I have a heater that only produces lukewarm air. I inherited this car from my father. He did a timing belt kit on it with the water pump at a mechanic shop so I'm assuming they at least replaced the coolant fairly recently. I've read how you can jack the front end up to bleed the air out of the system Is this all I need to do? I've tried reading through the forums, but don't know where to look or start.

 

Did you read post #7 instructions? Are they not clear enough?


http://forums.maxima.org/showthread.php?t=548975

 

start with the bleeding first...

 

check your heater valve ,its on the middle upper part of the firewall .it has a few small vacum hoses and a bigger 1 inch'ish heater hose
have the car running,stare at the valve arm(its stainless steel and few inchs long with a bend) and have someone move the temp selector on the climate control unit to full cold which closes the flow to the heater core(for colder air)
and when they slide it back towards warm the valve arm your looking at should move
ive seen the vacum hoses on these split at the connections or just disconnected or fallen off a few times if you replace them do them one at a time because they're mix up-able
i dont remember if a loss of vacum signal would leave the valve open(heat)
or closed(no heated water to the heatercore)?but its very easy to look and check since you just pop hood(car running) and look while the hot\cold lever slides ,and dont force the valve arm by hand because youll pop the diaphram

 

iirc, loss of heat for me.

 

i was looking at that on my own car today. strange thing is, my water valve solenoid DOES NOT actuate.... at all... yet the slider still affected air temperature.

not to mention my a/c compressor clutch just failed, the bearings in SOMETHING are shot and one of my belts (presumably all of these problems are on the a/c compressor) makes weird noises. and my ASCD set/coast button only works half the time. i blame the coldness.

 

So the heater valve caused you a complete loss of heat or only partially? My heater feels pretty good when it isn't extremely cold.

 

well, when i had the vac lines backwards i got no heat, valve didn't move. after i fixed it partial heat. re-burped my system, more heat. I think i still got some air, but im working it out....

 

[QUOTE=capedcadaver;6170471]i was looking at that on my own car today. strange thing is, my water valve solenoid DOES NOT actuate.... at all... yet the slider still affected air temperature. end qUOTE]

so if yours doesnt move and you still get heat then i guess if they stop working they stay in the open postion(water flows to the core)
so when your sliders on full cold it WONT close(stopping water to the core)
so you wont get maximum cooling with your a\c

check you vacum hoses and the one off the manifold and the middle connector on that hose they are probaly loose and splitting at the end
heater valves are pretty easy to change out and almost all junkyard cars still have em on

 

i think it affects cold air or a\c if the valves not worky

 

my plunger is OUT all the time. vacuum line has vacuum and is attached to the valve. well there's 2 at the valve. i'm going to go check out the lines real quick plus shoot a few little videos since i have a few things i wanted to have videos of anyways

 

I have my valve disconnected to get heat inside. Seems like my Auto system for heat has failed and if I increase the temp setting while in auto, all I get is AC air unmixed. So to get heated air in the winter I disconnected the vac hose to the valve. Cheap fix I know but it's a work car and I can live with it..however everything else is in top shape. A very good car with 135,000. I have another 2003.

 

the factory service manual(fsm)has lots of info on troubleshooting
you climate control
till then are you at least plugging that hose you disconnect?
and is your fresh vent lever open?because it will constantly let in outside fresh air when its open or if the (lever to slider cable)is busted or disconnected this is most noticable in def mode(warm air goes to windshield vent)and cold fresh outside air comes out the face vents i like this feature
after i tried it after years of not using it

 

This is a dummy question, but have you tried checking the thermostat? I had a 92 SE that hardly pumped out any heat, but the temperature gauge would never really go up. It would just stay barely above the "C" mark. One time it did go up while I was on the highway and then just started to "cool off." I thought that that was pretty interesting.

 

You are right on the fresh comming in when the unit is off and no I have not pluged the hose, but I will do so. Car runs fine. I have the 1994 manual but I have just not had the will yet to have a look at the possible causes. I was thinking the valve is kaput as was my experience with the water walves on GM cars in my younger days. My tinkering days are long gone

Thanks

 

be sure to loosen (do not take out) the nut at the upper right corner (standing in front of the car) of the intake manifold after letting the car idle for a few minutes, this is the highest point of your coolants path and will get rid of a lot of air pockets.

 

if you have your IM coolant channel bypassed (for the purposes of complimenting the function of NWP Intake Spacers, or just because) you can't use that bleeder bolt to bleed the system, because that whole IM coolant channel is bypassed. I haven't ever properly bled my coolant system, which is why my heat no worky, as i have no good hills in my yard to get the radiator to be way up in the air. but it's just as likely for me to have a crap heater core...