When the weather is cold, there is a tapping noise from the engine area on acceleration. Now that the weather is warmer, I don't hear it. What could it be? My mechanic told me it would cost $1,500 or more to tear the engine apart to diagnose. I don't want to spend that kind of money for exploratory surgery. Any advice?
My car has 185000 miles.
My car has an automatic transmission.
Hi there. The noise could be from the lifters not filling up with engine oil until the engine is warm or the pistons have too much clearance causing a condition called "piston slap". Check to see what brand of engine oil and the viscosity (thickness) of the engine oil is being used in cold weather. If you are having 5W-20 engine oil viscosity then I recommend using 0W-20 engine oil during the winter days for start up. This is recommended for your vehicle and also is the main temperature rating for cold weather.
If your engine still is having the tapping noise, then I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose the source of the noise.