I recently replaced an exhaust valve. All seemed to go well. After I started it for the first time it idles perfectly, but is loud. Slight tapping under acceleration(might subside eventually, it hasn't been as loud since first started). Best heard in the cabin.

Exhaust leak around flex pipe, possible.
Exhaust leak at cylinder 5 manilfold, definite.
Smoking out of the dipstick.
Oil spitting from turbo oil drain line at the block, worn seal, definite.
Replaced PCV last year, 20k miles.
Slightly dirty intake mani and throttlebody. I didn't clean it too well.
Front intercooler charge pipe, worn and old. Choking intake under acceleration, higher RPM.

Question...Could off cam timing be causing excessive crankcase pressure? I will be adjusting it this weekend to see if it helps...any thoughts?

http://youtu.be/MMbxOSkBoCo

 

No, I don't think so.

 

could be worn rings, a head gasket leak or possibly a turbo seal (ie letting pressurized gasses push into the oil return, or your PCV is clogged - when you did the PCV did you clean out the ports into the block or just do the external plumbing? Considering you have a leaky oil return I'm wondering if that may be related (ie bad turbo seal pressurizing system and pushing out the oil?

Have you done a compression test?

 

I just tracked down the massive exhaust leak at the manifold...Apparently when I put the manifold back on one of gaskets had fallen off the stud...So it was letting essentially all of the cylinder 5 gases out. I found it by feeling massive flow with my hand and snapping a picture...A little wrenching, prying, and resetting fixed that.

When I changed the PCV I probably didn't clean it as well as I should have. I am going to take the intake off and clean it thoroughly this weekend. As well as adjust the timing, replace the worn intercooler hose, replace the oil drain seals, do an oil change, and replace all the brakes...

I took compression numbers earlier this week. They were all a little low, but very consistent. 140 across the board. 220K miles might account for ring wear.

Also, while I was fixing the gasket, I accessed the turbo and noticed the 'ol in/out/in/out shaft play. No play up or down. Turbo could use a swap or rebuild...

other than that, it seems to run pretty well, but I am getting more worried about the loud knocking(tapping?)...

 

Replaced the intercooler pipe. Replaced the turbo drain seal and gasket. Did an oil change. Replaced the brakes. Went for a testdrive. No oil leaks, no coolant leaks. Still has a loud sound upon acceleration. I am thinking an exhaust leak? Thanks for any and all help!

https://youtu.be/WAzOCm4OTVs

Also, I will be adjusting the timing because after the spirited testdrive today my powerband is around 5k. I'd like more usable power in the lower RPM range.

 

If you can get under the car with the engine running, check for air or noise around the flex pipe and pipe interfaces (on my 850T, the OEM exhaust developed a crack on the lip of the middle section facing the flex pipe - even though the rest of the system looked great)

 

I figured it out! There WAS an exhaust leak, but NOT at the flexpipe(which actually was in better shape than i imagined). On a cold engine, i started it and felt around. BEHOLD, another massive exhaust leak at the manifold. Loosened the nuts, peaked inside and ANOTHER gasket was off a stud! Back in place and all tightened up. Purrin like a kitten, oh so nice a quite. Happy my engine is back in action. Now it is time to order a turbo rebuild kit. Thanks for the help!
Cheers

 

Good job!