Chrysler Repair: 2000 Chrysler Concord Sounds Like a Diesel, viscosity increase, chrysler concord

Question
Our 2000 Chryler Concord sounds just like a diesel when it is at an idle but immediately goes to a normal sounding engine when you accelerate.  The noise just started and like most noises from an engine, it's hard to determine what part it's coming from.  We just bought the car 7 days ago from a private party and do not know any of it's history.  Thanks for your time.

Lee

Answer
Hi Lee,
I am not that expert on describing or hearing engine noises, but if it sounds like a clicking from the top of the engine (valve cover area) that could be the hydraulic valve adjusters not having sufficient oil pressure due to the oil being too low a wieght, or being diluted with leaked fuel or coolant getting into it, or an oil pump that is not putting out sufficient pressure at idle speeds. You could smell for gas on the dipstick, look for foam which is a sign of coolant leak, and/or feel the oil viscosity with your finger tips, or put a gauge in place of the oil sensor unit and measure the idle oil pressure. It usually should be around 5 psi minimum at idle, but tell me which engine you have if/when you write back. See if you can find out what weight of oil is in the crankcase from the previous owner, then change it and use the next higher weight range in a drain and refill. That will raise the oil pressure at idle.
If the noises sound more like from the engine block that indicates the same sort of problem with oil pressure, so try to correct that situation by viscosity increase, and if that fails do the pressure measurement and then go on from there.
It may be a clogged oil line, or wear and tear on the engine, but hopefully increased viscosity will do the trick.
Roland