Every now and then I can hear a rattling and clattering sound when starting the engine (2008 2.4L with 110’000 km). It seems to happen more often when it’s cold outside, but rarely more than once or twice a month. I have read through all the 17 pages of the sticky "How To" describing the timing chain tensioner replacement, but now I am not sure anymore whether to replace it and if yes, how.

From what I can tell when looking at the engine, the currently installed tensioner seems to be already of the new design with the thicker bolt (full of rust though…).

• Should I replace the tensioner with a new one (ACDelco 12608580) to fix the rattle or could it be something else causing the rattle?
• Should I take it out without removing the valve cover and without blocking the chain from moving?
• Should I put the new one in with the piston retracted or already protruded?
• Should I put in a new chain together with the new tensioner or can I leave the old chain in?

 

I’d recommend replacing both chains and all guides and tensioners. At that mileage throw in a new water pump.

 

That mileage is only around 70,000 miles ? Not sure about recommending chains and water pump just yet. Maybe just try a new tensioner.

 

Mine was making noise at 110,000 klms or 70,000 miles , I changed just the tensioner, the noise deminished, but the front chain guide was the culprit.
Better to change it out if it’s making noise.
Just from my experience with Oldblue.
As for changing out the tensioner, I did that with the valve cover on , the tensioner as it came outta the box , it released in the tensioner guide without having to use any drift or punch. You’ll need a 32 mm socket and a 24 inch breaker bar , the torque is 55 ft lbs.

 

I would buy the chain kit and only install the tensioner to see if that helps. You might be the lucky one, more likely the guides are shot.

The 2.4 L has the "new" type tensioner from the factory. The book says to give it a sharp wack to depress it 2mm.

 

Just wondering is the 08 2.2 different?
i am creeping up on 205000 k. No noises to worry about other than whay I was thinking a starter when starting. Just seems to make noise once starting up and I attributed it to the starter drive releasing and bushings allowing it to rattle. Starts perfect at -30 still.

 

Only difference is the 2008 2.4 has Varible Valve Timing and the 2008 2.2 doesn’t
At your 200,000 klms , I recommend changing out the two chains , guides , tensioners and the water pump whilst you have your hands dirty. The tensioner might already be the new style, simply have a look either reach down the head on the passenger side, is that larger bolt flat or does it have the distinctive hump? A mirror can also be used





The one on the left is the new style tensioner


I highly recommend getting one of these for the front timing chain guide the flimsy little bolt can break and the guide gets chewed up

 

Many thanks for all the valuable input. For replacing both chains and all guides and tensioners, would that be numbers 17 to 22?:

https://www.newgmparts.com/auto-part...at/engine-scat

donbrew mentioned a chain kit. Would that be a specific part number including all the necessary parts?

 

Cloyes 9-4201SX for the timing chain




and 9-4202SX for the water pump balance shaft chain.




These kits do not include the sprockets, because those aren’t for the VVT engines