This is true, BMW made some changes on N62B48s (4.8) that weren't seen on the N62B44 (4.4) so 4.8 owners don't have to deal with the secondary air problems. With that being said we usually see E65/66 and E60 vehicles for the secondary air problems, much less frequent in E53 & E63/64 vehicles.
That being said we have a lot of customers with N62 vehicles in different vehicles, with a variation of mileages, driven in different ways. The reoccurring theme we see, most commonly when it comes to valve stem seal failure, comes down to quality of oil and change frequency. I know some believe this has little effect on these engines but I will offer these two stories of customers I have seen and dealt with.
Customer with an 04 745i has 190,XXX miles on his vehicle. Never been apart for more resealing the top end of the engine: valve cover gaskets, timing cover gaskets, etc. Also had the coolant transfer pipe and valley pan done. He has religiously changed his oil between 5,000 and 7,000 miles with either Castrol or Mobil 1 full synthetic and an OEM filter. Valvetrain is very clean on the inside, no sludge or grime what so ever and the internals are a nice golden color. Car doesn't smoke a bit on startup.
Customer with an 03 745Li with around 125,XXX when he first brought the vehicle to us. Had the vehicle for about 60,000 miles, couldn't remember when his last oil change was so he wanted an oil change, Bank 2 Valve Cover Gasket because it was raining oil out of it, and a diagnosis of his smoky exhaust. Oil was pitch black, no translucency, and the filter had fallen apart in the canister, literally fell out in pieces, couldn't tell if it was OEM or not. Valve Cover gasket was hard as a rock but I was startled when I saw what was underneath and have attached a picture for your viewing pleasure. The car smoked like a chimney from the exhaust pipes. Can't recall seeing one quite this bad. When we quoted him a price he said he'd probably just sell it and move onto something else.
Point being maintenance on any vehicle is key. With an engine that has the Achilles heels of the N62 it becomes paramount to longevity and performance. These two examples are at opposite ends of the spectrum, and there are some outliers but generally speaking this is the trend we have observed.
12-30-2015, 11:54 AM
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