domlcardio

hey guys. whats goin on. i have an 89 maxima that i bought a few months back. its in pretty good shape. right now with 137,000+ miles. it seems that the previous owner really didnt take good care of her, but im trying my best. its getting me to my job, hehe. anyways, i have no heat which i know may be due to bad heater core or thermostat or something of the like. but also i have no rear defrost. does anybody know what may be wrong with it. thanks in advance guys.

mtcookson

iTrader: (2)

there is a lever on the left side of the air controls that must be pointing down to get heat. most likely that lever is in the upward position right now. if it is pointing down the heater core might just need flushed. if it needs replaced that'll cost quite a bit or take up a lot of your time to do. hopefully you just need to flip that lever down though.

choisky

mtcookson, thanks for your post. I had a similar problem as described in the original post. Kinda similar because mine blows only lukewarm air. Yes, the lever you mentioned is pointing down. So, I was wondering my problem may be due to "weak" heater core. I didn't know that it can be flushed, though. Could you tell us more about the procedure of heatercore flush? Million thanks in advance.

MrGone

iTrader: (30)

I have to swap out heater controls, mine doesn't go all the way over (only goes about 2/3, or about where the 'blue' part ends). Ofcourse I didn't think about it during the summer, but winter time is just around the corner and I better get that done. (really want auto climate control but I think I'm going to have to hold off ).

Heater core flush: you have 2 options, you can do it like an engine flush and just run the heater (engine has to be on) and just flush it a few times to be thorough. The other option is to just disconnect the heatercore hoses and just hook up a hose to one, then let the other one drain into a bucket and just keep flushing.

ForceFed

more than likely if your not getting sufficiant heat its because your thermostat is bad. If your tempature guage goes down when driving on the highway then your t-stat is sticking open. Plus its much easier and cheaper to change a thermostat than heatercore. A new one is only like 15-20 bucks.

alpicone

I read somewhere that you can just grease it a little where the lever slides and that will fix it. Just use a Q-tip to get in there. It happened in my car also and I tried forcing it and the lever cracked off if the hot position. But this was in the summer so I had to fix it right away.

mtcookson

iTrader: (2)

what i do is unhook both of the coolant lines going to the heater core. from there i'll hook up a garden hose and run water through the inlet of the heater core. once clean water comes out i'll then hook up the hose to the outlet of the heater core (the lower coolant port thingy on the fire wall) and i'll run water through backwards. so far everytime i've done all the crap got out of there and the heat worked perfectly afterwards.

maximaboi

iTrader: (1)

Im sure that my heater core is going out/gone. does anyone have pics of where the coolant lines are located? I want to try and flush it out before I have to take out my whole dash.

how much is a heater core going to cost me new from autozone or some place like that? I could go to a junk yard and get one but is there any way that I could tell if the one I was getting is good or bad?

thanks for your help! Nathan

mtcookson

iTrader: (2)

this is a picture of the top hose (inlet) for the heater core.

http://www.mtcmotorsports.com/coolan...%20tee%201.jpg

internetautomar

iTrader: (30)

Autozone and the like don't have a heater core listed for our cars.
the dealer is the only option right now.

MyMaxima29624

I actually got the same problem, but I just got my car in July (summer) so i wasn't thinking about heat.How hard is it to replace the heater controls? And thanks I actually didnt know that little lever had to be down (i wondered what it was far, but didn't wanna sound stupid askin)

avmaldo

take apart almost the whole dash. reconnect some wires and swap out a plastic swivel thing. not that hard just takes time.

NYmax91

all good segestions for the heat but what about the rear defrost? well i may have the answer. Check to see if the rear defrost lines (wich are brown lines on the rear window) are in tact, if not theres your problem if yes then also check that the rear defrost links are also intact, there located inside the car on the window by the C pillars. If there also in tact then its a fuse or the button or wires and the list goes on. good luck buddy! http://members.cardomain.com/nymax91

domlcardio

thanks everybody.

NYmax91

np killa....

ghostmax

iTrader: (4)

if you have enough coolant and you're not overheating, then the heater valve maybe stuck. it's located on the firewall right in the middle at the top. it has some vacuum hoses going to it and a harness or two. i was having the same problem, and i would disconnect the vacuum hose(s) with the air blowing, and the heat would magically come on. but for some reason, i stop getting heat and have to unhook/hook the hose back up before it works again.

xpl0sive22

where is the heater core located and how do i flush it... i have the heating problem too, and it also mite be the thermostat... so where is it located also... thanks... and how do i flush the heater core... as in where are the hoses that connect to it

mtcookson

iTrader: (2)

the hoses are on the firewall. there are two of them, one on top of the other, coming from the engine. the top one is the heater core inlet and the bottom is the outlet.

the heater core itself is behind the center console, right above the ecu.

maximaboi

iTrader: (1)

I would also like for someone to tell me exactly how I can flush my heater core. its getting cold here and I need heat

mtcookson

iTrader: (2)

pull the hoses off of the heater core inlet and outlet. grab a garden hose and hook it up to the lower one. turn on the hose and let it run till you see clear water. you may want to put a 90 degree hose on the inlet so that water doesn't go all over your engine. the inlet has a 90 on it already, just disconnect it from that valve, loosen it, and point it down.

once you're done with the bottom one put the 90 degree hose on the bottom/outlet and put the garden hose on the top/inlet and repeat the procedure. once you're done with that hook the hoses back up and top off your coolant per the recommended procedure of lifting the front end up.

aziphrale

when you say coolant you mean radiator coolant? What do you mean lift front end up?

Mattster

i think that will solve my rear defrost problem also.

Yeah MrGone you should get your heater working since its been in the 30s all week.

mtcookson

iTrader: (2)

yup, or also called antifreeze.

on i believe pre-90 max's (that's including 1990) the heater core was placed in a bad position to where sometimes it would get air pockets making the car not have any heat. to fix this you have to lift the front end of the car up something like 30 inches so that it gets filled up properly and doesn't have any air pockets.

internetautomar

iTrader: (30)

I thought it went up to 91 and it's like 39 inches.

mtcookson

iTrader: (2)

i'm pretty sure our 91 has never had that trouble. i know for sure my 90 has the trouble. i never lift mine though so i wasn't sure on the exact height.

aziphrale

Well i guess that i will flush the sytem this weekend and see if thats it. But i now have another problem. I would like to know if a kind soul whould know how to check to see if the rear vents for defrost is working. i noticed yesterday that the back window never defrost i dont have a problem with the front but the back is getting no air coming out whatsoever. is there something that i have to connect or something? By the time i get out of work all the shops are closed. Please help me obi wan. . Also i guess that the reason why is cause the car really has to warm for like a half hour to an hour because the heat will definetly be on after a while. How long does it take for other maxes to start getting heat? Do you guys wait this long as well? Also if i put the fan to 4 and heat all the way the heat air is warm not as hot as if its on 2 or 1. i think that its not getting as hot as it is supposed to. im sorry if this is getting tiresome. But i really would like to fix this or atleast know whats wrong with it. help?

internetautomar

iTrader: (30)

the rear defrost if the car is so equipped is a grid on the rear window. those "vents" on the rear deck only lead to the trunk no air is blown out of them

dewmax007

ya, so those vents at the base of the rear window are to allow air to escape from the car when you shut one or any of your doors. equalizes the pressure between inside and outside.... however truely sucks not having rear defrost that works. i have three bars, the bottom ones.