes, no air is left in the engine.

" I'm guessing it's a 92/93 than your heating/cooling controls are cable actuated."

No, im sorry, its a 96, it has servo controls, and yes they all work.

"Just because the switches slide and move, doesn't necessarily mean they are moving the actuators unless you visually inspect the process. "

trust me, they all do there job perfectly.

"If there's equal pressure in all of the coolant lines in the engine bay (squeeze test) then it has to be the heater core - and either it is plugged or the servo/actuator is stuck or broken. Have you done a dash swap or something similar to this?"

sqeeze test has been done.

now, my last question, which "servo actuater" are you talking about?

Posted: December 25th, 2005, 1:27 pm
by jschrauwen
MOSES wrote:now, my last question, which "servo actuater" are you talking about?
The one for the temp. It should be attached right on the box that houses the heater core itself. In theory, it will close off the incoming coolant (hot or cold) and bypass it back out to the return line and back into the engine bay where you'll see it connect to the rear section of the thermostat housing (tripple connector). I'm thinking that it may be necessary to actually remove the heater core to verify that the actuator is serviceable or not. A pretty involved process by looking at the larger shop manual Supplement (Body Electrical - Section G). It calls for removing the dash but but I can't see that being necessary to get at the core itself. Don't know where to go from from here though. Hope this helps.

Posted: December 25th, 2005, 2:03 pm
by MOSES
well, the cold hot switch on my car is actually a slider, the rest are push buttens(electronic servos"

thats the slider that connects to the heate housing like you said, the one with the core inside.
It does pull the cable properly and makes a noise like a closing door inside the heater housing, im geussing its working.

but according to your relpy you said it actually redirects the coolent back to the engine.
is it the coolent or just the air that switch operates?

Posted: December 25th, 2005, 3:26 pm
by jschrauwen
MOSES wrote:well, the cold hot switch on my car is actually a slider, the rest are push buttens(electronic servos"
thats the slider that connects to the heate housing like you said, the one with the core inside.
It does pull the cable properly and makes a noise like a closing door inside the heater housing, im geussing its working.
but according to your relpy you said it actually redirects the coolent back to the engine.
is it the coolent or just the air that switch operates?
I was taking a stab at the heat, no heat cut-off based on other cars I've (owned) worked on. Could very well be that the core always gets a constant supply of coolant all of the time and it's simply a matter of a trap door that either allows or prevents air passing by it to give you hot or cold air. If you believe that that trap door is functioning properly, than you've narrowed it down to the core itself and that indeed appears to be plugged to a greater extent. That being the case, and before you may decide to tear the access panels off to remove the core, perhaps you may be able to clear the clog. I'm thinking that perhaps when you changed your water pump a piece of scale may have travelled through the coolant lines and jammed itself in the heater core. This could only happen it the cooling system wasn't properly maintained in the first place and either regular changes or flushes weren't done or the water used to mix with the coolant was hard water and not softened de-mineralized water. Too late for that now though.
I would probaly try and find some sort of flushing/cleaning agent that is able to breakdown or partially dissolve that probable clog. Unless you have the means to do that yourself, a good quality rad type shop may be able to assist in the complete flushing and purging of the cooling system in an effort to dislodge that probable plug.
If trying this at home first, tap into the heater return line in the engine bay and install a "T" connector (from any automotive supplier) inline. This "T" must have a garden hose threaded prtion and the 2 barbed endeds that go into the cut hose. Remove the thermostat and re-install the thermostat housing without the thermostat in it. Open the drain plug from the rad (passenger side of rad) and connect a garden hose to that threaded fitting in the "T". Provided that you've got at leats 60 to 65 psi water pressure to draw upon this may not be enough pressure. If more pressure is need (and I've never tried this part before), try connecting a home power washer hose to that "T" fitting. I'd recommend you had a second person around to assist with this. Hopefully this may dislodge the possible blockage. If so, I'm sure you can figure out the rest to put back the proper water/coolant mixture and allow the system to purge and pressurize itself - of course, that's after the screw cap is placed back on that new "T" fitting and the new thermostat is replaced (why not put a new one in while you're at it). Hope this helps a bit.

Posted: December 25th, 2005, 4:43 pm
by XxantwawnxX
Our cores get coolant constant.