bouncing RPM on highway
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2009 C350
bouncing RPM on highway
Sorry to bring this issue back up i know it has been covered a bunch but i just cant seem to sort mine .. i own a c350 2009 and the issue came like 3 or 4 months ago. I replaced the torque converter but it didnt solve the issue. I dont have any fault lights what so ever. I even brought the car to a certified mechanic with Star but still no errors were stored. The issue is basically just an RPM that bounces up and down when driving on highway and for the last month i have been feeling a slight hesitation when accelerating from the ground. Cleaning the throttle body + airmass sensor didnt solve the issue as i tried that before. I hope some one can help before i get rid of the car which i really dont want to
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2009 C350
Originally Posted by tekfoc
Probably need to replace fuel filter
Also pick up a can of BG44K fuel cleaner
Also pick up a can of BG44K fuel cleaner
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The fuel filter should be fine at your mileage, and it was just discussed recently that it is now advised to be an item that never needs replacing. Sure, throw in a fuel injector cleaner, but that shouldn't resolve this issue either unless you've been using very low grade gasoline.
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I would assume someone with a STAR diagnostic scanner could live stream data while driving on the highway to at least give an idea of where the problem could be. Throwing parts at it will be expensive, specially a torque converter. If you're going to throw parts at it, change things that will benefit the car regardless like spark plugs, fuel injector cleaner and cleaning the MAF sensor. All these don't cost much and will improve the car regardless if they are the issue or not, at least those would be ruled out.
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From: Lebanon
2009 C350
i forgot to mention that i cleaned the MAF sensor, got new oem spark plugs and air filters too, it did improve a bit . We also tested the Intake manifold on Star and it gave normal results regarding the pressure. Im really starting to think its either a vacuum leak or a fuel kinda stuff tho i only put premium fuel.
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2008 C350 Sport 4Matic Swap
i forgot to mention that i cleaned the MAF sensor, got new oem spark plugs and air filters too, it did improve a bit . We also tested the Intake manifold on Star and it gave normal results regarding the pressure. Im really starting to think its either a vacuum leak or a fuel kinda stuff tho i only put premium fuel.
That is strange, did you also check if the torque converter lock up switch was working properly via STAR? It could be the solenoid that locks the torque converter located in the valve body. If you already replaced the torque converter, I would ask your mechanic to test the lock up solenoid.
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That is strange, did you also check if the torque converter lock up switch was working properly via STAR? It could be the solenoid that locks the torque converter located in the valve body. If you already replaced the torque converter, I would ask your mechanic to test the lock up solenoid.
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It would be easy if the car always gave codes and told you what was wrong. Unfortunately, that isn't always the case which is why mechanics need to diagnose specific values and see if they are in spec.
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Originally Posted by ltwargssf
That is strange, did you also check if the torque converter lock up switch was working properly via STAR? It could be the solenoid that locks the torque converter located in the valve body. If you already replaced the torque converter, I would ask your mechanic to test the lock up solenoid.
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Don't worry, if it comes to the solenoid being bad, its not the whole valve body that needs replacing but that solenoid alone.
As you see from the video, they are quite easy to replace.
New, they're around 200$ each. If I were you, I would drop the valve body, get a used Torque converter lockup solenoid and see if the issue changes. It would make for a nice transmission flush at the same time + It would be a great time to clean the conductor plate with electrical cleaner while its out to extend its life.
Last edited by W204Motorsports; Sep 26, 2018 at 01:56 PM.
