Maybe I'm just being paranoid but it sounded very real. So I've been having this misfire issues for a while after the car warms up and the restricted performance message on. Today I decided to spray and clean the throttle body and unplug and clean a few connectors from it. I put it all back together and started the engine and it started right up, I then revved the engine with the throttle cable and noticed that on deceleration there was a faint rattle (about 4 fast repeating knocks/rattles) coming from the engine. There was no misfires or anything but it did this all 5 times i reved the engine during deceleration. However the engine seems to be idling very smooth. I turned off the car and came back to it about 30 minutes later and tried to duplicate the issue but this time it didnt rattle. Does that sound like the dreaded chain tensioner issue?

 

If there is any doubt that the secondary tensioners have NOT been changed then you should not risk ANY use until checked and if necessary changed.
I WOULD be paranoid.
It is not so dreaded if they have NOT failed, but will be dreaded if they do fail.
Check and do, 4 hours at home 1st time. Not to hard to do the top tensioners and gives you a chance to do plugs and gaskets too if necessary.

 

No, that's not it... doesn't mean your tensioners don't need replacing, though.

 

Did you do this from the engine being cold? If so the oil may not have circulated fully and that is what may have caused the rattle.

 

I agree with the previous posters about checking the tensioners, but if it is running nicely, with no rattles at the moment, I think you should be ok. The rattles might be an result of the cleaning fluid used on the throttle body. When the engine decelerates after revving up, there is a high vacuum in inlet manifold, causing the excess cleaning fluid to vopourise, enter the combustion chamber and detonate.

good luck
Pete