Here is a guide on things to consider BEFORE buying you second hand engine whether its from a wrecker or a guy who crashed his car. There are soo many hidden problems in an engine that you and maybe even the seller DO NOT KNOW; probably about 60% of a cars parts are engine parts shows just how complicated engines can really be!, especially if there a turbo engine not as complicated for a supercharged motor. Performing an engine swap or whatever can greatly increase a cars performance OR it can also cause enough nightmares to start pulling hairs out.. Heres how to avoid buying a LEMON motor.
Obviously an extremely dirty and oily motor is a sign that it has had a long life with probably little maintenance. Not good. However, also be wary of engines that are squeaky clean; it could have been recently cleaned to disguise its age. Look out for typical serial number stickers or print markings that are on gearboxes. If these are missing then chances are the engine and gearbox have merely been scrubbed clean.
Take off the oil cap and peer into the rocker cover with a torch. This is your only real chance to look inside the engine that you are buying so this is very IMPORTANT. Check the valve train for any sludge build-up on the components, as this can indicate that the engine has missed a service, or three. Take note of the colour of the oil as well, any hints of white or light yellow are caused by coolant mixing with the oil. uh oh Stay extremely clear of this as if you really want to keep this engine (after you buy it) then you will need anything ranging from a new head all the way to a whole new block! BAD.
even if the salesmen says the engine had only don’t 20,000 km play it safe and swap the timing belt for a new one before installing it in your car or whatever you plan to do with it. Salesmen like to be a bit creative with the truth so its better to be safe than sorry. about 80% of people wont and DONT no how to set an engines timing if the belt breaks.
SCRATCHES AND OTHER COSMETIC PROBLEMS:
Don’t worry to much about small scratches and stuff on the rocker cover. These are quite common with written off cars or at wreckers. As the rocker covers paint was probably worn away by the hoist chains when it was pulled out of the donor.
Yes, there is more than one way to test an engine. If the owner says he can show you it running somehow then yes, ask to. Other than that you should probably do a leak down test and a compression test. A compression test is done by feeding a compression gauge into the spark plug hole and cranking the engine. A leak down test is a measurement of how much air pressure escapes (leaks) from the valves. This is not totally necessary but is more needed the more valves there are.
Look out for any oil that has emerged form between the head and the block. Oil attracts dirt and dust, so it will be immediately apparent. This may indicate a damaged head gasket. However a bit of oil weep from beneath the rocker cover is quite common and can be remedied by resealing the cover.
Are the engine mounts intact? if your planning a custom engine swap then youl almost definitely need these for the conversion. Examine the rummer mounts to see if there broken. If a mount is damaged then chances are the donor car was probably involved in a front end accident. FIND A DIFFERENT ENGINE because who what else will be wrong with this sucker.
Check around the water pump and thermostat for signs of leaking coolant. A powdery white/yellow residue is the huge giveaway.
In most cases you need the entire wiring harness, including the ECU, to perform a hybrid engine swap. Even if its heaving discounted, try to avoid engines that have had there harnesses cut. There are an absolute nightmare to rewire and finding a replacement harness can be extremely difficult.
WHAT ARE YOU MISSING??:
Some wreckers are dodgy, that’s a fact of life. inspect the engine carefully and make sure everything is there. Often wreckers or even just ordinary neighbourhood people will remove parts like injectors or water pumps, and sell them off separately if there’s a demand for them.
TO SUM THIS ALL UP HERE IS AN EXAMPLE:
my good m8 jonno bought a Nissan sr20 turbo out of a wrecked 200sx . He did not no what to search for as he was only starting to modify cars. Anyway He had to spend almost $3000 on parts such as the broken water pump and his horrifically damaged exhaust manifold - luckily for him he was replacing this for a high performance one anyway. and last but definitely least it has offset timing (i expressed how complicated this is above)
Here isn’t the engine he bought, but this is the sr20det turbo (not the sr20de version)
just notice how complicated everything is!!
Hope you enjoyed this guide and received a lot of help :)