Hi guys,

My car has done around 168,000km (~105,000 miles), it's a 2007 E60 LCI 530i 3.0L N52 engine. I've done some extensive research on carbon buildup in the cylinder/valves but most of the information is based on the direct injected models which seem to be a lot more problematic, however not much information I could find on the port-injected N52s.

I'm not suffering from any major engine problems at the moment, but the dealer has recommended that a lot of gaskets be replaced due to oil leaking, and one of them is the intake manifold gaskets so I have purchased the parts and will be doing that soon.

I don't have an air compressor or any of the tools needed to do a walnut blast and without taking apart the manifold I can't see the condition of the valves. So, does anybody have an N52 or know if we need to do a carbon clean? I do have a can of Seafoam available that I suppose I could use to soak and scrub but if it's that bad I'm considering buying the air compressor and walnut blasting machine prior to opening her up.I just don't want to spend all the money buying all the equipment, then find out it's crystal clean inside!

Thank you!

 

No need. Don't worry about it.

Your valves get cleaned with the fuel

 

Agreed, especially if one uses fuel cleaning additives such as Techron regularly. In my over 1,500,000 kms in 45 years in 8 BMWs, I have never experienced valve carbon buildup. Those were on port injection engines, although the 3 first engines were carburated, Strombergs, I think. The direct injection engines have the problem because the fuel doesn't pass by the intake valves, hence no cleaning action.