N52 in big trouble!
 

Hi everyone. Im here agaub after changing the VCG on my x5. I thought it went alright, except I have some sludge in my valvetrain even though the engine ran smooth.

On first start up, it ticked, after driving 5 minutes, it started making lower chattering noises, and another 5 minutes later it was still going on to the point where I could hear it a little bit from the cabin. Does anyone know what went wrong?

Thank you

Édit- I also changed the spark plugs at the same time

Lifter tick? Did you record the noise? Maybe post it up so we can listen.
There are a bunch of youtube videos on how to bleed the lifters if it is that. From memory it involves holding engine at 2500-3000rpm with no load for a prescribed amount of time (3-5 mins springs to mind)


2012 E70 50i

I'm worried to even start it now. Is it called 'tick' because it makes a ticking sound? It was like that at first but it became more of an irregular rumble/chatter from the top end.

Thanks for your reply!

You drop a tool in there? Use a torque wrench to tighten everything? Maybe a bolt came loose? Any codes? Did you inspect the chain guides that were visible? I also seem to remember certain n52's having problems with the cam gear bolts sheering or backing out.

I doubt the sludging is the problem. Here is what a 182,000 mile n52 looked like last year when I bought my E61 wagon. Previous owners were not kind. Looks much better now after some Seafoam and ATF in the crank case treatments. Runs like a champ.

https://i.postimg.cc/FzhKXkph/20190705-230031.jpg

Thank you for your reply. I certain dont think I dropped a tool in there, especially since I didnt hear anything or use many tools while it was open. I did torque everything to 8.6nm. I didnt look around the chain in detail but at a glance it was alright and didnt cause any problems before. The cam gear bolts were alright and flush with the surface of the gear. My sludge was maybe a bit worse than yours but didnt cause problems before so I doubt thats it.

I forgot to mention that I changed the plugs too, ill have to check that they're properly torqued. The last thing I can think of is the furthermost spark plug gasket falling off into the valve train. Is there any way the noise could be from oil deprivation because thats what worries me the most.