| Whomever told you that is nuts. Plugs are just are easy to do except the #12 on the driver side, it is tight, but I have done it twice already. Intake manifold gaskets are a DIY job and it's not difficult at all to do, just wastes time. While doing the job, there are other maintenance items to get as well since the engine is open, mostly preventative. The 850's have the intake manifold deal and the 840 have the Nikasil block problem, same as some 5 and 7 series. Otherwize, they are reliable. I have 118K miles on. |