Inspecting a Used Motor?

[JayB12]

I want to go look for a good 6bolt for a spare motor/something to build. What is the process for inspecting a used motor? I don't want to end up buying something with deep gouges in the crank or is damaged more than I would suspect. The one I'm currently looking at is assembled and timed. Also how do you move these around without damaging them?

I'm thinking just pull the pan and check each rod for movement then tug on the crank and look for play. Rotate the motor with the crank sproket and check for binding. Anything else?

 

[jimbob_843]

You"ll always be taking a chance on a motor until you do these things. Drop the pan and every rod cap and crank cap (6 bolt). Check the bearings for wear. While ## in there check out the cylinder walls. Secondly, compression test, this will tell u a ballpark estimate on the rings head gasket and valves. Thats about it but remember if u pull the caps to propperly torque them back. Oh and dont forget that pesky balance shaft.

And bring a feeler gauge to check crankshaft endplay at the trust bearing. Even doing these things are still taking a chance because you wont know if the engine was propperly built. As in bore, clearances, ring gaps. But if these steps check out and the motor has miles on it you can only assume it will do good.

 

[JayB12]

Isn't there any way to get a decent read on it short of all that disassembly?

 

[92AWDHX40]

Gonna have to tear down to see.

 

[TSIturbo91]

You"ll always be taking a chance on a motor until you do these things. Drop the pan and every rod cap and crank cap (6 bolt). Check the bearings for wear. While ## in there check out the cylinder walls. Secondly, compression test, this will tell u a ballpark estimate on the rings head gasket and valves. Thats about it but remember if u pull the caps to propperly torque them back. Oh and dont forget that pesky balance shaft.

And bring a feeler gauge to check crankshaft endplay at the trust bearing. Even doing these things are still taking a chance because you wont know if the engine was propperly built. As in bore, clearances, ring gaps. But if these steps check out and the motor has miles on it you can only assume it will do good.

That's pretty sound advice. I'd add to that to check all the sellers feedback if you can. Plus an inspection scope can be useful. I always check the oil for abnormal color an smell too.

The only way to get a "read" on it is what's been mentioned really. Short of tearing it all apart for visual inspection.

Now I just got a long block assembly myself and know its a combination of luck, faith, inspection and research. Your first step was to post this thread. Next is to deal with a stand up guy. Even if he did everything right and you deal with honest Abe a part could be defective and blow in 100 or 10,000 miles

 

[NEpilot]

There is no good way to be 100% sure....

In addition to what has been mentioned a good compression and leakdown test will generally give a good snap-shot of the engine. The problem is you really can't know exactly what has been done or the quality of the work until you completely tear it down (important things like surface finishes matter). If your the type to put 1000-bucks on RED in Vegas go for it but IMHO it is far smarter to just buy an engine in reasonable shape and start from scratch.

 

[kraig milton]

Buying a used engine in always a risk. I have a hard time shelling out the money for one, especially when the mileage is unknown. To me its always been a toss up to rebuild or just buy a used motor, I cant make up my decision! good luck!