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Hey guys, I've got some bad compression in my #2 cylinder and was wondering (maybe in futility) if there's anyone out there that's got a spare head to a BP? Seems like a pretty ridiculous request, I know, but... Might as well see what's out there, y'know?

Failed leakdown test?

Haven't done one yet. It's making a lot of engine noise, and a compression test showed good readings for all cylinders but #2. So, following a friend's advice, I'm looking for a head that I can just swap out.

Might just be a lifter.

Thanks, I'll look into it further. My friend told me it could be a few things, all of which would be guaranteed fixed by replacing the head.

If the car has sat awhile, try running the engine at 2500rpm for 5-10 minutes. I had to do this on the junkyard engine I bought. Mazda doesn't have the best hlas (hydraulic lash adjusters, aka "lifters") on the planet. High miliage makes it even worse.

Probably not the case, since it's a (fun) daily driver and has been driven regularly for a while now. It's actually kinda sad, this problem used to happen just once every so often, but then one time it stuck. The engine noise was getting worse and worse, and eventually I felt a tremendous loss in power, so I took it to a mazda place to have it looked at. They told me compression in #2 was really bad, and they swapped out the spark plug in that cylinder with one they had lying around. Fixed it for quite a while, but I never did anything about the compression.

But what made it start back up was I took it through the car wash (I work there). It went in sounding great, came out sounding just as noisy as before. I of course suspect the undercarriage flush, since nothing else would affect the engine like that... Not to mention I keep it in neutral and kill the engine for car washes, so I know it didn't just start randomly from the engine running at low rpms or something...

I've got a leak-down scheduled for tomorrow... We'll see what happens! (so much for WTB, eh? )

The only thing head related, would be making noise, cause low compression, and come and go, is a lifter. Maybe one went flat on you.