CPMB 2.0T- No compression after replacing all 8 exhaust valves

[Robv27]

Hi everyone! Hoping to get some help here!

2016 Audi Q5. 2.0T CPMB engine code.

Long story short!
Friends car... so he was driving and started losing power and finally quit!
He towed the car to his house and called me! Neighther of us are Audi Gurus, but we are mechanically inclined! (I have successfully replaced bent valves on a 2.0T CBFA before)
Missfires on cyl 1,2 and 3. We started doing a compression test in the engine, and cyl 1 and 2, 0 compression... so at this point, we are like... got to pull the head out! We thought it was timing! We pulled the head out and to our surprise it was not timing (could tell chain was a little stretch) So we immediately saw the problem... cylinders 1, 2 and 3 had holes on the exhaust valves ( each cyl has 2 exhaust valves right? But out of the 2 valves in each cyl, only one was burned out. So, one hole on one exhaust valve per each cyl, (1,2 and 3)) cyl 4 had quite a bit carbon built up.
Checked pistons... everything looked great! Obviously no contact from any valves on pistons!

So he ordered and we replaced ALL 8 exhaust valves. Did not replace any rockers, nor springs with new stuff. (Did not see anything unusual other than the 3 burned valves)
Put head back on! (Yes, we made sure not to missplace the exhaust and intake rockers cause they are different)

* We replaced all these parts with new parts:
-8 exhaust valves(lapped them)
-head gasket, Head bolts, intake/exhaust gaskets
-Timing chain, balance chain, all related guides
Timing chain tensioners (both)

We timed everything and re checked 3 times!
Rotated the engine by hand at least 8 times to make sure nothing hit anything! Everything rotated smoothly with no odd noised or tensions (spark plugs were off)
Rechecked timing and it was perfect!
Bolted it all back together!
Cranked the engine by key without spark plugs to make sure it gets oil press on everything before we start the engine.
At this point, we install 4 new NGK iridium spark plugs and all 4 coils!
Engine wont start! Sounded like no compression again! Did compression test on all 4 cylinders! 0 COMPRESSION ON ALL 4 CYLINDERS 😪!!!
Could not believe it! Pulled all 4 coils and plugs back out, checked pistons for any contact with valves... Pistons did not have ANY contact with ANY valves!!!
? Could this have anything to do wit any valves staying open? Maybe because of the exhaust cam with the VVT stuff on it?
? Could it be because we did not raplace the rockers?

Any ideas or input will be greatly appreciated!
We are not touching it again until Monday!
We are both actualy taking Monday off to try to figure this out!
We are really frustrated and puzzled by this! Please help!
Thanks in advance!

[Smac770]

CPM, it's VVL on the exhaust cam, not VVT. VVT is on the intake cam.

CPM exhaust valves are not the same as CAE exhaust valves. The CPM also has different exhaust valve seats in the head. All this is due to the higher forces of E85. Buddy is tuned or running a lot of E85? I can't imagine a normal use scenario would create such an issue. But maybe it's just the hot spotting from carbon build up.

Got nothing for you on the physical side, not a thing I've done before. But you're likely to get more view to people who have messed with this by posting in the B8 A4 forum or B8 Q5 forum. Engine internals is the same between the two vehicles, so it's just a matter of where are the people that can help watching.

It could be the timing did not set correctly when putting it back together? Not unheard of to have problems with the sprockets on the cams rotating (they are only "press fit"). But it sounds like this is not a timing / collision situation. So has to simply be something with those valves sealing?