Q: Surging idle

Hello. To answer your question, yes, the lack of an air filter (https://www.yourmechanic.com/services/air-filter-replacement) can cause catastrophic engine damage. Over time, the debris will build up inside of the engine as it mixes with air and other carbon contaminates. Eventually, it...

Hi there, and thanks for asking about the problem with your 2016 Lexus RX450H. This doesn't sound like a tank problem, but rather the scenario where the tank includes 2 fuel gauge sensors, and 2 fuel pumps - a fairly...

Hello there, thank you for asking about your 1987 Oldsmobile Toronado. This is something that would require first hand inspection for complete diagnosis. However, there is a technical service bulletin (TSB) that may pertain to your issue. The TSB is...

Hey there. This may very well be a sign of a bad thermostat (https://www.yourmechanic.com/services/thermostat-replacement) or something else such as failing coolant fan relays (https://www.yourmechanic.com/services/cooling-fan-relay-replacement). As you may know, the thermostat regulates the flow of coolant in and out of the...

Hi and thanks for contacting YourMechanic. It won't matter what type of oil was put in the gear box as long as the viscosity was the same. You can try replacing the oil and see if it makes any difference,...

Hi there, thanks for writing in. Typically, a P0420 code (catalyst efficiency insufficient) is the catalytic converter (https://www.yourmechanic.com/services/catalytic-converter-replacement) not properly functioning. Chances are, the Check Engine Light going off and then back on, it's still the P0420 code that is...

Hi there. You might be better served to contact a Mazda shop locally to seek their advice after they inspect your car. The problem with cold air intakes and aftermarket intake systems and that they often negatively impact the sensors,...

Hi - GM V8 ignition control modules from 1987 to 1995 should interchange with your '91 5.7L. For assistance, I recommend a ignition control module replacement (https://www.yourmechanic.com/services/ignition-ignitor-replacement) performed by a mobile, professional mechanic, such as one from YourMechanic, who will...

Sport mode permits gear shifting at higher engine RPM which favors quicker acceleration and more power. There could be some additional wear and tear on the vehicle drive train when using Sport Mode, whether the shifts are automatic or manually...