RPM flucturating
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#20
01-31-2019, 04:24 PM
Join Date: Feb 2004
Location: Denmark
Age: 49
Posts: 97
Rep Power: 24 
Will keep you updated, and again all inputs are welcome.
#22
02-01-2019, 09:50 AM
I have always heard of seafoam, but never bothered to learn how to use it. Anyone cares to educate me? You buy it in a can from wallyworld, then what? How much, where, for how long, what after that. Those sorts of questions. If you can demo on panamera with words, maybe a pic, would be awesome diy article. Thank you.
#23
02-01-2019, 10:06 AM
If this fluctuation is happening during steady state driving, the transmission clutch should be fully engaged so there is no opportunity for the RPM to jump. My guess is some electrical interference with the tachometer circuit (poor ground?) or the tachometer is going bad. I would find the ground wire for the cluster and tighten the ground connection. Will be $$$ to replace the cluster and not worth it.
#24
02-01-2019, 11:06 AM
Join Date: Feb 2004
Location: Denmark
Age: 49
Posts: 97
Rep Power: 24
I am not 100% that this does not come from the engine. Specially since there are no needle jumping at idle, and since it it most significant when driving slightly uphill with the same speed.
Throttle and injector cleaning is something that I could try. But there must be others who had the same issue and got it fixed.
#25
02-01-2019, 11:59 AM
If you drop down a gear or two when it starts fluctuating then hold the speed steady does the problem go away? If it stays steady then could it be that the PDK software starts to shift then aborts the gear change instantly. It’s hard to imagine the PDK would malfunction like this but it’s observed only on hills so maybe the PDK, control module or some electrical inputs to the module are the issue.
#26
02-05-2019, 02:53 PM
Completely different vehicle, but I had a similar issue with my motorhome years ago. RPM would bounce (more than you're seeing) but there was no change in the actual engine rpm. Ended up the alternator was going.
You might want to try getting a odbc reader that has real time stats and see what its reporting on the rpm, see if its steady and and confirm its not a motor issue
You might want to try getting a odbc reader that has real time stats and see what its reporting on the rpm, see if its steady and and confirm its not a motor issue
#27
02-16-2019, 10:47 AM
Join Date: Feb 2004
Location: Denmark
Age: 49
Posts: 97
Rep Power: 24 Completely different vehicle, but I had a similar issue with my motorhome years ago. RPM would bounce (more than you're seeing) but there was no change in the actual engine rpm. Ended up the alternator was going.
You might want to try getting a odbc reader that has real time stats and see what its reporting on the rpm, see if its steady and and confirm its not a motor issue
You might want to try getting a odbc reader that has real time stats and see what its reporting on the rpm, see if its steady and and confirm its not a motor issue
#29
11-17-2019, 01:57 PM
Join Date: Feb 2004
Location: Denmark
Age: 49
Posts: 97
Rep Power: 24 For now it seems to have solved the problem.
#30
11-17-2019, 04:05 PM
Registered User
Join Date: Aug 2018
Location: Anaheim, CA
Age: 43
Posts: 209
Rep Power: 14
Guys!!! I can help out here BIG time and get that idling down perfect! 1) Check your Air-oil Seperator - if you got a decent amount of miles on your 970, over 45k miles, check to see if you have a tear in the diaghram. Most of the bad idling comes from this, and or the leaking O-rings that connect the tubes to the unit. Change out the entire Air Oil seperator... there are no diaghrams sold seperately and Ive also already tried the Cayenne turbo ones with no luck, so thought id save you guys some time and money there, haha 2) Gunked Up Direct Injection Valves - do a CRC intake valve cleaning at each oil change... rough idling comes from this as well. 3) Dirty Map Sensor- particularly if you are using a BMS or any type of high-flow filter. The oils in the filter element can also cause the map sensor to not be as effective.... Clean with CRC MAP Sensor cleaner. 4) Throttle Body plate - if you havent cleaned your throttle body yet, this is another place in Panameras that cause bad idling 5) Spark Plug Gasket Seal - if you have a bad gasket here, you'll get blow by from the pcv system. Change out valve cover gasket and spark plug tube seals. 6) Clog PCV or leaking vacuum system - clean out PCV system with intake valve cleaner