Used engine vs head rebuild?
 

2008 HHR LS with 130K: CEL P0303, 70 psi compression in #3, failed leak-down test.

About $500 for parts and having head machined...

---OR---

Used 2008 engine with about 45K for $750...

Thoughts/comments/questions?

It is NOT recommended to machine the head. New valves etc. is OK, but I understand that there is no tolerance for removing metal. New head is not that expensive IIRC about $500 on eBay.

You do intend to replace the timing chain sprockets and guides, I hope.

Yes, the chain, sprockets, guides and water pump were mentioned by others, and I'll have all that done if I do the rebuild instead of the used engine. Does this mean your vote is for the rebuild?

Based on the labor saving alone, my vote is for the "new" used engine.

If you are doing the work yourself, and you are capable of it you would save some money. Figure about $1200 labor to switch engines.

Depends on capabilities and wallets. Hassles and time probably favors used.

I am pretty much a maintenance level guy, but the mechanic who has been working with me wants his shop painted, and we are both willing to pay for our own supplies and trade the labor of each other's job.

check that replacement motor over very well, you could have the same issues on start up or in a couple of months, but then again maybe it'll run well for a long time, you just have to ask yourself, do you feel lucky, well do you!??

Right. My father-in-law brought up the same point, and the mechanic working with me said the shop that has the motor is reputable, that he and others have long memories for shops who have sold bad engines. I guess it's the same as buying a used vehicle - some things you just never know unless/until you get inside it.

the shop may have a great rep for selling used engines, but they did not use this engine or maintain it, so again comes the question.
Unless you tear it down to inspect it and add the cost of new rings, bearings, gaskets, timing chain and tensioner, oil and water pump.
I buy used engines as a base to a rebuild, not to use as is in my daily ride, to much of a risk, but I'm sure that it could be a great motor, it's your decision

I would look into a new head as Donbrew suggested.. If it is indeed about $500. That's the route I'd aim towards..