I've got another puzzle to solve: my heater doesn't heat as good as it is supposed to - it should be hard to hold your hand against the vents on highest temp setting and it is not at all in my case - the air is coming out just warm. I know the most likely cause - 'clogged core' which needs replacement. I also know what's involved. So, before going there I tried few simple tests - disconnected hoses going in/out of the core and tried to flush it using garden hose - the water came out freely. Another reason holding me from ripping it apart is that BOTH hoses are very hot to touch when the engine is at its working temperature - there must be a circulation there, otherwise I can't see how it is possible.

The question: what else can be wrong besides the heater core? Car has automatic climate control unit.

 

air pocket? esp on VG 3rd gens, they tend to trap air in the heater core. park it on the steepest uphill grade you can find and rebleed the coolant.

 

yeah when I got my Maxima the heater was luke warm unless i was hard on the gas. Bleed it real good and it blows nice and toasty now.

 

Mine is VE, I forgot to mention. I already bled it while being slightly up in the garage just because of the floor grade but it might be wasn't good enough. I thought that if lower hose is just as hot as the upper one then air misses the heater somehow and coolant returns back not 'cooled' at all. I'll give it another try at higher angle anyway since it's simple to do.

 

My heater core was working fine until a few days I noticed that it wasnt heating or rather getting as hot as it used to be. I thought nothing of it until one cold day I was driveing to Charlotte, and The heat was blowing out warm air only even at the highest setting! The windows started fogging up and there was an antifreeze smell in the car! Lo and behold I found out later that there was a puddle of coolant all over the passenger side floor! I have it bypassed for now!

 

be sure to bleed it with the engine running and at op temp. I bled my VE on flat ground in 0 weather in AZs parking lot took me about 30-45 minutes to do it, and the heat worked great.

 

I did mine by allowing the system to build pressure and then relieve it while giving it gas. Just constantly kept topping the radiator off and after 45 min or so the level quit dropping and heater and everything worked great.

 

I never have gotten any of my three to heat like they should. I've jacked up the front end, parked on a hill. What do I have to do?

Yes, my SE would get nice and toasty if I was running up over 3500 RPM, but that meant I was running hard or doing 85+

 

if you have tried to bled it and still no hot air then you could be having a clogged path somewhere. For me, it was the water coock that control hot water from getting in/out of the heater core on the firewall. I called courtesy and they wanted $125 for it ....I couldn't believe it. $125 for a water coock is ridiculous. Oh yeah, my water coock would not lock, it keeps letting hot water through so I ended up manually zip tie it during hot seasons and untie it during cold seasons.

 

easier way is to set it up like what my maxima has right now, due to the fact that my hot/cold slider jammed on the hot side. if i want to disable the heat, i just pop the short 4" line off the valve itself (the metal part) and hook the long line from the UIM up to it. if i want heat again, i set it back to stock.

 

yeah, I've tried switching vacuum lines but for some reasons the coock would not close all the way doing that so I have to zip tie it.

 

o ok. in that case the diaphragm is probably ripped or the hose has a small vac leak that's just enough to keep the valve from closing.

 

I've got two 93s and a 92... they're all exactly the same: adequate but takes a long time to need to turn it down in cold weather.