i have a 1990 maxima and the heater is not working correctly..

i let me car warm up until the engine temp. is normal.
but when i turn on the heat, i either get cool air or luke warm air.
no matter how long i let it idle, there's no HOT AIR !!

sometimes while driving, the air will kick in REALLY HOT (FINALLY) but then minutes later, it's back to cool or luke warm.

i've changed the thermostat and i had my system bleed just in case their was some trapped air in the system BUT the problem persist..

I would appreciate any help than anybody can give me, thanx..

 

Sounds like a bad heater core to me.

 

are these 3rd gen max's known for bad heater cores?

 

I am not sure. Anyone?

 

Mine died because a penny fell down my vent and wedged itself next to the core...
I've seen a couple people with this problem, but not many, only like 3 or 4 in the last year (That I saw)
Take my advice, find a couple friends that are mechanically inclined and do it on a weekend... It's in the books as a 12 hour job, and it WILL take that long.
It took my brother and I 13 hours to do it, and we did it over the course of a month.

 

Dude that sucks. I would almost feel like its a waist spending that much time on a non-performance related problem. Of course, I live in Phoenix which pretty much rules out the regular use of a heater.

 

My heater does this also but it never gets hots only two vents blow warm air the other two blow cold i havent replaced my thermostat yet nut i will soon do that and fix my heating core my cousin has a 92 max and here heating core went bad