Hello Members....new guy here. Not new to cars but new to this Forum. We have an '09 Sonata with the 4 cyl engine...sunroof, leather, dual heat, auto, etc. I think it was close to a top of the model line. The car has appx 84,000 trouble free miles....until this past week.
A week or two ago I replaced the plugs using the NGK iridium brand that I purchased from NAPA. No problems, very straight forward and an easy change. Not something I can say for my '05 STI or my '06 Ford with the ground strap plugs that can break off deep in the head. BTW, the original plugs that I removed looked excellent. Very clean, the gap was still correct and the Denso plugs actually looked like they are better made than the NGK plugs. I took some very clear close up pictures of the plugs if anyone wants to see what these plugs look like at this mileage.
I also replaced the air filter, the cabin filter and unscrewed the radiator cap to have a look at the coolant. It was clean, green and at the proper leve. Then beginning during a 300 mile drive the right side of the heater quit working. Cold air only will blow out. This is regardless of any heat setting or combination of heat modes, dual on or off. The drivers side will only blow lukewarm heat even with the setting all the way to HI.
So I was wondering if the thermostat might be bad or if this is an electrical part problem in the heat selector. I don't remember the normal position of the temperature needle but it is now just below the middle position by appx 1/8". Also, after several fill ups the car is now delivering appx 3 to 4 fewer miles per gallon. A recent trip, one week earlier, yielded 33 and 34 mpg at a constant 80 mph interstate trave. That had now dropped to 28-29 mpg although the engine runs smooth and accellerates as it did before. There are no check engine lights. I couldn't find anything on this will a search. Any ideas on what the issue might be. If the engine is running cool does the computer shift the heat to the drivers side? Note that the drivers side will not get really hot air. Thanks in advance. Hwy61
A week or two ago I replaced the plugs using the NGK iridium brand that I purchased from NAPA. No problems, very straight forward and an easy change. Not something I can say for my '05 STI or my '06 Ford with the ground strap plugs that can break off deep in the head. BTW, the original plugs that I removed looked excellent. Very clean, the gap was still correct and the Denso plugs actually looked like they are better made than the NGK plugs. I took some very clear close up pictures of the plugs if anyone wants to see what these plugs look like at this mileage.
I also replaced the air filter, the cabin filter and unscrewed the radiator cap to have a look at the coolant. It was clean, green and at the proper leve. Then beginning during a 300 mile drive the right side of the heater quit working. Cold air only will blow out. This is regardless of any heat setting or combination of heat modes, dual on or off. The drivers side will only blow lukewarm heat even with the setting all the way to HI.
So I was wondering if the thermostat might be bad or if this is an electrical part problem in the heat selector. I don't remember the normal position of the temperature needle but it is now just below the middle position by appx 1/8". Also, after several fill ups the car is now delivering appx 3 to 4 fewer miles per gallon. A recent trip, one week earlier, yielded 33 and 34 mpg at a constant 80 mph interstate trave. That had now dropped to 28-29 mpg although the engine runs smooth and accellerates as it did before. There are no check engine lights. I couldn't find anything on this will a search. Any ideas on what the issue might be. If the engine is running cool does the computer shift the heat to the drivers side? Note that the drivers side will not get really hot air. Thanks in advance. Hwy61