Q: I have a 2000 Olds Intrigue which had started to bang or thump every time I drove over cracks or expansion joints in the road. I took it to a repair shop and they replaced the struts and springs, both front and rear with factory replacements and now the car rides hard and the thump or bang is still there. It seems as if the tires are just bouncing around under the car and it’s more predominate on the passenger side front. The car has 67,000 miles on it and the tires are the original but appear to be in good shape. The car has also been if for an alignment. What do you think I should try next? -- J.G., E-mail

A: J.G., you could be on to something with regards to your tires. Even though they may look okay to the eye, I would have them checked for balance, and maybe even have them checked for road force variation. Of course, before that, make sure that they have been set to the proper inflation pressure.

The reason I suggest having your tires checked for road force variation is because most wheel balancers only correct for balance while free-spinning the tire. A road force variation wheel balancer places a large roller against the tire’s tread area and measures for variations in the tire’s spring-like force against the roller. To find a repair facility that can check your tires for road force variation, visit www.gsp9700.com and click on “Locate a GSP9700.”

If the tires are ruled out as the source of your trouble, have your Intrigue’s suspension and steering system checked for loose or worn parts like the ball-joints or tie-rod ends.

Q: I own a 1996 Chevy Blazer. It has a problem that nobody has been able to help me with. There’s a strange water-like gurgling noise coming from the dashboard area whenever I accelerate. Also, there’s a problem with the heater. It won’t let me switch modes. I need the heater and defroster for the winter. Do you have any thoughts about what could be wrong? -- K.C., South Chicago Heights

A: K.C., as for the water gurgling noise, it’s possible that there’s water sloshing around inside your Blazer’s HVAC housing. At the lower end of this housing is a drain that allows water to drain outside the vehicle. The drain could be plugged up with debris.

There is a Technical Service Bulletin (#02-08-57-004) that addresses issues regarding water accumulating in the HVAC housing. As for not being able to switch modes, there could be a problem with the vacuum hose between the engine and the mode control vacuum switch. Your Blazer uses vacuum actuators to switch the airflow from one mode to another. Usually, a problem with the vacuum supply hose results in the system going into defrost mode as a safety feature. To have these problems fixed, take your Blazer to a repair facility that employs a technician who is ASE-certified in category A7 (Automotive Heating and Air Conditioning).

Q: Do you know if Dodge is still planning on producing the Challenger? -- L.R., Chicago

A: L.R., yes, they are. The production version will be unveiled next month at the Chicago Auto Show.

AutoAdviser: Ira Siegel is an Automotive Instructor and ASE Certified Master Auto Technician. If you have auto-related questions for Ira Siegel you can call and leave your questions at the Auto Adviser Hotline at 708-633-6839 or e-mail a question to Autoadvisr@aol.com.