RPM fluctuating with cruise set (steady state driving)

turbo6justin · 03-09-2020, 01:31 PM

Trying to track down an interesting one here with a family 2007 328i 6sp manual (183000 miles). It drives great, but with the cruise control set or during any other steady state driving the rpm's fluctuate on the gauge about 100-200 rpm's. You can't really even feel it in the car but it is annoying to watch.

It had a oil change recently and they broke the center piece on the filter housing cap which was causing a vanos code till I looked at it. The solenoids are very clean and I just cleaned the filters thinking that might be it. There was some junk in them too. The filter cap was obviously replaced. No codes of any sort after the vacnos was sorted out.

Any ideas? There is also a slight idle rpm fluctuating but not out of the ordinary.

This one has me stumped and I'd like to fix it just for peace of mind more than anything at this point.

TunafishE93 · 03-09-2020, 04:04 PM

Its just how the gauge works.. Don't look at it.. Mine does it but under logging its not there.. But I know what you are talking about. The needle moves slowly..

03-09-2020, 01:31 PM	#1
turbo6justin New Member 4 Rep 27 Posts Drives: E90 328i 335i E93 335i Join Date: Nov 2018 Location: Wisconsin iTrader: (0)	RPM fluctuating with cruise set (steady state driving) Trying to track down an interesting one here with a family 2007 328i 6sp manual (183000 miles). It drives great, but with the cruise control set or during any other steady state driving the rpm's fluctuate on the gauge about 100-200 rpm's. You can't really even feel it in the car but it is annoying to watch. It had a oil change recently and they broke the center piece on the filter housing cap which was causing a vanos code till I looked at it. The solenoids are very clean and I just cleaned the filters thinking that might be it. There was some junk in them too. The filter cap was obviously replaced. No codes of any sort after the vacnos was sorted out. Any ideas? There is also a slight idle rpm fluctuating but not out of the ordinary. This one has me stumped and I'd like to fix it just for peace of mind more than anything at this point.
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03-09-2020, 04:04 PM	#2
TunafishE93 Major 418 Rep 1,152 Posts Drives: BMW 335i Join Date: Dec 2019 Location: NV iTrader: (0)	Its just how the gauge works.. Don't look at it.. Mine does it but under logging its not there.. But I know what you are talking about. The needle moves slowly..
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