RelentlessEVO

iTrader: (4)

Alright,

I recently purchased my third Evo; it's a 2003 with some minor bolt-ons. To make a long story short, when I purchased it I was told the knobs for both mode and temp were not working and the owner wasn't sure why. I wasn't too worried about it and after purchasing it I replaced both cables for the temp and mode along with the gears (new revised ones) for the temp.

Two issues remain:

1. The mode knob still doesn't turn all the way to the right (full front defrost mode). Every other mode does work, I can change it from feet only, feet and head, head only and finally feet and defrost and they all work.

2. The temp knob moves freely, however, the temperature never goes full hot or full cold, even on "max a/c". I can assure you that driving in the freezing cold this morning with no real heat did not make me a happy camper.

I'm REALLY hoping it's something other than the main HVAC box behind the dash. I know my way around an Evo pretty well, I've replaced turbos, clutches, pulled motors, done timing belts, etc. But honestly, I don't know how the HVAC system (in any car) really works. I have a basic understanding, but that's it. My basic understanding is not helping me understand why even though I can move the heating knob full spectrum, it still doesn't really change the temperature the way it should. I would like to note that it DOES change the temperature, just only a little bit. It doesn't get very cold or very hot.

Any help here boys and girls?

Thanks for reading,

Bill

DontStopMe

iTrader: (19)

Probably not the problem, but just to make sure, did you align the new gears properly when you installed them? That could be the cause for the hot/cold temp switch not working properly.

I've haven't touch my cable for the "mode knob" but I'm wondering that could be a similar issue.

this video may not address your specific problems, but it can at least give you a look at a system that works properly.

http://www.youtube.com/watch?v=vcG20LmRZFU

I would also make sure your thermostat is not stuck open.

DSMdynamic

iTrader: (38)

https://www.evolutionm.net/forums/ev...ega-guide.html

RelentlessEVO

iTrader: (4)

Hey guys,

I appreciate both of your responses. DSMDynamic, I've reviewed the HVAC Repair - MEGA Guide before I replaced the gears and the cables. It does not address my specific problems that remain.

I will triple-check the alignment of the gears, but I literally had the video playing while I was installing the revised gears and made sure the pin was aligned properly with the new gears.

Assuming that the pin isn't somehow misaligned after installing the gears (in other words, it is still aligned and good to go), any other suggestions as to why I can't get heat from the heater?

-Bill

stroked4g63

iTrader: (2)

im pretty sure mitsubishi has a recall or updated parts on this problem. call ur local dealer to confirm..

RelentlessEVO

iTrader: (4)

stroked4g63,

Thanks for the response, however, I specifically stated I've already replaced the gears with the revised gears. That is the recall that you are talking about, yes?

Unfortunately, that doesn't help me now. I've replaced both cables and the gears and I still don't have heat. Driving to work in 18 degree weather without heat this morning was not fun.

DSMdynamic

iTrader: (38)

Did you check the coolant level? Could also be the thermostat or heater core.

RelentlessEVO

iTrader: (4)

DSMDynamic,

I checked the coolant level, it's good. I have not checked the thermostat, I'll be checking that in the next few days. I really hope it's something as simple as that.

As far as my A/C goes, I don't think my compressor kicks on when I turn on the A/C. Now, the only reason I think this is because typically when you turn it on, your RPM's drop momentarily and you can hear it as well. Inside the car, I can neither hear the compressor kick on nor do the RPM's drop.

I'll have to actually have my brother turn it on while I look at the compressor in the engine bay with the motor running to verify though.

Thanks for the ideas everyone!

DSMolition

iTrader: (17)

I had almost the same problem. The knobs would not fully move the gears. I ended up taking out the white box that the dials are on and it was that the cable was bending and not pushing into its sleeve. There was some play in the "eye" part of the cable that would move up and down when i would turn the knob. I ended up putting screws down through the "eye" of the cable and it fixed it.

Maybe remove all the dash peaces then move everything around and get a good look at what is going on.

RelentlessEVO

iTrader: (4)

Okay, just to give everyone an update (for anyone who actually cares haha), I replaced my beat-up and poorly patched OEM radiator with a new Mishimoto radiator, I once again replaced all my coolant and made sure there were no air bubbles in the system.

After doing all that, I STILL do not have much heat through the vents. I checked and it felt like only one line going into the heatercore was hot, the other seemed only luke-warm. I am now guessing that the heatercore is blocked (remember, the coolant that was originally taken out of the car was extremely muddy and dirty).

Also, my A/C compressor does not kick on when I turn the A/C on in the car. It doesn't look like there is any refrigerant in the line. I'm not too surprised as at one point the motor was removed when the car was entirely re-painted (bay, jams, everything).

Frustrating to say the least.

RelentlessEVO

iTrader: (4)

Update: I flushed my heater core last night and I managed to get some "crap" out of it. Looks like chunks of debris and just plain dirty/muddy liquid came out. I'm pretty positive the heater core is blocked and that is why I'm only getting a little bit of heat out of the vents. I'm going to button the car back up tomorrow night and check, but my assumption is that the little I got out will not be enough to unblock the core. I'll more than likely have to tear apart the dash and remove the heater core...yay.

Sucks to be me.

DSMolition

iTrader: (17)

AS for you ac problem, there should be a high side pressure switch with a 2 pin connector. Key forward and on the harness side. Take a paperclip or small wire and touch both pins together. This should jump-start the compressor. ( don’t leave connected if there is no refrigerant/oil in the system it will burn it up.) If it kicks on it is back in your ac switch/relay if nothing happens then it could be a fuse and I would start checking voltages. Just some simple things to look at.

RelentlessEVO

iTrader: (4)

I appreciate the idea there DSMolition. Lucky for me, my brother and my good friend both do HVAC work as their profession. So my buddy just picked me up the fittings so that I can actually read the pressure on both the high side and low side. I'll be doing that tomorrow as well. If there's no pressure (which I'm guessing there isn't) then I'll fill it full of nitrogen and locate any and all leaks. Once that's been done, I'll evacuate/vacuum the system and have my buddy fill it full of refrigerant.

This will be done after I've fixed my heating issue. Because if I have to pull that damn dash, I'll have to evacuate the system to pull the blend box / heater core. I'm hoping and praying that my heater core flush was enough to get the blockage out and I can finally get heat out this thing.

dastallion951

well if your thinking your heater cores blocked, what you can do is remove the hoses, and shove a water hose into the fitting put a rag on the other end to keep it from hosing your engine bay, and spray some water in through it, then after a few mins, switch and put the hose on the other side, cover other fitting, that should remove a lot more debris, ive seen really clogged up heater cores keep it from heating up to normal.

RelentlessEVO

iTrader: (4)

Dastallion951,

I appreciate the response. That's what I did, verbatim, last night. I'm hoping it cleared enough of the blockage that I can get heat, but I won't know until I put coolant in it and get it up to operating temperature. That won't happen until tomorrow night. But, wish me luck!