I haven't been on the forum in a while, but just learned a HARD lesson about the timing chain guides. My '07 was rattling at start up since the spring time, first once a week, then once or twice and eventually every time I started it. I knew it wasn't normal, but it started happening so often I thought maybe it WAS normal. It went away after a minute of driving, after all!

On October 16 the car went in the shop because the CEL came on and the error code was a bad camshaft position sensor. Turned out the sensor was fine, it was the rapidly degrading timing chain, guides and bent valves that were the problem!

The repair is nearly finished, but after nearly a month in the repair shop and $1600 to $2000 to fix the damn thing I encourage any owner to get it inspected AS SOON AS the noise starts. And I'd just paid the damn loan off on the 15th...

 

Kind of like my wife does not associate an odd sound and smell from the vacuum cleaner with a burning belt.

 

the sound you hear from a bad tension thing,does it sound like you are running a zipper up and down

 

More like a rattle that goes away after warmup.

 

my girls cobalt 2.4 has a weird sound for 2 mins after cold weather starting,my 07 hhr 2.2 does not make a sound

 

what yeary is it? my 07 had the old type of tensioner but my 08 with a 2.4 all ready has the new updated version.

 

I believe, but have no actual documentation that the "new" one is used in VVT applications. i.e.: all 2.4L and 2009 on 2.2L and some 2008 2.2L.

 

2006 cobalt,my hhr is an 07

 

Best thing to do is look at it. If it has a bump on it it's the new style.

The one at the bottom of the pic is the new style. The one at the top is the old style.

 

I decided to replace the tensioner. After I read this post.
Today the replacement took place. I did not work myself, I instructed it to a specialist for repair of engines ($ 6 for all).
My old tensioner - a new model, although the car in 2006.
At least not visually different from the new part, which I bought.
But the touch! .. Iron, which I learned from my engine, have a tight spring. I barely pushed it and drizzling oil out of the hole. The new part was not very elastic, the free displacement of one finger.
We pumped it with oil to the point of exhaustion - not much better.
I was afraid that if I stick it in the engine, my chain will not be pressed and to happen big trouble. But dare.
Thank God, everything works fine.
But I'm at a loss. So it should be? Spring new part to be weak?