I just got my HHR almost two weeks ago. I noticed on line that you can buy a replacement oil filter cap. I can understand changint the rubber gasket but the cap doesn't look like an item that needs replacement to me. Is this an item that requires regular replacement? If so, how often should it be changed?

 

Not an item that needs regular replacement. Should last the life of the engine.
But,since it is a plastic(or composite?) it is possible to strip the threads, round off the "nut" on top or maybe even crack the cap itself. That's why replacements are available.
As long as you take care and use the correct socket, there shouldn't be any problems. Just don't overtorque it when reinstalling.
Now if Bubba at the quick lube joint does your oil changes, all bets are off!!

 

Some people replace the cap on every oil change others don't. I have not replaced mine. I think some people like the pice of mind of replacing it with a new one because its made of plastic and if it fails its the cost or a new engine.

 

We don't have any Bubba's up north , only Billy Bob,Joe Bob,Charlie Bob,
Bobby Bob,Sue Bob and Fred!

 

If it's overtightened it can crack. I'm still running the original cap and gasket from 06...... No issues.

 

Oddly, I noticed somewhere a while back that GM was selling the filter and cap for a dollar or 2 more than a filter only.

 

I replace the O-ring every oil and filter change, but the cap is still the original

 

You can purchase the AC Delco with the cap in the parts stores for just a buck or two more than just the filter.

 

Maybe in your area but not my local parts stores. I've checked all the local parts stores here. They all have the filters, just don't have the filter/cap combo in stock. They did say it could be ordered.

 

It might be a good item to have around. I can see cracking one at oil change time and being unable to find a replacement.