Digging up an old post, but I am hearing the same noise from my 2.4/auto. I don't want to take it to the dealer for them just to tell me its 'normal'.

Has anyone figured it out what it is yet? I am sure its either rocker/lifter noise or piston slap.

EDIT: I just went outside and popped the hood while the engine is idling. Well, I can totally hear the ticking with the hood up. I am not an expert with these little cars, but it sounds like rocker/lifter noise to me.

I guess I can always go to the dealer and if they try to tell me its normal, we can go and start up a brand new HHR (2.4/auto) on the lot and see if its making the same noise or not.

 

I hear it with my 2.4 as well, but it's only really noticeable when at a stop light with the transmission in gear. If I pop it into neutral, the noise is a lot less.

Both of my previous Malibus had piston slap (one was so bad I had to get a new motor ) I do not think the noise coming from the 2.4 is piston slap.

 

[quote=MEAN HHR]EDIT: I just went outside and popped the hood while the engine is idling. Well, I can totally hear the ticking with the hood up. I am not an expert with these little cars, but it sounds like rocker/lifter noise to me.
/quote]

Ticking with the hood up at idle; it's most likely just the fuel injectors you are hearing.

 

I have an intermittent rattle/growl that has a somewhat hollow sound to it. It comes from the passenger side of the HHR. It does it with the clutch in and out in gear or neutral. I only hear it at idle,

 

Just under 5000 miles on our HHR (2.4 liter auto), and the ticking is loud at startup, and continues until the engine is warmed up. It's not the exhaust, and it's not the injectors. I'll be bringing it in to the dealer next week... I'll leave it overnight if they don't believe me. This will be issue number 11 in less than 6 months. Well on my way to a lemon.