I have been suffering little heat in the winter. After the car warms up, I get some heat, blower on 2nd speed. But not the volumes I used to get before the dealer did my timing belt job a few years ago. I think I may have an air lock. I have checked the heater core..it flows easily. The heater valve also moves when the heat selector is moved..the inlet hose to the valve is hot..the outlet hose is not. Can't figure this out?? What am I missing? What could they have done when the timing belt was changed?? I received the car back that day with the air relief screw open! I had to tighten it myself..Looking for heat! Thanks for the advice.

 

It might be your thermostat. Does your temp gauge still go up to about midpoint, but take much longer? That's what my problem was. I replaced the thermostat and everything was back to normal.

 

Tom..the needle has not changed..still goes up quickly enough..I think I will check the heater valve once again..maybe even connect the system bypassing the valve..the heater hose inlet gets really hot and the output hose is not...I wonder if the valve can move, but still not really open??

 

hopefully this is your 10 second fix...

walk out to your car...look at the temp controls for the heat. on the left side there's a lever that goes up and down. make sure it's in the DOWN position. hope that's it.

 

Dan..good tip, but I have never moved the fresh air/recirc lever..evidence also is the fact that I do get heat..just not strong enough..more like a trickle..however, it is probably a good idea to exercise it just be sure the damper seal hasn't moved..but I don't think so..

 

well when that lever is up you get very little heat..but it's there. when you move it down the heat comes blasting in.

 

I have almost the exact same problem. I changed my Timing belt in august, along with my thermostat. And now it takes soooo long to get any heat. And then it only wants to work when I am WOT. I just don't understand it. Last winter the heat was great, but now its pretty much not even there.

 

Nice to know when I am cold in the Northeast that I have company! My only other idea was something about being air-bound. There are hints in some other postings about cooling systems having air pockets..There must be a method (undescribed anywhere in the shop manual that I could find..)for purging the air. If someone knows, please tell us. I hesitate to bring it to a dealer..I'll end up with a new heater, in a flash..Thanks, FFxMax.

 

What EXACTLY is that lever for anyway? I looked in the owner's manual and it wasn't very clear either. Why does it exist, and what is it's "official" name?

Thanks,

 

Not sure of the name..but it is a fresh.outside air swaitch..if it is up, you get fresh air through the vents..and the air bypasses the heater/AC unit. If it is down, the air goes through the unit and is heated or cooled..

Still looking for tips on air pockets and air purging in the cooling system!!

 

Hmm... well.... you can try the method that works in the RX-7's. (They are a PITA to get blead totally) I kinda doubt it applies to Maxima's but it will ensure that you have a properly filled system. I'm going to try to adapt it to Maximas here :-)

1) Remove radiator cap / air bleeder and turn heater on full heat

2) Fill the radiator slowly with coolant

3) If coolant is coming out of the bleeder while you pouring it in, then put the bleeder and continue filling the rad with coolant

4. When you THINK you have it full of coolant start the engine

5. Allow the engine to warm up with the radiator cap removed, while it is warming up occasionally loosen the bleeder screw to release any air that may remain in the system. While it is warming up you will see coolant spilling out of the radiator.

6. You will know it is at operating temp when coolant starts flowing though the upper radiator hose (will get hot). Also you will probably notice a slight level drop when the thermostat opens. Make sure that the level never drops below an acceptable level. (Car could overheat)

7. Now place a funnel (funnel should minimize the amount of coolant that is shot out of the radiator) on top of the radiator and slightly rev the motor. You also may want to carefully squeeze the radiator hoses to try and force air pockets out. Still, keep an eye on the fluid level in the radiator. Loosen the bleeder screw AGAIN to vent any potential air. If you just get fluid coming out of the bleeder close it back immediatly. At this point make sure that your coolant overflow bottle is overfilled (slightly).

8) Put the radiator cap on, and you should be able to drive the car normally. (After you clean up the TONS of coolant that you have spilled) Take it for a test drive and keep a careful eye on the temp gauge. If it goes up TOO high (it really shouldn't), stop the car immediatly and allow it to cool off and then top off the coolant.

9) Allow the car to cool off, while it is cooling off, check the overflow bottle everyonce in a while to ensure that it is not going to be depleted. Once the car is totally cool, top off the overflow tank to the "Max" mark.

10) For the next few days keep a careful eye on the coolant level in the radiator (only check when cold) and the overflow bottle. (Keep it at "Max")

On a 2nd gen RX-7 it typically takes ~45 minutes to fill it properly when following these steps, so don't be discouraged if it seems like it is taking a long time.

Also, there is another POSSIBLITY as to why your heat doesn't work better... Have you (or the previous owner) EVER used the radiator "Stop leak" products which are typically sold in Pep Boyz, Autozone, etc? These products have caused some issues in RX-7's because they are designed to "clot" or become solid when they come in contact with the air. If you had a "stop leak" type product in your car when you took it to the dealer, then it is possible that some residual could "clot" in your heater core. The COULD cause your heater core to become stopped up from the "Stop Leak" type stuff. This problem HAS happened on RX-7s...

Sorry for the length, and sorry if all of my knowledge comes from RX-7s... but basically it is the ONLY car that I have known for the past 6 years. And please forgive me for any typos... I'm too tired to proof read :-)

Take care,

 

try filling the radiator to get the air out while the car is on an incline, or with the front end jacked up

 

After 3 months of little to no heat I fixed mine. It turns out that when I ordered my thermostat it was the wrong one. There are different thermostats, and when I replaced mine with one I bought from a local Nissan dealership, instead of the one in Chicago, I now have lots of heat. So you might want to try replacing your thermostat, which is what fixed my problem.

 

I had the same problem. I called the dealer and they said you have to elevate the front of the car at a 45 degree angle to bleed the air out properly. Sure as **** it fixed my right up and i`ve been warm ever since. Good Luck

 

hmm... damn im having the exact same problems too... im not sure if its the thermostat becaue my temp needle functions fine, yet there is limited heat, when i used to have HOT heat comoin out within a mile of my house...

for someone with limited knowledge and tools, how can i check and bleed the coolent system or check for pockets? damn this is annoying.. thanks!