buying old low mileage parts

[Lil bastard]

Both parts are pretty critical to proper operation of the engine.

A used part such as this is a risk, and both parts are relatively sensitive to rough or improper handling.

And, you won't know if they'll work until they are installed.

What's your backup plan if they don't work? Locate more used parts or buy new?

If buying more used parts, you're just tossing the dice again.

If buying new, well then you've just paid more than retail and had to do the work twice.

All things to consider.

Cheers!

[Steve Tinker]

I think there is a dividing line between second hand electrical / electronic componants and used mechanical parts.

Many (all) electronic componants that are stored from new in their original packaging are usually still good after several years, but those same parts that have been used and then placed on a warehouse shelf or left "in situ" can degrade at an alarming rate - especially if there is high humidity or cold damp conditions.
I was a maintenance engineer before I retired and would treat used electrical / electronic componants with high suspicion, whereas I would store & install good used mechanical parts (obviously subject to inspection) without a problem.

One of the biggest problems we are seeing in the manufacturing industry is the breakdown of the electronic control componantry purely as a result of aging - even if the control system is working 100% one day, the next you can have a complete failure for no apparent reason.
This is going to be the killer for a lot of cars over (say) 15-20 years old in the near future - especially those that have marginal quality ECU's.

[gschotland]

As a general rule I don't buy used electrical parts and wouldn't take a chance on critical parts such as an MAF or O2 sensor unless I got them for free from a known source, like a friend parting out a car with known history. Patching up a car to sell might be another story...

That said, I did buy a used wiper motor for about 1/3rd the cost of new and it's been.

If you're in for the long haul, and it sounds like you are, buy critical electrical parts new.