is there a way to truly tell if an engine is rebuilt? when i bought my 10ae, the original seller had told me that he got it rebuilt at 90k, the car now has about 150k. he didnt show me any paperwork when i asked him (red flag) but as a leap of faith i believed him and purchased the 10ae. so my question....can you tell if it has recently been rebuilt or no? oh and plus how do you go about finding a vacuum leak. cuz i have one and it sucks.

 

Cleanliness maybe, but not a sure-fire way. Maybe a compression test? Pull the transmission and see if the tension bolts are marked for torquing. There really isn't any reliable way of telling, other than it should have decent compression for a 60k engine.

Vacuum leaks are easy to find. Shoot some brake cleaner around intake areas. If the idle smooths out, you've hit it.

 

The only way to know for sure is to tear the engine down..... other than that you can run a compression test. Anything over 90-95 PSI is considered acceptable. As for the vac leak, grab a can of carb cleaner and start hosing down vacuum lines and until you here the idle go up.... there's your leak.

 

^ Yea tear down the engine and find out lmao

 

I think all factory engine have a serial number on the housing. if you just rebuild using a new housing, there will be no serial number.

At least I know my Rx-8 engine have serial number on it.

 

Check for signs of Rtv in places such as the UIM/LIM .oil pan,front cover,water pump.

 

from what I remember on my old NA, my mazda reman that I bought had a remanufactured sticker and also had "RE" stamped on the rotor housings.

Like your avatar by the way, do you have a full size version I could see?

 

most rebuilders paint their engines, which isn't usually too difficult to tell if the engine has been painted or not. aside from that the next easiest way to tell is when pulling the engine apart and seeing the type of parts used and if their condition macthes the expected mileage of the engine.

 

Compression test would be simply the easiest way. If money is a factor and you have somewhat low compression and the vehicle still runs, you can keep driving it until you can afford a rebuild.

 

just drive it till u have enough for a rebuild. thats my plan.

 

With 60k on the rebuild its going to be hard to tell if it has been rebuilt or not, unless as Karack mentions, the housings are painted. RTV is NOT a good indicator since just the manifolds or oil pan may have been removed for one reason or the other.
Even on teardown I would venture to guess most people could not tell if the engine has been rebuilt or not, as many use OEM Mazda parts in their rebuilds.

 

many people no, but it's not too difficult to tell from the trained eye. the stock OEM oil seals get very brittle after about 10 years regardless of mileage.

 

True enough! Someone who knows what to look for, and what that looks like, will be able to tell if its been rebuilt on teardown.