Sounds like a defective heater core
I would change the thermostat first. If that dont work change water pump
Purchase a Purolator Cabin filter. It comes with complete instructions on how to change it.
Air shocks on a Buick Park Ave are adjustable to give a smoother ride. If a shock or compressor fails, the rear of the car will sag an possibly drag on low road bumps.
You may have a loose vacuum hose either under your dash, or in the engine compartment.
The Buick Park Avenue line is known for its smooth ride. The suspension is an air ride, giving a soft floating feel.
Check in the air filter housing.
It means the rear air suspension is trying work,level the ride height.
The 1991 Buick IAT sensor can be found in the air intake hose. The IAT sensor will be between the air box and the top of the engine.
How to fix heater in Buick there is cool air ,fan is work .but no warm air
Check the following items............... 1. A/C heater controller. 2. A/C heater controller doors.
usually system is low of freon when this concern occurs. if 134 freon is ok then temp doors may be out of calibration. djones1
Its either a bad heater core or a clogged one. They are very expensive.