1998 Mazda MPV heater problem

BMARRERO08

MEMBER
1998 MAZDA MPV
96,000 MILES

The heater worked fine about 3 months ago, then all of a sudden it doesnt heat at all. Its not blowing out icr cold are but rather a room temperature. What is the cause & how do I go about getting it fixed? Also 2 more things that are wrong that need a fix.I fill up my gas tank but since yesterday it is only showing thst theres half a tank. As well as when my car is stopped at a red light or stop sign it makes a kind of humming noise. What would be the cause of that?

Tuesday, November 19th, 2013 AT 8:06 AM

2 Replies

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

With the engine at normal operating temp and the heater on high, check to see if both heater core hoses are hot.

Let me know what you find,

As far as the fuel gauge, chances are the rheostat is bad or going bad. The bad part is it is part of the fuel pump.

The humming is hard to diagnose not being there to hear it. Are there any specifics you can tell me?

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Tuesday, November 19th, 2013 AT 8:16 AM

WRENCHTECH

MECHANIC
20,761 POSTS

With the engine at full operating temp, locate the 2 heater hoses where they go into the firewall and feel them to see if they are both hot to the touch. If they are both hot, the heat in that vehicle is controlled by a blend door that regulates heated air flow. It is operated by an electric motor/actuator. The problem can be that the actuator is stripped or inoperative or the door itself could be damaged. This is what needs to be determined by examining the actuator and see if it is responding to heat change commands or not.

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Tuesday, November 19th, 2013 AT 9:40 AM