Hello, I have a chevy cobalt and recently just upgraded the pistons and rods. I’ve driven it about 1k miles since the replacement and it just started making a ticking noise. It sounds like its up in the head. I’ve changed my timing chain tensioner bolt, also replaced the rod bearings. Everything lines up at TDC but around 2-3k rpm it starts ticking. I’m also getting a P0300 code. When I pop the hood I hear a leak somewhere but can’t find it. I’ve also tried using carb cleaner at the injectors to see if a gas leak was accruing, but nothing changed in the rpms. At this moment I am out of Ideas and need some help troubleshooting this. Thanks
-Why were the pistons and rods upgraded?
-Was the valve train touched at this time?
-Is the tick at about half the engine RPM (valve train) or faster?
-How loud is it?
-Does the engine run fine?
po300 is a misfire code just googled it and check the egr valve and the cam sensor can also be a coil or plug or an injector may be something simple left loose or disconeted .
Is it possible you have a clogged oil passage from when you had the motor apart, and the top end is running a little dry at RPM?
alright so 1st post
-I am supercharging my engine, the stock can only handle 250, these are stock compression just better material
-no valve train work done
-sounds pretty fast, but I can get it to not make the noise
-semi loud, when the windows are down I can notice it, in the car not too bad
-It feels a sluggish. I know there is a leak somewhere, just by the hissing noise it makes
2nd post
I’ll definitely check those sensors, I did replace my spark plugs as soon as I saw the code, so those are fine
3rd post
It may be clogged, I too thought something could be a little dry, but I did just take the valve cover off and grease up all the moving parts and it still makes the noise