Timing chain tensioner

SOURCE: Car not running on all cylinders

the first thing that comes to mind is ignition system faults. Are the spark plug wires connected properly, in the right firing order? Has work been done on the distributer, or the engine head, recently? Ignition timing can be 180 degrees out, and the engine will still run, sometimes. If it is not the ignition system, the next most likely culprit is the head gasket, which seals the head to the block of the engine. If this gasket is breached seriously, it can cause a cylinder(s) not to fire. Is there water in the oil, as evidenced by a thick, white foam? Is there oil in the coolant? Either of these are symptoms of a leaking head gasket. 
Basically, one cylinder isnt firing for one of a number of reasons. The most common cause is an igntion fault. This will cause the engine to feel and sound "lumpy", and the power would be greatly reduced. The best way to find the cylinder which is responsible is quite simple but care must be taken. Firstly if you hate electric shocks as much as I do, find a proper pair of electricians insulated pliers, and even some decent rubber gloves if you can aswell. Start the engine, and one at a time, use the pliers to remove a lead from the top of one spark plug, if the engine almost stops, or gets worse in any way, it is not that piston which isnt firing. Repeat the proccess, one at a time, you will know which piston ISNT firing when you remove the plug lead, and there is no change in the engine sound, this is your defective cylinder. Its just a case then of looking at the condition of the spark plug and asessing the cause of the misfire before carrying out repairs. BEWARE:- THE LEADS WHICH CONNECT TO THE SPARK PLUGS CARRY SEVERAL THOUSANDS OF VOLTS - HENCE RUBBER GLOVES AND INSULATED PLIERS 

Ot Tap

• 253 Answers
• Posted on Mar 06, 2009

SOURCE: 2002 Grand AM GT

FUEL PUMP GOING OUT.

Marvin

• 85242 Answers
• Posted on Mar 30, 2009

SOURCE: car starts run's 3 seconds shuts down

Your car is equipped with a system called PASSKEY standard on all GM cars and light trucks, try the following procedure to reset the system, the battery being dead will trigger the system.

PASSKEY LOCKOUT RESET GM CARS 1999 UP
1) Put the key in the ignition and turn to the "ON" position. Leave it that way for 10 minutes. After 10 minutes turn the key and take it out. Repeat this process (2) more times (3 times, 30 minutes total) This should reset the passlock system to recognize your key.

SOURCE: 1998 sunfire 2.2 rattling/knocking noise

There are many other possibilities that are to be checked, other then timing chain and chain tensioner:--- 1) Loose timing chain, bad timing chain tensioner.
2) Bad lifter.
3) Bent valve.
4) Improper timing (piston striking valve).
5) Bad wrist pin.
6) Spinning or corroded rod bearing.
7) Spinning or corroded main bearing.
8) Excessive piston to bore clearance.
9) Excessive bearing to journal clearance, main or rod.
10) Failing oil pump

ALSO it could be a loose flywheel/flexplate bolt.could be lifter knock, or it could be Injector tick. injectors are more noticeable at idle, and lifter knock is all the time loud, unless it's doing it from oil pressure drop, and it might go away with RPM.As you mentioned in your case, that noise disappears at high rpms. ---------- This troubleshooting will help, to locate exact fault paret causing this noise.Thanks.Helpmech.

SOURCE: Car wont stay running, even with foot on the gas.

You could also check the fuel injector wires,sometimes they come loose if the clip broke somehow