2 Answers

See a mechanic after reading this too hard normally the marks are on the crankshaft ..

What is a timing chain?
The timing chain is the chain that runs from your engine's crankshaft to the camshaft thus controlling how your pistons or valves fire or rotate. When your engine's crank turns, it then turns or rotates the chain which then turns your camshaft. The spinning of your camshaft is what causes your pistons to move up and down. The chain is very important because it's the only connection between the crankshaft and camshaft and it's vital to having properly functioning valves. Some vehicles do not have a chain. They will use a timing belt or timing gears instead, but they all work in the same fashion.

How do I know if I have a timing chain versus a timing belt?
The best way to find out if you have a timing chain is to look at the front of your engine to verify what is connecting the crankshaft to the camshaft. It looks like a large, sturdy bicycle chain which runs from the lower center of your engine block up towards the location of the alternator but not placed quite as high. Typical application is a belt or a chain. In cars like Volkswagen, you may see timing gears instead. Some engine compartments make it extremely difficult to access or even see your timing assembly. In that case, consult your vehicle's owner manual or call your dealer.

What's the best way to maintain the timing chain?
This is where the timing chain differs dramatically from the timing belt. Timing belts can't be conditioned or maintained, just replaced. Timing chains need consistent maintenance and supervision. They should be oiled or lubed on a regular basis and have the tension checked to ensure it's adequate. Your manufacturer has a recommended timing chain maintenance schedule which can usually be found in your owner's manual. Timing chain lubricant can be purchased at your local auto parts store, but since the chain is usually so difficult to access, it can be a good decision to have your mechanic oil it. Chains don't need replacement like belts, but they can still wear down and go bad.

How do I know if the chain is going bad?
Similar to the timing belt, it's painfully obvious when you have a complete timing chain failure. You won't be able to start or run your vehicle and can face very costly repairs like valve jobs or other expensive engine repair work. That's why it's so important to service the chain as recommended and act immediately at the first sign of problems. Signs to look out for include hesitation while starting the car, a rough idle, misfiring of your valves or pistons, and occasional backfire due to carbon build up from misfiring of the pistons.

How do I replace a timing chain?
Replacement of a timing chain is not an easy task. It was somewhat easier with older cars as it only required removal of the radiator, maybe the battery, and a few other components or belts like the serpentine or fan belt. The difficult part was, and still can be, releasing the tension on the chain so it could be removed and replaced. This required movement and suspension of the engine block to move the crankshaft. In today's vehicles, it is actually more complicated as the timing assemblies are extremely difficult to access and some engines are situated in inverted or other positions in the engine compartment. For those who would like to change the chain themselves, please consult your owner's manual and your local dealership for advice.

Read more: http://www.redlinemotive.com/replacement/infiniti/timingchain.asp#ixzz2GGAvbHXt

13 years ago. Rating: 2
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Go to the local library, get a Chiltons manual, photocopy that page. 

13 years ago. Rating: 1
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