buying a junk yard engine how to check if its good?
 

so when pulling an engine at pick and pull obviously you cant start it.

and i already bought a junk engine that i cant return cuz its been way past 90 days.
it has a rod knock and all kinds of leaks
so im gonna have to buy another long block y7 to replace it or a z6


whats the best gameplan to check as much as i possibly can without tearing it down.

i know for one to rotate the crank with spark plugs in to check for burnt valves there will be much less force if one of the cylinders is leaking compression.


but how ot check if the engine has bad bearings or rod knock

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so to keep track



check for body damage
if no body damage then engine is the problem if rolled over also bad engine
if hit on the front, engine mounts or exhaust manifold bolt holes might be stripped

1 spin the crank to see if its seized up or spins freely. if theres no compression the crank will spin much easier with spark plugs in.
2 pull spark plugs and see what they look like and ook inside spark plg holes
3 pull valve cover off and check for buildup and signs of overheating or low oil
4 pull oil pan and check for signs of overheating( black color rod caps and black color crank around bearings) also metal shavings in oil pan
5 sings of heavy oil or colant leaks around engine bay.
6 ask for recorded mileage from junk yard.
7 try to get a warranty

Re: buying a junk yard engine how to check if its good?
 

In my experiences of the hundreds of junkyard trips I've made.. If the car has enough body damage to total it out, more then likely that motor is good. If the car has no body damage or very minor, more then likely the car was scrapped because of a drivetrain issue.

Re: buying a junk yard engine how to check if its good?
 

good point.
is there a way to check for bad bearings?

Re: buying a junk yard engine how to check if its good?
 

You could check the oil pan for metal flakes. I would just change to new bearings though.

Re: buying a junk yard engine how to check if its good?
 

That's what I always tell people. If the body is decent then the motor or trans likely died. And check their warranty because it's usually not money back but actually just a yard credit.

Best way to check is to turn it over by hand first. A lot of these cars you can start if you bring a battery and with a bit of work and car part swapping bam its complete.

Re: buying a junk yard engine how to check if its good?
 

If the cluster is still in the car check how many miles along with the suggestions above. No point in pulling a motor with 300k IMO.

Re: buying a junk yard engine how to check if its good?
 

Also smell the oil, And pull the valve cover. Check for a burnt smell and for sludge. I would pass if the oil is really dirty or burnt and Obviously milky.

Re: buying a junk yard engine how to check if its good?
 

Take a flashlight with you, remove the oil cap and shine it under the valve cover, if it looks nice and clean chances are really good it's a good engine. If it's full of old burnt on oil and sludge pass. If it's still in the car take the rad cap off and check for rust, sludge or oil in the coolant. There's no easy way to check for a spun bearing without pulling the pan, but honestly if it looks clean under the valve cover 9 times out 10 it's a good engine.

Re: buying a junk yard engine how to check if its good?
 

Also try removing the valve cover and inspecting the valvetrain. It should be a golden bronze color if the engine is low miles and had regular oil changes. If you have a black gunky sludge on anything other than just the bottom of the oil pan then the engine may be more suitable for a rebuild rather than startup. Learning how used oil should smell is a great benefit to inspecting engines as well.

If the engine still has oil I like to drain off the first bit and last bit into a small seperate pan to screen for shavings.

Re: buying a junk yard engine how to check if its good?
 

Incidentally, what is the likelihood that a vehicle with body damage has sustained (non-obvious) injury to the head or block? What should you look for?

Re: buying a junk yard engine how to check if its good?
 

If it rolled I'd pass on the engine, running upside down tends to ruin an engine pretty quick. Other than that check very closely for cracks around mounts. Someone told me years ago they had horrible luck buying junkyard B16A transmissions from smashed up cars, they kept blowing differentials through the side of the case, he finally started blaming it on the extremely abrupt stop with the car still in gear, something to think about.

Re: buying a junk yard engine how to check if its good?
 

do a leak down test.

drain oil, or a bit of it from the pan and check it out. look for metal shavings and if it looks milky.

see if you can put a socket on the crank bolt and rotate it by hand

pull the plugs and take a peak at them

Re: buying a junk yard engine how to check if its good?
 

i have an inspection camera that can fit through oil pan hole.
looking at the rod caps i know when they are black is bad because of running with no oil. is black rod cap always an indication of bad bearing or can bearing be bad without any signs?

Re: buying a junk yard engine how to check if its good?
 

Interesting thread, Ive always been curious at the engine.

Good luck though! Whenever I see a Z6 or a Y8 at the junk yard, theyre gone by the time I blink.

Re: buying a junk yard engine how to check if its good?
 

on ex si hx engines you can take off the vtec solinoid off usually there is some metal in there if its bad..

Re: buying a junk yard engine how to check if its good?
 

im sure everyone figured were talking mostly single cam prelude and ls motors.
chances of finding a b series vtec motor are pretty slim...