Clacking on start up

Question edited for clarity.
Question moved to model category.

All of these issues are electronic, you need and auto -electrician that know his way around his $5,000 Pro Grade Scan Tool computer. A mechanic is not the person you need, oil changes, new brakes, new exhaust, engine tune, sure..

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

..

Check the oil. nothing on the dipstick? happens on these 3.4 engines. Also could have way to much brown oil, intake gasket blown. Clacking is the rod bearings. Replace the engine.

well if theres water in it then its either in your oil pan or the engine check ur oil and if u see water then change it quick cause it will cost u alot for engine work check ur air filter if its wet then water got in the engine and you have to get it out in order to do that pull all the sparkplugs out and crank the engine the compression of each cylinder will blow the water out

Sounds like your valve lifters. It's possible that they drained the oil and never refilled it. This does happen when they go on break or lunch half way through a job. They think they added the oil, but did not. Out you go, Mr. Clack-Clack.

I suspect you have hydraulic lifters and the sludgy oil could plug up your lifters - as well as running that low on oil. Top off your oil and get an oil additive engine cleaner, warm your engine at idle only then change oil when warm. Add 1 quart of marvel mystery oil to the crankcase then top off with high mileage oil, like Valvoline. Run motor at idle only and see if this cures the problem - if not then you may need to remove the intake and replace your lifters, a costly and time consuming job. I would not try driving as you may waste the cylinder head or block by running a stuck lifter. There is also an oil additive specifically for stuck lifter and I think I would add that as well as the Marvel.
I hope the quick fix works for you and good luck!!!

It sounds like you have a valve or rocker issue, I would run an engine cleaner through the engine. I suggest draining 1 quart of oil, pour in the cleaner and run engine for 5 min. Let engine cool and drain the oil. Pretty much another oil change. This will hopefully clean a sticking valve if this is the issue. But I also would check for anything hitting the pulley's or fans that may have came loose. I've seen this a lot. Good Luck. It may take 2 cleanings for the engine, so don't get disappointed.

Sounds like an oil pressure problem. The clacking sound is most likely the lifters are collapsing due to loss of oil pressure. You may have a failing oil pump.

If your exhaust smells like sulpher and the exhaust coming out of the tail pipedoes not stop immediately after engine is turned off. Your catalyctic converter is restricted. Have chk'd by muffler shop

Best thing to do is take it in to see if the oil pump is working properly. A oil pump not pumping properly will lead to what people call a "dry valve tap". The moving parts in the engine will make noise when there is no lubrication happening. Especially the parts that are moving the valves. That why they call it " dry valve tap".
Has the engine light stayed on at all?

the intakes go bad on these engines....... they leak coolant in the cylinders and cause a hydro lock that causes the rods to bend making the piston skirt hit the crank......" clicking noise" theres a law suit in progress for this issue......... you can find info on the internet