Is a 2005 Pontiac Sunfire code f 16 valve engine an interference engine.On these sites the answer comes up 50/50 and a lot of I thinks Is there a GM or Pontiac site that gives a definite answer.

be VERY careful! Most engines are interference motors and a bust timing belt results in catastrophic failure when the valves contact the pistons because they are out of sync!

Timing belts usually come with markings - you would almost certainly find the compression TDC for cylinder 1 (not exhaust TDC - if the air blows thru plug hole when piston is rising its compression - if the air is NOT blowing out plug hole its exhaust tdc - rotate once more).

Now you will have to find the timing marks on the camshaft(s) and set according to the manual.

I found a good answer here with a diagram:
http://pontiacforum.com/pontiac/showthread.php?t=29792

It will on some BMW and Honda engines. These are called interference engines. I dont think any US cars have interference with piston and valves.

i think you need to take the oil pan back off and take a good look at the rod bearings, this engine sounds a lot like upper end noise when the piston is hitting the bottom of the cylinder head because a rod bearing has spun.

Pretty common problem with these. Here's a guide to learn how to fix GM instrument clusters yourself, I used it to fix mine and it worked great.How to guide for Sunfire instrument cluster repair

If it just does it when cold it's piston slap. GM made the skirts shorter to save weight and metal so until they warm up and expand in the walls your piston sill "rattle around" in the sleeve of the block making a "ticking" sound. This is normal but annoying.
If it continues when warm it could be a number of things too numerous to mention.
Try adding Lucas to your engine oil on the next service and see if it goes away.
Switching to a higher grade fuel may also solve your issue. Both cheap fixes.

service engine light/ might have came on because of a fuel cap not being tight enough which sets a code for an EVAP leak

i can't remember what year sunfire's were effected but there was a update to reflash the PCM for a O2 sensor code
if the check engine light comes on it disables the traction control
i know before GM dealers were the only ones with the program to update the PCM
hope this helps

Complete upper dash pad comes off and cluster comes out from the top.

OBD 1.5 OBD 1.5 refers to a partial implementation of OBD-II which General Motors used on some vehicles in 1994 and 1995 (GM did not use the term OBD 1.5 in the documentation for these vehicles - they simply have an OBD and an OBD-II section in the service manual.)
For example, the 94-95 Corvettes have one post-catalyst oxygen sensor (although they have two catalytic converters), and have a subset of the OBD-II codes implemented. For a 1994 Corvette the implemented OBD-II codes are P0116-P0118, P0131-P0135, P0151-P0155, P0158, P0160-P0161, P0171-P0175, P0420, P1114-P1115, P1133, P1153 and P1158.[1]
This hybrid system was present on the GM H-body cars in 94-95, W-body cars (Buick Regal, Chevrolet Lumina ('95 only), Chevrolet Monte Carlo ('95 only), Pontiac Grand Prix, Oldsmobile Cutlass Supreme) in 94-95, L-body (Chevrolet Beretta/Corsica) in 94-95, Y-body (Chevrolet Corvette) in 94-95, on the F-body (Chevrolet Camaro and Pontiac Firebird) in 95 and on the J-Body (Chevrolet Cavalier and Pontiac Sunfire) and N-Body (Buick Skylark, Oldsmobile Achieva, Pontiac Grand Am) in 95.
Depending on the year and the vehicle, a car with the OBD 1.5 system may have either the older OBD-I connector, or the newer OBD-II connector, but they are electrically identical to each other.[citation needed]
The pinout for the ALDL connection on these cars is as follows:
Female OBD connector pinout 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 For ALDL connections, pin 9 is the data stream, pins 4 and 5 are ground and pin 16 is battery voltage.
Additional vehicle-specific diagnostic and control circuits are also available on this connector. For instance, on the Corvette there are interfaces for the Class 2 serial data stream from the PCM, the CCM diagnostic terminal, the radio data stream, the airbag system, the selective ride control system, the low tire pressure warning system and the passive keyless entry system.[2]
An OBD1.5 has also been used on Mitsubishi cars of '95 '97 vintage.
An OBD1.5 has been used in some 1995 Volkswagen VR6's (Juice Box's GTI)