About a year ago I picked up the "Parts List" 626 (http://www.stanceworks.com/2012/05/the-parts-list-joseph-dales-mazda-626-2/
) from Joseph Dale. I really liked how stock and clean the car was, and the simple effect of lowering it and the great wheel choice Mr. Dale had made gave the quirky little sedan that something special. The engine however, was not in perfect health.
So when I brought the Mazda home she was burning oil, and leaking from the valve cover. The compression was within 10 psi across all four cylinders, no more than 6 between adjacent cylinders. It was between 138-148 in total, factory new calls for 170. This made me think that a small amount of it was attributed to blow by, but the pcv looked original, and mazda engines are known for having poor quality valve stem seals. I put on the new PCV and was getting ready to replace the valve stem seals with a handy on engine valve spring compressor. I figured while the valve cover was off I'd clean it up, polish a thick raised band on it, and wrinkle black the rest.
VC off and cleaned.
Coated in aircraft stripper.
Raised front band polished
Wrinkling nicely (crappy cell phone pic doesn't do it justice)
So then I find myself looking at the valvetrain....
...when I realize that the head bolts also retain the rockers and cam on this engine. Once I realized that the head had to come off to do the bit of top end maintenance I had in mind, I considered the mileage and age of the engine, priced machine work and new pistons, rings, gaskets, head bolts, etc, and realized that it wasn't too bad. So in keeping with the by and large original condition of the vehicle, I decided to go that route. So my wife helped me pull off the hood.
Then we yanked all of the accessories, manifolds, fluids, the little bit of harness there is, unbolted the transmission, starter, and engine mounts.
That's how the engine is sitting now, loads of crud in the coolant passages, sludge in the oil galleries, and it appears that there was a bit of coolant finding its way into the oil. The pistons also have seen better days. The engine leveler is attached to the block with the old head bolts, and I plan on pulling her Friday for final disassembly. The head pieces and starter are all laid out in front of my bike right now.
Here is a less than great picture of the carbon buildup/scaling on the valves, this engine has a LOT of sludge in it as well.