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Q: I have a tapping noise coming from left side of motor on top while pressing the gas on cold starts.

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When I push the gas to accelerate in the morning or during a cold start period I hear a tapping noice only when I push the gas. Has been going on for about 2 months now. Oils never been ran low and I use 2nd grade gas. It idels fine with no taps at all or even revving the engine while in park it still doesn't tap. But if I put it in gear and take off it'll start tapping while I'm pressing the gas.

My car has 197234 miles.
My car has an automatic transmission.

A: Hello. The most common cause of this noise ...

Hello. The most common cause of this noise in your vehicle is a leaking exhaust manifold. It is common for the bolts on the rear of the manifold to break, causing a small leak. Most of the time you will hear it in park, but if the leak is very small you will not hear it until you start driving which puts a larger load on the engine. If the exhaust manifold is fine then it may be caused by a lifter that is collapsing. I would usually pull the valve cover off to inspect the rocker arms for looseness. If it is loose then it may need a lifter. If you plan on having the vehicle looked at as a certified mechanic can come to your home or office to diagnose the source of the sound.

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