5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
I have a 95 530i which idles slightly on the rough side. We took it to the local BMW specialist and they claimed we should replace the "idle air control valve" to correct the low 500rpm idle to a "proper" 600rpm. Simply turning the A/C on does this and the roughness goes away. Otherwise, the car runs beautifully, like it should, and only runs rough when @ idle, cold or warm. We plan on replacing this part, but wanted to see if this was the type of behavior to look for with this "Nikasil" block issue? Maybe at it's earliest stages? I have yet to check the numbers on the block to verify whether its a Nikasil or Alusil... but wanted to see if this was even something to worry about.
117000 mi, 100% maintained by the service book either @ the dealer or with dealer parts @ BMW specialty shop.
Nikasil and alusil are not the brands of the block.
THe nikasil issue is a big deal with v8 powered cars in that year.
Im not saying which you should do, but if it were my car, i'd try the idle control valve if the dealer says so, since the diagnostic tests for the nikasil issue would most likely be the same cost, if not more.
The Nikasil problem is not just confined to the V8's
I have seen a 6 cyl 2.8 use a litre of oil every 300 miles.
Does your engine use an excessive amount of oil?
Rough idling can be ine of the early symptons, however all is not lost.
Try the idle control valve first, it may well be the problem.
If that doesnt cure it, ask the dealer to do a leak down test, not to be confused with a compression test. This is the only way to say for certain if an engine is suffereing from excessive cylinder bore wear.
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