When my cobalt is running it's making a odd sound kinda sound from the left side of the motor. Not quite as loud as when you cold start it the timing chain. It just sounds like the chain is rolling. Checked the oil and it's good. Even added some to see if it'd fix the problem. Any ideas?
3 possibilities here, your chain is stretched to the point where the tensioner can't keep it tight anymore or hopefully it's just your tensioner that has failed like mine did. Check the head of the tensioner for a bump instead of a flat surface. If it is flat it should be changed anyways. If it doesn't fix the problem then chances are the chain has stretched or it's the waterpump/balance chain tensioner in which case you will need to remove the front cover to change or check.
You don't need to pull the timing cover for the cam chain tensioner. Pull valve cover to see if there's slack. If there is, the tensioner is on the back of the head. You can take it off with any 1 1/4 wrench or socket, but make sure to ziptie the chain on the sprockets before you do it
There are 2 chain tensioners, if you hear the chain rattle on cold starts chances are it's your timing chain tensioner. You can access it from the back of the block.
First style tensioner was prone to failure. Pictured above is the old style. New one has a bump on head and plunger is held in place with C-clip and cannot fall in.
I just noticed some chain noise a few days ago briefly at cold start up. I'm guessing I'll need to replace the tensioner. I have an '05 with 117k miles. Ive seen some threads on here with instructions but the job looks a bit intimidating. I changed out my water pump on my '97 grand am gt back in the day. I remember having issues resetting the timing chain tensioner. I'm just dreading doing this job. Is it difficult? Can anyone guesstimate how long this job takes? I've priced the tensioner. They aren't too expensive. I'm just wondering what else I need to buy? Any new gaskets, guides, seals? I want to make sure I'll have anything is need to get it back together once I've opened it up. Maybe I'll call the shop and get a price on just having it done.
It took me about 20 minutes. The valve cover gasket is reusable. All you will need is 2 tie-raps to hold the chain in place while you remove the old one, then with the new one in place you just have to push on the guide where it touches the tip of the tensioner to release it from its preset to preload the chain. Remove the ties, reinstall cover and coils, torque bolts and start the car to hear nothing but a purr.
I hear mine a little bit too on start up, maybe 5-10 seconds, it usually goes away, and sometimes stays on for a minute. Is there a guide on here to see how to do it so I can see if I can try and tackle it or ship it out?
I noticed at idle (650+-) the motor kinda shakes a little. Im assuming this has somthing to do with that. (motor and transmission mounts are new)
Rough idle is probably your throttle body that's dirty. As for changing the tensionner I think there's a DIY. Maybe not but it's fairly simple.
1. Disconnect the wires going the ignition coils
2. Unbolt the ignition coils.
3. Unbolt the valve cover and remove being carefull of the seal.
4. Tie-wrap the timing chain to the cam sprockets.
5. Remove the old tensionner.
6. Install new tensionner.
7. Release new tensionner by pressing on plastic guide at the tensionner.
8. Remove tie-wrap.
9. Re-install cover and coils. Torque specs are listed somewhere on here, if you can't find them with search box let me know.
On a newer car, where you are pretty sure the chain isn't stretched too much yes I imagine you could just swap the tensionner. But on an older higher mileage car, don't know if I would take the chance on having the chain jump a cog.
Would aggressive driving and high revving wear out the chain/tensioner/guides etc. prematurely? I've got 120,500kms (75k miles) on my motor and she's clicking at me when below optimal operating temperature.
the stealer said they wouldnt just change the tensioner, they have to change the whole thing(epic bullshit), and they said $650 with parts and labor. If i needed the whole thing done, I honestly dont think thats that bad (for the dealer), but still..
welp, I got the tensioner changed, and Im glad I didnt do it myself. Turn out to jump a cog on startup, so theyre redoing the timing now. Yay life:notrust:
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