Ratcheting noise on startup

Could be the noise for the chain would be around the belts. It would be a rattle type noise. How many miles on vehicle

There is a tensioner and being loose is not as bad as wear, you might notice some backfire noise when the wear gets excessive.

double posted but this time the CAM pops up.
why not read the FSM first. ? linked below.
or alldata.com . log in and read.

here ill do a paste from JUST install PART chapter.
you are doing ALL THAT book free, REALLY?
https://www.techauthority.com/en-US/Pages/Home.aspx

1. Using a vise, lightly compress the secondary chain tensioner piston until the piston step is flush with the tensioner body. Using a pin or suitable tool, release ratchet pawl by pulling pawl back against spring force through access hole on side of tensioner.
2. While continuing to hold pawl back, Push ratchet device to approximately 2 mm from the tensioner body. Install Special Tool 8514 lock pin into hole on front of tensioner. Slowly open vise to transfer piston spring force to lock pin.
3. Position primary chain tensioner over oil pump and insert bolts into lower two holes on tensioner bracket. Tighten bolts to 250 inch lbs. (28 Nm).
4. Install right side chain tensioner arm. Install Torx®bolt. Tighten Torx®bolt to 250 inch lbs. (28 Nm). CAUTION The silver bolts retain the guides to the cylinder heads and the black bolts retain the guides to the engine block.
5. Install the left side chain guide. Tighten the bolts to 250 inch lbs. (28 Nm).
6. Install left side chain tensioner arm, and Torx®bolt. Tighten Torx®bolt to 250 inch lbs. (28 Nm).
7. Install the right side chain guide. Tighten the bolts to 250 inch lbs. (28 Nm).
8. Install both secondary chains onto the idler sprocket. Align two plated links on the secondary chains to be visible through the two lower openings on the idler sprocket (4 o'clock and 8 o'clock). Once the secondary timing chains are installed, position special tool 8429 to hold chains in place for installation.
9. Align primary chain double plated links with the timing mark at 12 o'clock on the idler sprocket.
10. Align the primary chain single plated link with the timing mark at 6 o'clock on the crankshaft sprocket.
11. Lubricate idler shaft and bushings with clean engine oil. NOTE The idler sprocket must be timed to the counterbalance shaft drive gear before the idler sprocket is fully seated.
12. Install all chains, crankshaft sprocket, and idler sprocket as an assembly . After guiding both secondary chains through the block and cylinder head openings, affix chains with a elastic strap or equivalent. This will maintain tension on chains to aid in installation. Align the timing mark on the idler sprocket gear to the timing mark on the counterbalance shaft drive gear, then seat idler sprocket fully . Before installing idler sprocket bolt, lubricate washer with oil, and tighten idler sprocket assembly retaining bolt to 25 ft. lbs. (34 Nm). NOTE It will be necessary to slightly rotate camshafts for sprocket installation.
13. Align left camshaft sprocket "L" dot to plated link on chain.
14. Align right camshaft sprocket "R" dot to plated link on chain. CAUTION Remove excess oil from the camshaft sprocket bolt. Failure to do so can result in over torque of bolt resulting in bolt failure.
15. Remove Special Tool 8429, then attach both sprockets to camshafts. Remove excess oil from bolts, then Install sprocket bolts, but do not tighten at this time.
16. Verify that all plated links are aligned with the marks on all sprockets and the "V6" marks on camshaft sprockets are at the 12 o'clock position. CAUTION Ensure the plate between the left secondary chain tensioner and block is correctly installed.
17. Install both secondary chain tensioners. Tighten bolts to 250 inch lbs. (28 Nm). NOTE Left and right secondary chain tensioners are not common.
18. Remove all locking pins from tensioners. CAUTION After pulling locking pins out of each tensioner, DO NOT manually extend the tensioner(s) ratchet. Doing so will over tension the chains, resulting in noise and/or high timing chain loads.
19. Using Special Tool 6958, Spanner with Adaptor Pins 8346, tighten left and right . camshaft sprocket bolts to 90 ft. lbs. (122 Nm).
20. Rotate engine two full revolutions. Verify timing marks are at the follow locations: ² primary chain idler sprocket dot is at 12 o'clock ² primary chain crankshaft sprocket dot is at 6 o'clock ² secondary chain camshaft sprockets "V6" marks are at 12 o'clock ² counter balancer shaft drive gear dot is aligned to the idler sprocket gear dot.
21. Lubricate all three chains with engine oil.
22. After installing all chains, it is recommended that the idler gear end play be checked. The end play must be within mm 0.004-0.010 inches (0.10-0.25). If not within specification, the idler gear must be replaced.
23. Install timing chain cover and crankshaft damper.
24. Install cylinder head covers. NOTE Before installing threaded plug in right cylinder head, the plug must be coated with sealant to prevent leaks.
25. Coat the large threaded access plug with Mopar® Thread Sealant with Teflon, then install into the right cylinder head and tighten to 60 ft. lbs. (81 Nm).
26. Install the oil fill housing.
27. Install access plug in left cylinder head.
28. Install power steering pump.
29. Fill cooling system.
30. Connect negative cable to battery.

If this is a 4cyl., check the drive belt tensioner first, there is a TSB for a tensioner rattle that is a common failure . To test , remove the drive belt and start the engine and see if the noise is gone,

Have it checked for a bad timing chain tensioner. It's very common on startup

The timing chain tensioner is self adjusting.....Here is some info you can read...

Could be somethin with the timing chain. What engine is in your mustang? Is it OHV or OHC? If its ohv then you could have a lifter tapping.

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1. Remove the engine front cover. For additional information, refer to Engine Front Cover in this section.

1. Remove the crankshaft sensor ring from the crankshaft.

1. Rotate the crankshaft until the timing mark on the RH camshaft sprocket is approximately at the 11 o'clock position and the timing mark on the LH camshaft sprocket is approximately at the 12 o'clock position.

1. Using the special tool, position the crankshaft as shown.
   

1. Install the special tool.

1. NOTE: LH shown; RH similar.
   Remove the two bolts, the timing chain tensioner and tensioner arm.

1. Remove the LH and RH timing chains and the crankshaft sprockets.
   
   • Remove the special tool from the crankshaft.
   • Remove the timing chains from the camshaft sprockets.
   • Remove the right and left timing chains and the crankshaft sprocket from the crankshaft.

1. CAUTION: The bolts are different lengths and must be returned to their original location.
   NOTE: LH shown; RH similar.
   Remove the bolts and the timing chain guides.

Installation

1. CAUTION: Timing chain procedures must be followed exactly or damage to valves and pistons will result.
   CAUTION: Do not compress the ratchet assembly. This will damage the ratchet assembly.
   Compress the tensioner plunger, using an edge of a vise.

1. Using a small screwdriver or pick, push back and hold the ratchet mechanism.

1. While holding the ratchet mechanism, push the ratchet arm back into the tensioner housing.

1. Install a paper clip into the hole in the tensioner housing to hold the ratchet assembly and plunger in during installation.

1. Remove the tensioner from the vise.

1. NOTE: There are 61 links in the timing chain.
   If the copper links are not visible, mark two links on one end and one link on the other end, and use as timing marks.

1. Install the timing chain guides.

1. Using the special tool, verify correct crankshaft position.
   • Remove the special tool.

1. NOTE: Crankshaft sprockets are identical. They can only be installed one way. Refer to the following illustration for correct crankshaft sprocket installation.
   If removed, install LH and RH crankshaft sprockets.

1. Install the LH timing chain onto the crankshaft sprocket, aligning the one copper (marked) link on the timing chain with the slot on the crankshaft sprocket.

1. Position the LH timing chain on the camshaft sprocket with the two copper (marked) chain links and the camshaft sprocket timing mark aligned.

1. Position the RH (outer) timing chain on the crankshaft sprocket, aligning the copper (marked) link with the timing mark on the sprocket.

1. Position the RH timing chain on the camshaft sprocket. Make sure the two copper (marked) links align with the camshaft sprocket timing mark.

1. NOTE: LH shown; RH similar.
   Position the tensioner arms and tensioners, and install the bolts.

1. Remove the tensioner retaining clip.

1. As a post-check, verify correct alignment of all timing marks.

1. Remove the special tool.

1. Position the crankshaft sensor ring on the crankshaft.

1. Install the engine front cover. For additional information, refer to Engine Front Cover in this section.

You 98 Corolla has a timing chain that it internal and need no normal maintenance. It uses a hydraulic/spring tensioner to keep things tight and as long as its quiet, everything is fine.
Your drive belt (not to be confused with a t. belt) is the external belt you see on the passenger side of the engine. It drives you alt, water pump, A/C and power steering. It uses a spring loaded tensioner to keep the belt tight. These can weaken over time and cause a rattle noise and belt slippage.

these 3.3l engines are equipped with timing chains. if vehicle has prolonged down time, typically more than 4 hours, vehicle makes a chatter until the timing chain tensioners put tension on the chain. you will need them replaced.