I've got a 90 maxima and its now cold in the land of the coldair, aka MN. Anyways, I am begining to relize that the heater in my maxima cant keep up with the cold. It blows luke warm air and cant seem to get hotter. So, yah basically what I am trying to say is the radiator in this car is way to good for minnesota weather. Anyone know how to cure this little problem I am having?

 

Does the temp guage stay in the middle or does it move down when you put the heator on? You might have a faulty thermostat that opens too fast. If you temp guage stays ok but you still don't get heat, you might have a clogged heator core or some of the valves aren't working right.

 

The temp gauge stays right about in the middle. I will look into that valve thing. I dont think its the heater core but I suppose I could throw a new one in just in case.

 

Okay, sounds like the radiator and thermostat is okay. DEFINATELY check the valves controling the water flow into the heator core and your control wires that are attached to your cold-hot climate controls.

Why? Because doing a heator core replacement in a maxima is one of the most irritating experiences known to modern man. I'd rather to an engine swap.

 

http://www.cybrrpartspro.com/Chilton...H06_3_IDX.HTML

 

No offense, but is your fresh air vent closed?

Someone had this problem last winter and we couldn't figure it out for like a month straight... Finally he posts "oh, yeah, turns out the fresh air vent was open the whole time"... lol

 

Heh.. that's the first questions I always ask, after doing the same thing in my car.


Otherwise, I'd point to a low coolant situation or air in the cooling system. the heater control valve is also a common problem. have the old one out of my GXE if anyone needs it.. someone else asked for it the other day and after I pulled it and sent pics, they never replied back.

 

Amen to that! This is exactly why I just bypassed mine and said F*#% it, I live in FLA anyways!

 

note to self: fix heater thing before it gets cold out again...

 

haha yeah with the fresh air vent open it gets really cold. Then I cant even getit to blow luke warm air. I was playing with the heater control valve and it doesnt seem to move whether the heat is on high or cold so I am thinking that may be a problem. That little vaccum powered cylinoid is supposed to move when you turn the heat on right?

 

oh I checked all the fluids and made sure that wasnt the problem.

 

i notice NO difference with that little lever... it makes a sound but there is no change in the power of the blowing nor the smell of it. i notice nothing... everything is cold on either setting and it's hot on either setting despite the temp outside... it's very odd...

 

yeah, the vacuum solenoid should move when someone plays with the heater thermostat controls inside the car.

Might be as simple as a cracked vacuum hose too.. those guys are small and get very brittle. mine didn't seal well for a while and I lost heat.. replaced the vacuum hose on it and it fixed it.
If not, as I said above, I've got the control valve off my parts car.

you might want to have a helper play with the temp control slider inside the car and you see what happens under the hood..

 

sounds like your fresh air intake vents are clogged..

when you open that, it's supposed to blow colder air out the dash vents to help keep the driver alert.. (supposedly nissan's theory)

 

alright I will try replacing all the lines. If that doesnt work then I am gonna send you some money for that new heater control valve.

 

I take it thats from the FSM?
Almost as funny as the little drawings they have in the beginning of it, you know, the ones for the air bag, anti-theft, seatbelts, etc (IIRC)

 

how might one clear these things out?

 

Power Flush!
Garden hose or better yet Self car wash hose!

 

arent they just the vents infront of/under the hood, where all the pine needles/leaves accumulate and then sometimes over time that promotes rust?

 

???????????????????????????????????????????

 

I'll swap you a Heater core job on a Maxima for a heater core job on a Fox chassis Mustang any day!

 

Mustang heater core is easy!
Just junk the car!

 

hell yeah. junk the car

 

I concur... I'm dreading the day I have to do mine...

 

yeah, i heard the fox's are pure hell, along with t-birds... like sell the car hell

 

where can i buy this heater control valve? i think i have this same problem. kragen and autozone dont carry the part for an 89'. any ideas where else might carry it?

 

You sure? In a maxima, you have to take out the ENTIRE dash area. ALL of it. Even the big brace that spans the whole width of the dash area.

 

yeah, but a Fox you have to do that, and mess with a stupid plastic box that is supposed to be hell, among other things. I dunno


Hey Jeff, want to replace my heater core? It works perfectly, but I want to do some preventative maintence heehe

 

I had the same problem about 3 years back. My temp gauge did go to the middle, but it started going to the middle much SLOWER than it did before. Usually it takes about a mile or 2 from my house, but it got to be like 5 or 8 miles.


I changed the thermostat (Nissan genuine part) and everything was fine again (back to a mile or 2 to warm up).

 

mine heats up very, very fast. makes me wonder if its reading correctly. although i have no heat so i need to do a flush tomorrow.

how exactly do you guys go about flushing the coolant system?

 

This doesnt sound like your problem, but just to FYI others who might read this. My Maxima slowly started to have less heat out of the passenger side vents. Driver vents were warm. But still the car's heater wasn't doing a very good job. One day the car started to run hot, for the first time. Turns out it was low on coolant. After cooling off, and topping of the radiator, and the overflow bottle, perfect heat!! Just something to think about if your pass. side vents start giving less heat-I was afraid a vent or vent motor was malfunctioning.

 

garden hose into heater core.

 

Took me 6 hours to do my heater core and still really didnt fix the problem. What I did see is that the design of the heater core sucks big time on our cars. And with the design I dont think it can keep up with really cold conditions.

 

my heat works great ever since i changed the radiator ................

 

I got a great solution on my car:
remote start
group deal here

ok self plug over.
But I do love the remote start

 

Hey Matt,
Is this the 'slide' switch that controls heat/cold? If so, and ya think it'd fit in my 93 SE Auto - I'll take it. Can you point me to the pics?

Thanks

Ken

 

Go check out the online chiltons for 3rd gen maxima's.

http://www.cybrrpartspro.com/Chilton...961m/8961.HTML

 

Thanks Guys, I never had hot air coming from the vents just cold, and cold mix with a little warm, until someone said that the master vent switch is actually a cool air vent and now hot air glory.

rymo.rymo

 

wish i had the same problem (switch being in wrong position)... i think my heater core is clogged again due to the crap that was in my engine.

 

i finally have heat now. i flushed my heater core really good. reverse flush, forward, reverse, hook the lower hose up, filled it up so there weren't any air bubbles, then finally hooked it all back up. the only problem i'm having is low to no heat when slowing down after cruising. anyone have this problem?