# AC/Heater problem MAXiMa 87. Help please



## JamesNguyen (May 5, 2005)

Hi everyone !

This is my first time here. I am glad to see all of you who actually give me an advice or a help for my nissan's problem. 

I bought my Nissan Max 87 in 1995 from the first owner who took care this car very well in the past. I have been driving this car for many years with pride and happiness. My car sometime got minor problems that I can fix my self or go to local shop to fix it. The most things are replacing the old part that was old enought to be replaced. Recently, I got a problem that I could not figure it out. That is my car keep flowing out the hot air from the vent holes. No matter what I adjust the bar on the temperature control and how cold the temperature out side the car was.

I dont know where the hot air comes from. At first, I thought my AC is not working, but it does. In fact, the hot air is too hot. that make the AC could not be cold anymore after awhile. 

I dont know if the temperature sensor control is not working properly or there is a door which close/open the hot air had been broken. By the way, my car is reaching over 235,000 miles now. The thing is I dont want let the shop fix my car since may cost the money that over my car's value now. I like to do it myself or at least knowing how serious this problem is and how much it may cost.

Please help. Thank you for any advice or suggestion.


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## Matt93SE (Sep 17, 2003)

does the thermostat control lever on the dash still have tension on it, or does it slide freely now?

it's possible the cable has come undone from your air mix door (the one that directs air over the heater core and AC evaporator).. if that's the case, then you should feel little resistance when changing from hot to cold air.

Also check your heater core flow valve. it's a strange looking contraption on the heater core hoses on the engine bay side of the firewall (at least it is on 3rd gens).. it's supposed to shut off the flow of coolant to the heater core when you have the temp control set to full cold. sometimes that guy can fail and will still allow hot coolant to run through the core and heat up the air stream.

other than that, you're just going to have to crawl under the dash and start looking. those are the first two obvious things other than your A/C compressor not running.

good luck.


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## JamesNguyen (May 5, 2005)

Thank you Matt for you suggestion. I think your opinion is right. 
Recently, I went to the junk yard and check out some max 87 and try to pull everything from the dashboard out to see what the heck after the dash board are removed but I did not have enough time at the junk yard. with 2 hours I havent completed open the dashboard out. the reason I went to the junk yard is to practice on the junk car first before I work on mine. It is a good place to practice something you dont know. you may brake some part on the junk part rather than your car's parts. I experienced that on the max 87, there are many crews that I needed to uncrew. wow I got tired at the junk yard with the dust on the floor (not the floor of the car) and the heat over 110 degree F. I think the heater core valve is the problem that my car got. 

Well, I asked somebody on the junk yard about this problem. Some suggest that I swap the cooling tubes running in the heater core may solve the problem. I asked if i put a valve on the tube and they said it will be solve the problem too. I guess I have to put a lot of time on this problem. the major investment time will be put on openning the dash board out completely. how about your suggestion ?


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Matt93SE said:


> does the thermostat control lever on the dash still have tension on it, or does it slide freely now?
> 
> it's possible the cable has come undone from your air mix door (the one that directs air over the heater core and AC evaporator).. if that's the case, then you should feel little resistance when changing from hot to cold air.
> 
> ...


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