2009 R55 Clubman S n14- So I just had my head professionally serviced (deck shave .007) after burning a valve, got one new valve, new valve seals, pressure tested, cleaned, and in the meantime I replaced all the rings with factory size Mahle rings, clocked properly, they went in as expected, honed the cylinders, spun the engine with the new rings, all looked and sounded great. Fast forward I have the head back, cams back in, all is reassembled, new OEM head gasket, all torqued to spec, timing tool used, flywheel locked, all torque values and angles done, and I have weird compression and no start. Like 50, 100, 125, 100. This is my 1st time on a job this complex, and I did follow the Bentley Manual, except- When I took the cams out I did not map where the hydraulic lifters or rocker arms went, I only realized later that this is recommended. My thinking about this says this would not cause what I am experiencing, although odd future wear of cam lobes might happen. Are these different exhaust and intake? I have not found a reference that the exhaust and intake lifters or caps are different than one another, but I am now worried that they are. Another thing that I think is possible is that stiff or stuck lifters may be holding valves slightly open (which also may mean I have bent valves after cranking) as they were very stiff and I slightly compressed and cleaned them before reinstall, but some of them were very squishy (moved up and down easy) and some were still very hard and moved little. My leakdown test was also odd at loss rates of 25%, 5%, 5%, 65%. I read today that I wont get proper compression until rings seat which now has my head spinning. I have Fuel, I checked the fuel rail. The engine sounds normal when cranking, it but it wont start. If anyone has suggestions I would greatly appreciate hearing them! My confidence is shaken and my next step is to tear it all down and remove the head and start again, or scrap it, I am not sure what to do. This has been a lot of fun, but not fun at the moment.

Don't worry about the compression or leakdown now-

make sure you have fuel pressure, that the injectors are firing, and that the plugs are sparking.

Once you have that, I suspect it'll catch and run.

Yes, you're supposed to keep all the parts in the same places, but with roller rockers it's not a big deal.

t

Problem solved, car is back together and running great. Oil consumption is zero, engine light is off, no codes. Have not checked compression but engine runs strong.The problem was me, I did not have the fuel injectors plugged in correctly, noticed this upon disassembly. Spent a day with my label maker marking every plug, and carefully checking and rechecking at reassembly. Thanks for the help!

Cylinder compression tests should be done with a warmed-up engine and the fuel injectors disabled. If you did it differently, this may be the reason for the unexpected compression numbers, at least in part.

Good luck.

Edit: Just saw your last post. That's great news!

Yes I agree on the warm engine, but I could not get the engine started to warm it. Then with all the strange compression I panicked and took the head off again to check. After looking at the valve seat I really think it may have been caused by some carbon debris slightly holding the exhaust valve open, just a tiny bit. My takeaway is that I should have thoroughly cleaned the carbon from the exhaust ports, or maybe by shop that did the head work should have done that. In the end it all works and I really cannot believe I did it. My plan is to focus next on when I should walnut blast my intake valves because the carbon is coming back I am sure.