I have a 1995 LS 147k miles with climate control problems. At first, anything below than 900rpm brought me lukewarm air through the vents. At speed the air coming out was hot. At idle and on deceleration, the air temp plummeted. Checked quality/color of coolant, heater control valve, and tstat. All tested ok. Dealer verified what I found and diagnosed the problem as a failed heater core. $2500. There are no coolant leaks or wet carpeting to back this claim up.
Before deciding on the car's fate, I replaced the expansion tank cap last night. Suddenly, the air blows nice and hot...
...From the driver's side vents only. Even with the dual temp feature shut off, the pass side vents blow lukewarm air even on max hot setting. To sum up, current problem is hot air from driver's vents, lukewarm from pass vents - front and rear. Could this be a servo/door/relay? I am still learning the ins and outs of owning this beauty even after 2 years.
Anyone have a thought on what to try out next?
Thanks,
