KYWalker

Looking for a little advice/pointers. Started getting a tapping noise on a fresh rebuild. Road tested a few 15 minute sessions, then all of a sudden....tapping.

Doesn't sound or appear to be in the bottom end. Pulled the motor, pulled the pan, all bearings look like ok.

Pulled the cams and the only thing that looks odd to me is the attached picture...y'all think that might cause a lifter-type tapping noise? The cam cap has similar scratching marks.




In case I haven't set my sig, this is a 2004 MazdaSpeed motor...recently built:
Manly rods, supertech forged pistons, and a bunch of other goodies. Head is all stock except for a valve job.

fredb

iTrader: (1)

Don't know about the lifters but the cam bearing looks kinda scarey to me. FredB

ryansmoneypit

iTrader: (6)

Yeah, something has definitely run through the oil. I am betting the head gasket was upside down and starved the cam of oil.

KYWalker

Pretty sure it isn't upside down, but it was originally lacking oil... Chewed a bearing... Requiring said rebuild.

ryansmoneypit

iTrader: (6)

Pretty sure, or positive? They usually last less than 30 minutes if it is. If it was good, then on the rebuild you didn't clean the gallies? Like we said, the cam bearing are looks like doo doo. I can see aluminum in the oil port.

KYWalker

Since we haven't pulled the head back off yet, can't be completely sure.

Do you think that would cause the Tapping? That's the only thing we've seen that didn't look good.

ryansmoneypit

iTrader: (6)

Could be. Could also be another bearing. Have you had the entire bottom end apart? Rods and mains? What did the oil look like, all sparkling?

an engine that starts quiet and begins to make noise, is not healthy.

KYWalker

Rod bearings all looked good, but we haven't looked at the mains yet. Oil looked normal...not like it did when it ate the bearing.

DanBrown

iTrader: (1)

Was the head 'tanked' when the valve job was done?

KYWalker

Good question... I don't remember, but I'm guessing not based on what looks like crud in that passage.

DanBrown

iTrader: (1)

If you can get the crud out of those passages, check and see if it's aluminum from the head or a bit of bearing. (If there is enough material)

ryansmoneypit

iTrader: (6)

It's aluminum.

DanBrown

iTrader: (1)

Hmmm, well I'm out of ideas.

Might be a no brainer but.... did they torque the camshaft down correctly?
Other than that I feel like it has to be oil starvation like mentioned above.