I hear a rattle sound when I accelerate in my lincoln town car

The electronics and modules will tell the reason. It sounds like a computer network issue. You need a mobile auto electrician with a pro grade scan tool computer.

https://www.google.com/search?q=mobile+auto+electrician+near+me

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First try a higher octane of fuel and check the timing.

I would replace the intake asap if you already have a replacement. Is there coolent in the oil or a milky looking stuff in the oil or on the oil filler cap. Your piston rod bearings do not like coolant and can go bad very fast if there is coolent in the oil. That could be the sound you are hearing.

check oil pressure ...lifters may need to be adjusted also change oil

check water pump bearings Check power steering bearings. Check fan belt for condition and tension.

Please remove the acceleration parts and clean it and fix those again, which may solve your problem. The problem might be block in the valves or any damage parts. Please check once, clean it and replace if any parts damaged and try driving.
Thanks

hi Rachel.
see if this helps you out.
https://www.cargurus.com/Cars/Discussion-c2620_ds638555
or this one.
97 towncar engine noise under acceleration Lincolns OnLine Message Forum
Lincoln town car Rattling ticking noise Is the lifter valve making this...
Engine makes ticking noise when accelerating Lincoln Town Car Google Search

could be a ball joint worn out or a spring coil broken

Have you checked your belts? A piece of belt may have come off and been slapping under your hood, and then fell off completely. While it was slapping, your computer would have detected the slow down of pulleys etc. and caused your engine light to come on. Then when the piece broke off, everything would be back to normal. Let me know!

it is big end bearing.