Q: My serpentine belt came undone but it isn’t showing tear and wear. What made it come undone completely?

Virtually all vehicles from the 1987 model year to the present day have an OBD system (https://www.yourmechanic.com/article/what-is-the-on-board-diagnostics-obd-system). Some earlier model year vehicles, but not all, have some semblance of an OBD system. However, their diagnostic abilities are severely limited. There...

The airbag light indicates a malfunction in the system. The system is always monitored for faults. It could be the airbag itself, wiring, or the impact sensors. The system will need scanned to see what trouble code is set. If...

The old Northstar motors were horrible. They blew head gaskets. Eventually, they made them better, but they are very complex V8 engines with all kinds of computer controls on them and they cost a fortune to fix. So if you...

While the engine is running and the air conditioning system is commanded on, both cooling fans in the assembly should be powered on. The vehicle will turn the air conditioning compressor on and off depending on the system load in...

Check the fuse for the heater/AC blower motor (https://www.yourmechanic.com/services/heater-blower-motor-replacement). If the fuse is good, then either the blower motor resistor or the blower motor itself is suspect. The blower motor resistor provides for multiple speeds for the blower motor. A...

Hi there. It sounds like there could be a serious transmission issue at hand. However, there are a few other possibilities: a broken shifter cable or switch assembly. Does the gear indicator change when the shifter is moved? If not,...

Based on the symptoms you described, it is possible that your ignition switch may be having some issues. I would recommend having the ignition switch tested by a qualified professional to determine if it is functioning properly. If the ignition...

Hello, and thank you for writing in. With such dramatic failures and so many opinions, it is easy to become confused and worried. Checking the oil at this point will not tell you much. Any metal shavings that have come...

Hi there. If the code cleared, it's possible that the source of the code is actually the wiring harness attached to the speed sensor. If the light comes back on, you might want to have a professional mechanic come to...