I am not sure where to post this, the mechanical section seems to be full of how-to threads. I need help, as I cannot find the problem I have, so I'll try the general section.

I have a 2.2 ecotec that runs well, with 112K miles. It recently developed a ticking /clunking noise on deceleration while cruising on the freeway 60-65 MPH. If you step on the gas it sounds fine, let off the gas a little and it can be heard. It slowly seemed to get worse, so I changed the timing chain with a kit from autozone.

After changing the timing chain it still makes the same sound, so I took it apart and changed the counterbalance chain with another kit from auto zone.

After changing both chains, the sound is still there. Does anyone know what could be making a ticking/clunking sound only under deceleration?

When I removed the timing chain initially, the fixed guide (vertical) was cracked with evidence of chain contact on the upper bolt head. That was the reason for replacing that chain only initially, because I thought I had found the problem.

I am pretty sure it'* the timing chain that is making the noise, so the cover will have to come off again, but I'm not sure where the problem is? I removed the timing chain tensioner and assured it was extended and I think it is OK, but not absolutely sure. My plan is to take it out again, and take it to the local chevy dealer parts counter, hoping someone there can help me out.

I need help determining where this noise is coming from. Is is possible to install one of the timing chain guides upside-down or backwards, in such a manor, it will go back together, and run OK, but still make the noise I have?

dont know that much about that engine but some thoughts about what else might be causing your noise, if it only does it on the highway it may be trans related like lq bolts or fly wheel bolts, or just happens to resonate some cover at that particular speed, i have had drive shafts do that as they where they start wearing they dont pivot like they are supposed to. i think i would put it up on stands and see if i can get someone to replicate the problem while watching the shafts and listening for what area it is in

It is an A4 transmission. If you put it in 1st gear and slowly accelerate, everything is fine until it gets to 2500 RPM, when it rattles badly, shift to second and slowly accelerate to 2500 RPM and it rattles badly, at RPM'* below 2500 RPM it is fine. The reason it rattles at highway speeds is the cruise RPM is about 2100-2200 RPM, approaching the magic 2500 RPM when it sounds like something is going to break. I just replaced all these parts and it rattles badly, I'm thinking it may be a bad tensioner. Or I am missing something, I hate to pull the cover again, it'* a pain, but I don't know what else to do? Could I have a bad tensioner? It'* easy to replace, so it is tempting to try it before removing the cover again.

some engines are externally balanced too, if something happened to the weights on the flywheel or something happened to the balancer, sometimes those start coming apart or separating or cracking.

The engine runs fine, except when the timing chain slaps and rattles. I seriously doubt it is anything other that the timing chain.

I went back to the auto parts store where my parts were purchased, Advanced, not AutoZone, (I mistakenly said AutoZone in my initial post). I showed him a thread I found on the net (see below) where others had trouble with the old style tensioner, which was the one supplied in my kit. The guy was real nice a did a search and found the new (C-clip) style tensioner at the warehouse (it has been discontinued). He ordered one and I had it the next day. I installed the C-clip style tensioner without removing the valve cover (so I didn't strike the chain too fully extent the tensioner), and drove it to work. It is still rattling, so it did not fix it. I am going to pull the valve cover today and see if the new tensioner is fully extended, or still in the collapsed (shipped) position. Before I got this new style tensioner, I pulled the old tensioner, fully extended it, and reinstalled it, and the chain still rattled. Is it possible that when I reinstalled it, it went back to the collapsed position? When I did this install initially I did use a long screwdriver with a rag on the tip to strike the chain/tensioner to unlock it, or extend it. I am wondering if I was successful in extending it, because it is hard to see it. Like I said, I am going to pull the valve cover today and see if I can verify whether or not it is installed in the extended position or collapsed (shipped) position.

Anyway, this timing chain is still giving me problems, but I have not given up.

http://www.chevytalk.org/fusionbb/sh...hp?tid/219345/

2.2 Ecotec 4 cyl fix. - ChevyTalk --The Social Network for Chevy Fans