At cold start very loud crack metal rattle after warm up at times in drive a metal type vibration rattles can hear over engine noise occasionally it's really loudly when ambient temperature is below 40 can't tell if starter valve piston knock or what or loose heat sheild any thoughts
My car has 86570 miles.
My car has an automatic transmission.
Hi there. This noise can be caused by a few things. Most of the time it is caused by a loose heat shield on the exhaust. When this occurs you will hear the noise as the shield rattles and some of the time it will go away as the exhaust warms up. I have also seen this engine have failures in the timing chain that will cause this. Low engine oil or a bad oil filter can cause this so I will usually change the oil first. If the problem persists then the front of the engine will need to be disassembled to inspect the timing chain. If you are going to have this repaired, consider YourMechanic, as a certified mechanic can come to you to [diagnose why the engine is rattling] https://www.yourmechanic.com/services/loud-squealing-or-rattling-is-coming-from-engine-inspection
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