I’m here, congratulations on #10, try cleaning the throttle body and the MAF sensor .
It could be the time sitting until you bought the HHR

Thanks Blue.
Will keep that in mind as I slowly work on the bucket list. Gonna first do the 3 bottles of Techron and see what effect if any.
If when I try the lower speed matched RPM test it indicates it could be the Clutch Convertor, then I will have to see where I go from there.
The fact that it has a different surge from 25 leaves me in question.
One surge is from a gradual increase in throttle position with no response while the other surge is from a steady throttle position with a surge up.

My last 2010 HHR 2.4L auto was without either of these issues. Very predictable under all throttle positions.

Still curious on the earlier Mobil 1 Dexos question if anybody has an opinion....

On another note, this is my first White Vehicle since way back in the early 60's I bought a White 1959 Chevy Impala 2 Dr. Hardtop with the red interior.
That was a nice riding car.
This 2011 HHR White is really "White" and I am slowly adjusting to it. The Ebony interior helps some.

Silverfox

Honestly, as far as our economy class HHR's go, anything rated as FULLY synthetic 5W-30 is sufficient as far as oil goes.... Hell even good ol conventional is fine so long as you are good with changing it.

You explain symptoms of a dirty throttle body and or a stuffed up air filter.

Yes.... New AC Delco Air filter has arrived and I will be putting it in starting in 20 minutes.

From the looks of the cabin filter it might need changing now anyway.

It will take the Techron a few tanks full to get any results if it in fact does help.

I follow that practice on every used vehicle I have purchased. Some it has made a noticeable difference if you are sensitive to slight changes.

Fresh 92 octane should be a plus as well. It had a half tank when I got it. Not sure how old the fuel was.

I have had a Very positive response from friends and strangers already on the condition and appearance. The ebony interior does help set it off....

I put the rear bumper protector on this A.M. and that helps the appearance even more.

It has factory running boards so I doubt I will need to add mud guards.

No paint chips anywhere on the vehicle. Hood and Rear fenders are perfect.

Just checked the rear inside compartment and found a new AC/Delco OE replacement battery so that bucket list issue is resolved. They furnished me info that states it got a new battery but I thought it might be a non brand or cheapy but that's not the case.

Spare tire had 12lbs. of air..... I'm sure never checked since new. Very common ... Every one I have purchased, the spare was very low on air. Tire has never been on the ground.

OK .. enough talk ... Now to the infamous air cleaner replacement.

Silverfox.

The Techron won’t clean the throttle body or MAF sensor.

Congrats on number #10 ~!!

Lets see some pics. . . . . !

Blue .... What do you suggest and I will try it in between Techron fills.

Air Filter went as expected. Said a few Nasty words to get it done but everything looked good when finished.
Filter needed to be changed but not excessively dirty from the outside.

Lubed the 3 grommets with a little White Lithium grease.
Really tough getting the single grommet to let loose comming off.
Went back together easily.

First nice day I plan to Clean and Paint the rear portion of the muffler with VHT Very High Temp Flame Proof Flat Black.
You do have to follow the use instructions, but it really lasts and looks good when properly applied.
It's a Header Silica - Ceramic coating 1300-2000 degrees.

Finishes off the 2LT 2.4L Custom Stainless Steel exhaust tip look.

Looking from the rear, The ugly muffler just disappears.

Silverfox

Here's OB's TB cleaning procedure https://www.chevyhhr.net/forums/ss-s...27/#post787693

Thanks RJ I wondered were that went!