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.

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?

Don’t ask here! Everyone here believes timing chains last the life of the engine!


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!!

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.

make sure you replace any of the timing chain tensioners and guides

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.

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.

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.

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?

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.

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.

I think you are probably in over your head a little on this DIY repair. The timing chain does not normally break easily due to their design and construction. What is the condition of the timing sprocket? What is the sprocket made of? If the timing chain or sprocket came apart then the oil pan will have to be removed to take out chunks of debris related to the failure. I would also pull the engine head to check for any damage related to the timing chain failure specifically the intake and exhaust valves. How high was the engine rpm when the chain/sprocket failed? A timing chain failure is rare so something caused it to fail. I suggest you at least have a good mechanic inspect the engine before you put a lot of time and effort into a possible “boat anchor”. Your vehicle was equipped with a 2.2 but it’s not a stellar engine. Hope this helps.

  1. Remove the valve cover and check valve lash.
  2. Look for sludge on the valvetrain while the cover is off.
  3. Might be a good time to also replace the water pump.

I don’t think you can remove the chain WITHOUT removing the pan anyways…

According to what I found doing a 15 second search…this engine IS a interference engine.

There is very very little chance that one or more valves didn’t get damaged. You can assume that the valves didn’t get bent…and replace the chain…but then if you find out a valve or two or three or more are bent then you did all that work for nothing.

If you don’t feel comfortable removing the head and sending it to a machine shop to fix the valves…then either take it someplace to have it done or walk away.

A quick look at the net shows the 2.2 is an inteference fit engine if the info is to be believed. This means bent valves and a major decision is looming.
There are several methods for determining this for sure. Line the cam sprocket up where the valves are (theoretically) closed on a certain cylinder, apply air pressure, and note if it hisses out the intake, remove the valve cover and check for excessive valve lash, etc.

At this point you need to verify engine damage beyond any doubt before spending one dime on parts.

You bought the car used and depending on your driving habits and environmental conditions going 6k miles between oil changes may be way too long. This can contribute to oil sludging or coking and it doesn’t take much of this to damage a chain, tensioner, and quite a few other things. Removal of the valve cover could reveal some degree of this.

Chains do not take to dirty oil very well. As a motorcyclist I can tell you that the No. 50 chains on my Harleys are good for about 7k miles and O-ring chains maybe 10k miles+ although these drive chains are exposed to the elements.

You can if you’d like confirm whether or not there’s valve stem damage before going through all the work by a simple test. One cylinder at a time, turn the camshaft until both valves are close. Do a pressure leakdown test. If the cylinder holds air, the valves are good.

When doing this, if a piston taps a valve, simply turn the crank a bit to get the piston further down the cylinder so you can continue turning the camshaft to where the valves are closed. You won’t be applying enough pressure turning the parts by hand to do any damage.

Shop around for a salvage yard engine with as low miles as you can find. Have someone install it for you. That’s about your only option at this point. This will be FAR cheaper that trying to repair YOUR engine…In the end, it might be better just to walk away from this one…

I hooked up a compression gauge to all four cylinders (one at a time obviously), and cranked the engine over a few seconds.

Cylinder 1: 50 psi
Cylinder 2: 110 psi
Cylinder 3 & 4: 0 psi.

Does this mean I don’t need to bother with taking the head off? Can I just assume based on this that my valves are damaged (and possibly other things too)? Is it time to throw in the towel?

Have you replaced the chain???

If not then you can NOT run a compression test…it won’t work.

MikeinNH is correct; a compression test is meaningless on an engine with a broken chain or belt.

Do this. Remove the valve cover and rotate the camshaft until both lobes on the Number One cylinder are pointing away from any cam follower or rocker mechanism. This should mean the valves are closed on that cylinder. Rotate the crankshaft until the piston is at either the top or bottom of its stroke. (This will prevent crankshaft rotation if compressed air is applied and the top is better; less air is needed for any test.)

If you do not have a means of applying compressed air (compressor or even an air tank) in a pinch you can stuff a tight fitting hose into the spark plug hole and blow through it. You should be able to huff enough air to possibly detect any air leakage back through the intake and throttle body.
Another somewhat hokey method (if you’re a smoker) is to blow some cigarette smoke through that hose and nose if smoke is rolling back out past the throttle body plate.

The exhaust valves will seldom ever bend as the valve heads are almost always smaller than the intakes so do not worry about listening for air leakage out the exhaust.