Recently purchased a short-block (S4 NA) locally. It was supposed to have 80k original km (50K mi), and the previous owner removed it to do a swap. I have no reason to doubt the previous owner's honesty, but I was specifically trying to avoid buying a rebuilt engine because I would rather either rebuild it myself or use an unopened factory engine.

Anyways, now that I'm cleaning it up I'm noticing some signs that it may have been rebuilt. First off it had an Exedy stock replacement clutch, so someone managed to break a clutch in less than 80k. Second, it had these markings under all the grease on the side of the engine:




Someone marked the front and rear housings. It's some sort of enamel and the de-greaser I was using didn't even touch it.

Anyways, either way the plan is to try running it and see what happens. I was just curious if someone knows if these could possibly be factory markings, or if this engine has been opened.

Thanks, Chris

 

a clutch in 80k, isn't unreasonable, its early, but its within the realm of ok.

those markings are not factory. they look like junkyard markings? i mark the front and rear rotor housings (if needed), but its hard to mix up the irons, so maybe its there to keep someone from pulling the junkyard engine apart and retuning junk?

just some signs of a factory engine.
1. the pulleys, oil pan, and water pump are painted, but everything else is bare aluminum, or nirtided cast iron (gray color).
1a. the fasteners on the engine should have no paint on them either, they are either gold zinc, or a dark zinc
2. Mazda uses a gray silicon to seal the oil pan, no gasket, gasket is for *******. black, red, orange, are all right out
3. there is a stamp on the front iron with a sequence number, Exxxxxx, and then the rotor housings will have a F or R stamped on top. Front and Rear, obviously they should be in the right places.
3a, the housings have casting letters, and these should be correct. i'm not 100% sure, but i think all three irons should be E
4. the tension bolts have no marking on them, common for these to get marked with the sequence or something.

 

Possibly. The previous owner was sure this engine was original, but he wasn't the original owner of the car so it's possible it had been replaced in the past.

Check and check. Everything looks stock.

There is gray silicone on the pan

Check

All three irons are E

This one is a bit weird, they have something like red marker or a red coating. BUT they aren't numbered, it looks sort of like a red coating that has been slowly wearing away? I have two other sets of tension bolts, no red at all on those.




Weird. Not really sure what to think about this one.

 

well you have a factory set of housings, so you're in good shape. the pics sort of point to it coming out of a wrecked car, and then going into another one, but who knows?