How would I test an engine at a PICK AND PULL yard...

You can’t. They don’t have normal starters.

Either cross your fingers or buy from a reputable company


-Spiral

 

Most places that sell used engines will guarantee them for at least a little while (DOA warranty.)
If the the place is too sketch to back up what they sell, then you're going to have to satisfy yourself with a physical exam, and truth be told you can probably determine rather quickly what kind of life the donor car led by running the VIN through all of the usual tools.
You might get lucky and find...say, a 2015 with 30,000 miles and a verifiable service history that was totaled in a rear-end crash but that type of engine is going to probably get snapped up by a repair shop for top $$.

Since you're in the California, I'm guessing that there are quite a few donor vehicles available locally, but in the end, how finicky do heart-lung transplant recipients have a right to BE?

 

+ you could turn the engine via the crankshaft manually, to see if it has seized. Asides that, no way you'd know unless it is in the car.

 

Be aware that miles written on the engine could be marked down to make you “believe” those are “actual” miles driven.

 

at least with a guarantee, you only have to remove it and replace it again, easy peasy

 

I'd bring an oil filter cap wrench and pull the oil filter to see if there is any debris caught from the oil sump. I'd also go over the filter with a magnet to see if there is any metal there.

Basically, you get what you pay for. You want cheap; you probably get an engine with many miles.

A fully rebuilt engine might be the best way to go.

 

Buy an engine from a wrecked car, not a flood car. Make sure it was a rear hit, not a front hit. Don’t ask me how I know...

If it is a low mileage engine (<75k or less), reseal the timing cover, replace the water pump and replace the thermostat before installing.

If it is a higher mileage engine, replace the head gasket before installing.


iPhone ? Pro

 

I have always preferred rebuilt engines. O rebuilt all the engines of my clients. They last much longer, and you're even sure of the internals.

 

I agree with you that they are worth the extra money.

 

Take all the spark plugs out and run compression on all 4 cylinders by turning the crank shaft with a large ratchet. If your average difference is within spec, that's good #1. Next drain the oil and examine it and the filter. If you see a bunch of metal shavings or chocolate milk it's a no go. Lastly you can put a camera in the cylinder and see its condition.

 

You can do that? A slow crank will work, build up pressure fast enough? Interesting. (Not trying to be sarcastic, just never thought of doing that.)

 

"A slow crank will work, build up pressure fast enough?"

Dubious, at best. Dubious, unless of course you are the Hulk...

 

Hotwire the starter with a car battery haha

 

at about 250 rpm, which is kind of the standard 'starter' speed expected for compression tests, and I think also the speed you get if you use Techstream to tell a Prius "crank the engine for compression test please".

If you have a spare four-cylinder engine around the house to practice on, you can build up your 250 rpm ratcheting technique until you are in shape to go out to the pick-n-pull yard and do it for real. Maybe also make some money getting the pick-n-pull staff to bet you can't do it.

Hmm, maybe a starter rope from a lawnmower, wrapped around the crank pulley....

If you take a leakdown tester with you, there's a test that will give you the same info and you can do it on an uninstalled engine. You do need to turn the crankshaft 3 or 4 times to position the valves for each cylinder's test, but you don't have to crank it fast. And you need an air compressor, or a tank of air you can fill up first.

Prius engines are easy to turn. You can spin the crank to each cylinder compression TDC by hand. But you will want a longish wrench to hold the crank in that position when you apply the air.

 

That sounds like a plan.

Unfortunately though, I have an overactive imagination, keep picturing this guy:

 

That sounds like all of us.

 

Long process. If it were an Otto engine with a starter, then YES, to find out if engine has seized.

 

A Prius engine normally turns easily by just your hand on the crank pulley. Makes finding out if it's seized pretty straightforward.