2000 Chrysler Concorde Q&A
2000 Chrysler Concorde Question: My car will not idle fast enough. Is this an easy fix?
It is idling at or below 5000 rpms and will die when sitting still. Drives great going down the road. Just had new H2O pump put on and timing belt. - Visitor
5000 RPM is way to high, an engine should idle at 500 to 700RPMs. A lot of big work was just recently done on your car, I suspect some vacuum hose or electrical connector was inadvertently knocked off causing your idle problem. The idle speed is electronically controlled on your car by the computer in your car but even it does not have the scope to raise the idle if there is a vacuum leak. Do a visual check in the engine compartment yourself to see if a vacuum hose is off or see if you hear a hissing sound at engine idle when you lift the hood. Is there a Check Engine Light on? Many automotive repair shops have a machine that generates an inert non flammable low pressure smoke that looks similar to cigar smoke. The intake manifold is sealed off, and smoke is put into the engines intake manifold. The smoke then fills the engines crankcase and if there are any vacuum leaks from gaskets, hoses, or housing smoke emits from the source of the leak. Some mechanics will use propane or aerosol carburetor cleaner, with the engine running they will spray the cleaner or propane around the intake manifold and vacuum hoses. A leak will cause a "lean mixture" condition, when the flammable fuel (carburetor cleaner or propane) comes in contact with the source of the vacuum leak the engine idle speed will raise as the engine has received "fuel". this method of finding a vacuum leak works but is not recommended as it can easily cause a fire. Even just having a professional grade scan tool attached to your car will retrieve live sensor data that may indicate where the problem really is, for example if the fuel trim data shows adding fuel by 15% or so there is likely to be a leak, if it does not show "adding fuel" there is probably not a vacuum leak but its hard to give advice without being able to do first hand basic tests. - patrick mannion