Yes I did read other post about this issue that’s why I’m showing what has been done with the vehicle.

My HHR is a 2011 2.4L automatic with 160,000 miles. For a few months off and on it has a hard shift into 4th gear. Always smooth from park to reverse,drive. 1-2-3 are smooth shifts. When it goes into 4th it seems like a miss and sometimes it’s harder or struggles then after you drive it over two miles it goes away and problem is done and might be for a day or so. I just changed the fluid yesterday as it was due thinking maybe the issue and didn’t find any pieces of metal in the fluid and after removing the filter the parts I could see of the transmission were spotless. Also pulled off the throttlebody and cleaned it all up from oil blow by. Transmission Fluid was dark but not thick in pan. I put 7quarts in it.

For the last two years I have just been using Walmart brand oil for oil changes as I read there oil is just as good. But last month I just recently changed to QuakerState high mileage synthetic. I will give you a run down of what’s been done to the HHR.
100,000 miles-
Timing chain
new belt
plugs
MAF sensor
o2 sensors
Changed crank sensor and camshaft Only reason I changed them was trying to diagnose the timing chain code same reason I did o2 sensors. Figured they were the issue since chain didn’t make noise all the time. Also replaced both VVT solenoids about 60,000miles ago. Have noticed not much pep in the HHR but when you get into the peddle it wants to rip the tires off. Also just got it inspected and no codes and I even checked it no codes. I also pulled the VVT solenoids when I cleaned the TB and blew air into them to see if any dirt came out and nothing came out. Could my VVT solenoids be acting up since I used Walmart oil before? Figured they would have acted up right away years ago. I have never changed the trans mount but don’t see that causes the hard shift and it would effect all shifts. Also just noticed this am days later that I have some drops of I assume transmission fluid but looked dark like oil. So either old fluid from transmission filter change that splashed somewhere or pan needs torqued or loosened. Torque wrench from HF seemed like it was torquing over 18ftlbs when I used it. All said and done I noticed like a wet seal where the gasket and pan met once tightened up so maybe to tight.

Thanks.

 

What brand VVT solenoids did you install and yes the high mileage oil maybe your issue, is it synthetic? Blowing air into them may have damaged the internal parts of the VVT , but doubtful.

 

Don't use "high Mileage" oil! It has additives that can be harmful to the cat and seals. (Be kind to the animals)
The pan bolts torque is 106 lb INCH. That translates to 8 lb ft..

 

One is Acdelco other off brand I think but have had them since the 60,000 mile mark or more should throw a code too. I blew air with my shop vac so wouldn’t hurt them.

So just keep using plain old 5w-30 no high mileage synthetic ? Well crap they are over torqued then could have swore I saw 18lbs must have misread. They were on pretty snug when I removed them.

Any other thoughts? If it is a transmission issue will it throw a code eventually?

 

The how-to says 89 lbs in. Either way, finger tight.

 

Did you relearn the crankshaft sensor? Need a Tech2 or equivalent.

 

No but that was back in 2018 as don’t put many miles on our HHR. Never had a issue. Just drove it around town and shifted smooth the whole time. Except when I first got into it after sitting for 9hrs.

whatever the issue it should be throwing a code?? Right?

 

The crankshaft only codes for "not learned" "broken".not "incorrect variance stored".

Over torquing the pan distorts the sealing surface. I ruined 1 by going "heavy hand tight" (past finger tight). The 106 lb in comes from the 2009 book. 2006 says 124 lb in. I think there was a new guy writing every year.

 

Well I didn’t go torque crazy on it and couldn’t get the HF torque wrench to click at 18ftlbs where I had it set. Pan isn’t warped as checked it.

 

You need to go back to harbor freight, get one for lbs in. They're cheap.