Dear Motor Medics,
I heard you guys on a recent show discussing vehicle warm-up times and heard you say it was not necessary to warm up a fuel injected vehicle. I thought that all vehicles should be warmed up to get the oil flowing at least a little bit. If this is so, how long is a good warm-up time?
Brandon in Dayton, Ohio
Dear Brandon,
There was more to what we were talking about that you must have missed. While we said that the fuel injected vehicles manufactured in the past few years could be driven right away due to better parts and efficient injection systems we still recommend some warm up time. We have heard some people even say just start them up and drive them to warm them up faster although we don’t agree with that. There has to be a proper medium between running a vehicle too long to warm it up which wastes fuel and taking off so soon that the defroster won’t even keep a windshield clear posing a safety hazard. The owner’s manual will provide a good reference for warm ups. For us personally we tend to err on the longer side of warm up times. We like to make sure everything is lubricated and working as it should. It also gives us a chance to do some important things like adjust those mirrors, fasten our seat belts, and most importantly, turn off our cell phones for safety.
Take care, the Motor Medics
Dear Motor Medics,
My question is about accessories plugged into a lighter socket. Recently I have been experiencing dead batteries on my 2009 Cadillac Escalade and they tell me it’s caused by the accessories that I leave plugged into the lighter at all times. If the vehicle is not driven every day it will not start and is completely dead. I question how something as small as a cell phone or GPS unit can drain a battery so quickly, is this possible? I have stopped leaving things plugged in and have had no further issues but wonder if it’s not just a weak battery. What are your thoughts?
Darla in Elmira, New York
Dear Darla,
It may sound strange but when anything is left plugged into the accessory outlet it can run the battery dead. Yes the power drain is very small and would take many days to drain a battery but there is something much larger at work here. Newer vehicles have many modules that when awake (turned on) will draw several amps of power and would drain a battery very quickly. To prevent this drain the modules go into a sleep state just like a home computer in sleep mode. They know when to sleep by monitoring the systems for non-use just like a home computer. If something is being charged by the lighter socket they think the system is still in use and keep the modules powered thus draining the battery quickly.
Take care, the Motor Medics