Engine inspection

Jump to: navigation, search
(Some points to check:: Add text, links)
(Add links)
Line 4: Line 4:
 
==Let the buyer beware==
 
==Let the buyer beware==
 
In almost every case of the casual sale of a used engine, the sale is considered to be on an "as-is" basis. So regardless of what might have been said or inferred about the engine condition or specs or what parts an engine may contain, it is the new owner's responsibility to check the entire engine over to be sure it's what it's supposed to be, or if it needs additional work or parts in order to be usable.
 
In almost every case of the casual sale of a used engine, the sale is considered to be on an "as-is" basis. So regardless of what might have been said or inferred about the engine condition or specs or what parts an engine may contain, it is the new owner's responsibility to check the entire engine over to be sure it's what it's supposed to be, or if it needs additional work or parts in order to be usable.
 
==Checking engine's basic health==
 
First thing is to look at is all the fluids and the air filter to get an indication of how the engine was maintained.
 
Check the oil for water and the water for oil. Either can indicate a blown head gasket or cracked block.
 
 
Remove the breather and PCV to look for obvious signs of sludge. Check cooling system for rust and the radiator for clogged tubes or evidence of leaks that could have caused overheating.
 
 
Next, start the engine and warm it up. Remove one spark plug wire at a time using an insulated spark plug boot puller, noting any change in idle speed. If the idle speed drops, that cylinder was firing. Go through all the plugs and if there was a plug or plugs that the idle speed remained unchanged or nearly so, the next step is to see if it's a problem with the plug or wire. Remove the plug wire from the weak cylinder and swap it with a plug and wire from a cylinder that was working normally. If the weak cylinder is now OK, it was either the plug wire or the plug. Swap the wire from the weak cylinder with another good wire and see the results. If the miss followed the wire, the wire is bad, If not it's the plug.
 
 
If the miss did not follow the plug or wire, that cylinder or cylinders need to have a compression test performed on them. With the throttle propped wide open and the ignition disabled, crank the engine over letting the cylinder come up on compression three times. Note the reading. Next, squirt oil into the cylinder through the plug opening and test again. If the reading doesn't change, likely the valves aren't sealing. If the pressure comes up, there's a good chance it has worn or possibly broken rings.
 
  
 
==Engine ID==
 
==Engine ID==
 +
 
===Casting numbers===
 
===Casting numbers===
 
Using the casting numbers, casting dates, and suffix codes will all help identify the basic specs of an engine, regardless of the make. So if an engine needs to be verified as to displacement or other parameters, start with the casting numbers and any other visual cues that might be present.
 
Using the casting numbers, casting dates, and suffix codes will all help identify the basic specs of an engine, regardless of the make. So if an engine needs to be verified as to displacement or other parameters, start with the casting numbers and any other visual cues that might be present.
Line 32: Line 23:
 
If this doesn't work for you, pull a head and/or the pan. I would strongly recommend doing this anyway in order to verify exactly what it is you have and to check a few things while you are there:
 
If this doesn't work for you, pull a head and/or the pan. I would strongly recommend doing this anyway in order to verify exactly what it is you have and to check a few things while you are there:
  
==Some points to check:==
+
==Checking engine's basic health==
 +
First thing is to look at is all the fluids and the air filter to get an indication of how the engine was maintained.
 +
Check the oil for water and the water for oil. Either can indicate a blown head gasket or cracked block.
 +
 
 +
Remove the breather and PCV to look for obvious signs of sludge. Check cooling system for rust and the radiator for clogged tubes or evidence of leaks that could have caused overheating.
 +
 
 +
Next, start the engine and warm it up. Remove one spark plug wire at a time using an insulated spark plug boot puller, noting any change in idle speed. If the idle speed drops, that cylinder was firing. Go through all the plugs and if there was a plug or plugs that the idle speed remained unchanged or nearly so, the next step is to see if it's a problem with the plug or wire. Remove the plug wire from the weak cylinder and swap it with a plug and wire from a cylinder that was working normally. If the weak cylinder is now OK, it was either the plug wire or the plug. Swap the wire from the weak cylinder with another good wire and see the results. If the miss followed the wire, the wire is bad, If not it's the plug.
 +
 
 +
If the miss did not follow the plug or wire, that cylinder or cylinders need to have a compression test performed on them. With the throttle propped wide open and the ignition disabled, crank the engine over letting the cylinder come up on compression three times. Note the reading. Next, squirt oil into the cylinder through the plug opening and test again. If the reading doesn't change, likely the valves aren't sealing. If the pressure comes up, there's a good chance it has worn or possibly broken rings.
 +
 
 +
===Some points to check:===
 
* '''[http://www.crankshaftcoalition.com/wiki/Valve_train_points_to_check HERE]''' is a list of valve train points to check, including the valve train geometry. This doesn't require any disassembly other than the valve cover to be removed and should be checked ''before'' tearing the engine down.
 
* '''[http://www.crankshaftcoalition.com/wiki/Valve_train_points_to_check HERE]''' is a list of valve train points to check, including the valve train geometry. This doesn't require any disassembly other than the valve cover to be removed and should be checked ''before'' tearing the engine down.
 
* Condition of the spark plugs (oil consumption, correct heat range and air/fuel ratio)
 
* Condition of the spark plugs (oil consumption, correct heat range and air/fuel ratio)
Line 51: Line 52:
 
* Wear patterns on the pistons
 
* Wear patterns on the pistons
  
 +
==Resources==
 +
;Crankshaft Coalition articles
 +
*[[Troubleshooting- a sound diagnostic approach]]
 +
*[[Ford engine specifications]]
 +
*[[How to rebuild an engine]]
 +
*[[How to prep and start a rebuilt engine]]
 +
*[[Identifying AMC/Rambler Gen-1 V-8s and transmissions]]
 +
*[[Identifying Chevy engines]]
 +
*[[Pontiac V8 engine]]
 +
*[[Rebuilding an early Hemi engine]]
 +
*[[Rebuilding an Oldsmobile engine]]
  
 
{{youcanedit}}  
 
{{youcanedit}}  
 
[[Category:Engine]]
 
[[Category:Engine]]

Revision as of 20:26, 25 June 2012

Personal tools
Namespaces
Variants
Actions
Navigation
Categories
Toolbox