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Timing Chain Replace

The timing chain broke on my 2002 Pontiac Grand Am 2.2L 4cyl engine. Since the car is 9 years old, has 140K miles, and is worth less than what a mechanic would charge me for the repair, I am replacing it myself. My prior mechanical work ranges form replacing a head gasket to replacing a light bulb in the dash. I have a working knowledge of mechanical things, but not a lot of experience with engines.
<br/> I bought the Haynes AND Chilton?s manuals to assist me in this repair. Both manuals list the procedure for removing the timing chain (and assorted things like the tensioner, etc), and installation. My question is this: If the timing chain is broken, and that?s the only thing that?s broken, do I need to take off all those other things, or can I just slip the new timing chain in place? For instance, do I need to remove and replace the camshaft sprockets?


  • edited August 2010
    Don't ask here! Everyone here believes timing chains last the life of the engine!

  • edited August 2010
    Yes. Not only does the chain wear, the sprockets wear and must be replaced with the chain or the new chain will QUICKLY destroy itself by being run on the worn-out sprockets. Follow the instructions exactly. Any short-cuts here will lead to disaster...

    Because of the very limited amount of room you have to work in, this will not be an easy job..The harmonic balancer will have to be removed from the nose of the crankshaft. This can be very difficult in close quarters..

    Tester, my friend, come on, it's a PONTIAC!!
  • edited August 2010
    I have already found out about the close quarters when I removed the drive belt tensioner. The irritating thing for a novice mechanic like myself is the following (direct quote from Chilton's manual):
    "Remove or disconnect the following: Crankshaft sprocket, Balance shaft drive chain tensioner, Adjustable balance shaft chain guide, Small balance shaft drive chain guide, Upper balance shaft drive chain guide, Balance shaft drive chain."

    Pictures are great, especially ones that label stuff. Unfortunately, I don't know what some of these things are.
    It seems to me that Chiltons are good for people who "used to be mechanics" and just need a reminder, not those of us who are trying to DIY.
  • edited August 2010
    make sure you replace any of the timing chain tensioners and guides
  • edited August 2010
    The first thing you need to do is verify whether this is an interference fit engine or not. If it is, then the intake valves in the cylinder head may be bent and the chain is irrelevant at this point.

    You did not provide any details about this car (bought new or used, how regular the oil changes are, etc.) but it's possible your timing chain was murdered rather than it dying a natural death of old age.
    I think this engine uses an oil pressure operated tensioner with a tiny oil feed port. Runing the engine low on oil, low oil pressure due to a worn engine, oil sludging or coking cutting off feed oil to the tensioner, etc. could be behind this chain failure.
  • edited August 2010
    Check on your engine size again. I don't believe the Grand Am was offered with the 2.2L. If it's a 2002 with a four cylinder, I think it will be either a 2.3 or 2.4, which are overhead cam engines based on the quad four (sometime around 2003, they started using the Ecotec engine, which was also based loosely on the quad four). Those engines are interference engines, so you will need to perform a leakdown test or check your valve lash to determine if you bent your valves. As a side note, a common reason for those engines to lose their timing chains is sludge. If this is the case, you need to track down that problem or the repair won't last very long.

    Edit: Sorry for the redundancy in my post to ok4450's advice. I didn't realize he mentioned a lot of the same things I did regarding lack of oil killing the timing chain, but it is a suggestion worth repeating.
  • edited August 2010
    How would I find out if it's an interference fit engine? It's just the stock engine. I bought this car used in 2005, since then I have changed the oil about every 6K miles. It has had a relatively free life (since I bought it, at least) of very minor repairs. The oil wasn't bad.
  • edited August 2010
    Um. Yep. I checked it again. It's still a 2.2L. It is a DOHC Ecotec. My Chilton's manual lists possible engine sizes for my car at 2.2, 2.4, 3.1 and 3.4. Mine is a 2.2. I don't know if I should be insulted or not that you think my engine doesn't exist ;-p. Are you saying my 2.2L DOHC Ecotec is an "interference engine"?

    And how do I "track down" a sludge problem?
  • edited August 2010
    Ok, so after reading the several responses, so far I have gathered the following:
    1. I need to replace all the timing kit components.
    2. This will not be an easy job.
    3. I might have other problems resulting from the chain going.

    Now, I have more questions:
    1. How do I determine (without disassembling the entire engine)if the valves are shot?
    2. How do I determine if my engine has a problem with "sludge"?
    3. Is there anything else I need to check before putting everything back together and calling the repair "complete"?
    4. Should I simply invest in some C-4 or Semtex and forget the whole thing?

    Edit: The oil I drained from the engine at the start of this process was dark, but clean and didn't look funny, watery, etc. The inside of the engine looks clean as well, not like the pictures I have found of what "engine sludge" looks like.
  • edited August 2010
    If you can get access to ALLDATA, it sometimes provides better step by step instructions and pictures. I can access AllData through computers at my local library.

    A real shop manual may also be better than Haynes for more detail.
This discussion has been closed.