Today I took the car to a highly recommended BMW Indie near me for a diagnostic check and it came back with no errors (apart from a few bulb out type codes). So the good news is no faults were found but the bad news is there were no faults found. The technician checked turbo and vacuum pipes and all was ok but he said that he was able to see the inlet manifold had a carbon build up. He was able to see this from peering into the inlet but now they want the car back to remove the manifold to check how bad it is. The problem I have is that this seems to be an open cheque book way of diagnosing and fixing the problem which could end up costly.
The inference here is that there is a carbon build up/blockage that is preventing the engine breathing properly causing it to bog down under heavy load and chuck plumes of black smoke out the rear.
Before I hand it over to a specialist to figure it out and rape me and my minuscule bank balance are there any things I can do myself? I am not willing to take the inlet manifold off having seen the procedure explained on here but what about some sort of foam cleaner? Also is it feasible to remove the dreaded EGR valve or will it fail an MoT if I do?
Any advice would be greatly received as this really needs to be sorted out now as it has taken the shine off of my X5 ownership experience and I know there is a great motor there somewhere.
