Oldblue

X3 AC Delco 41-103 Iridium spark plugs . You risk piston damage from inferior plugs and thread damage to the aluminum cylinder head .
They come per gapped, do not attempt to regap them, the iridium whisker breaks off pretty easily. And the last 100,000 miles.

WendySaree

This is what i used... it says they are pre gapped to .044

https://shop.advanceautoparts.com/p/...338/20650531-P

RJ_RS_SS_350

Get the right plugs...

donbrew

If you messed with the gap on those plugs that is the problem. Even testing the gap can destroy them.

WendySaree

No i didnt mess with the gap thats what they were preset at. But in the owners manual it says they need to be .040 and to use acdelco 41-103 but the specs on those say they are pre gapped .043 i am so confused!

Cat Man HHR

It does get confusing, here is the plug bought ($9.99)
https://shop.advanceautoparts.com/p/...338/20650531-P

Here is the correct Delco plug ($8.99)
https://shop.advanceautoparts.com/p/...103/15650269-P

Denso says the pre gap is .044"
AC Delco says the pre gap is .043". Measuring a new one out of the box could help with this.

Gap is .001" difference
I have seen running problems when installing different brand plugs.
Could be the case here.

Wonder if there was a problem before changing plugs and thought plugs would fix it.

Oldblue

I tried those plugs way back , they lasted a week, I learned the hard way. I went back to AC Delco 41-103’s

WendySaree

No pre existing problem. I keep my hhr very well maintenanced due to the fact that i deliver mail in it. I try to make sure its taken care of before issues have the chance to form. Im getting delco plugs now. Thank you all so much.

Oldblue

We get a discount from RockAuto, if you’re ordering online.

WendySaree

Really?! I did not know that. How do go about getting the discount?