Expert: Matthew Day - 1/4/2009

Question
'98 V6 Accord. After not driving for 3 weeks we now find engine at idle fluctuates between approx 1200-2000rpm. I have been told this is "get you home mode". Could you advise on possible causes and fixes

Answer
You have one of two problems. Your cooling system could be low to the point the powertrain control module is getting a false signal of weather the engine is cold or warmed up. Take the radiator cap off the radiator while the engine is cold & check it. If it is low, then top it off with mixed antifreeze & take it in to have your cooling system inspected. Next you could have a vacuum leak meaning the engine is sucking in more air than what is required. The idle air control valve on the throttle body is notorious to go bad & cause idle problems. Either way, take it in to a qualified mechanic to have it checked out.