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Thanks, (more) (archive)

[ Follow Ups ] [ 5-series (E34) Message Board ] [ Msg. Board FAQ ]

Posted by dudel on July 30, 2001 at 12:04:19:

In Reply to: Re: 530i rough idle posted by Rodney on July 30, 2001 at 10:13:33:

Thought you were in Atlanta based on the GSU address!

Ok, reason I asked:
1) Part of the country would affect the amount of sulpher in the gas and therefore agravate a nikasil problem

2) Age/miles could affect the ICV (idle control valve) or leaky hoses/gaskets

There is a writeup on the website. It tells you how to determine the type of block you have by checking the casting/part numbers on the block. The northeast states had the worse concentration of sulpher (sorry) while the left coast had the lowest concentration. Southeast is somewhat in the middle. Being as your car lived up north, I would certainly get the nikasil issue worked on. A rough idle is only one indicator. The techs at Global Imports or Chris BMW should be able to tell you what engine you have (and if it's been replaced based on your VIN) IIRC, you can still ask for a free leakdown test.

If it turns out that you block has been replaced (hopefully with an alusil, although early on some were replaced with another nikasil).

If the block can be ruled out, then I'd check the ICV. As it turns out (Joe O's assumption was correct)the ICV is used to maintain steady state idle. If it's sticking or not regulating correctly, it will affect the idle. I've not heard (nor had any luck myself) cleaning the ICV. Bentley's had a good test of them. If you need one, get a new one.

Another thing that can affect your idle would be a vacumm leak. With 111K+ miles on it, I'd check the hoses in the intake patch and the gaskets on the intake manifold for leaks.

We have a great independant in Atlanta called Harrison Motorsports. You can reach David Harrison at 678/822-0350. They are located near Andretti Speedlab in Alpharetta. They are real BMW fanatics and can take care of you very reasonably.

Hope this helps,

95 540i
95 ///Miata


I am in Atlanta however the Carfax report shows a history in Pennsylvania, Virginia, and New Jersey.
The car has 111k miles. Other than the rough idle, the car looks and drives like new.

How many miles and where in the country are you?

Don - Atlanta
95 540i
95 ///Miata

My 1994 530i has a rough idle. It slightly rocks the car at idle and gets worse when the a/c compressor comes on. I have been to and understand what my problem may be. Is there anyway to know what type engine is in the car - I am not the first owner. BMW says they do not have a national data base and there is no way to tell whether the engine has been swithched out? Any suggestions for identifying M60 vs M62? Ideas about other potential causes besides leakdown (maybe I'm in denial), will the problem get worse if unaddressed (I'm now using Amoco Ultimate gas), will it get worse in colder weather, ideas to reduce roughness??? Ideas for less expensive repair than block replacement?

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