RPM dancing when coming to a full stop

[tirzaman]

Days ago, I bought a 2010 M35 pre-owned. I noticed that while I'm coming to a full-stop (stop light, etc) the RPM goes down as it should but then shoots out (from 1k to 1.2k) and makes me feel like I was bumped from behind. Sometimes, this happens quite a few times as I'm slowing down and preparing to stop. The car jerks ahead while I have my foot on the brake pedal.

Has this happened to anybody else and if so, what's the problem/solution?

[svard75]

Does it feel like its bogged down during acceleration? You've got the uprev engine with two tbs and two air filters, maf sensors. Have a look at the air filters first. If they are okay I would attempt to relearn the idle tb relearn procedure maybe one of the tbs butterflies were touched and are out of sync?

[finikM35]

My 07 did that too was scary sometimes. As im about to stop RPM jumps and car lunges forward. It happened after i uploaded tune (osiris). Relearn didnt help but it went away after i removed the tune. After few changes to the tune seymore got it perfect and it never happened again.

[zags]

Days ago, I bought a 2010 M35 pre-owned. I noticed that while I'm coming to a full-stop (stop light, etc) the RPM goes down as it should but then shoots out (from 1k to 1.2k) and makes me feel like I was bumped from behind. Sometimes, this happens quite a few times as I'm slowing down and preparing to stop. The car jerks ahead while I have my foot on the brake pedal.

Has this happened to anybody else and if so, what's the problem/solution?

Hey Tirzaman, welcome and congrats on ur purchase. This is apparently a known issue for the 09/10 M35's, since they are the only Y50's (that I am aware of) that had the 7 speed transmission. In fact I found a TSB issued on the very issue and the fix was to reflash the ECU, and according to people that had the reflash this fixed the problem and even seemed to increase performance for them.

Another symptom of the problem can be immediately after start-up your car doesn't stay on and dies, and/or there can hard downshifts into 3rd or 2nd while in full auto mode coming to a stop.

My M35 does this too, I've been living with it for more than a year, when I bought the car CPO. I've never gone into the dealer to have them test for the TSB fix since I plan on having my M35 tuned via the UpRev program. which should also do the trick.

[EniGmA1987]

I think it is normal for a lot of the bit older years to do something similar to this. My 06 usually jumps a couple hundred RPM, but it doesnt feel anything like "someone bumping me from behind" like you say. I remember someone else complaining about it and when the car was taken to the dealer for dealer programmed an ECU (or TCU?) update that had come out to fix the issue. Unfortunately the update service isnt a requirement so they do charge customers to do it and I have no idea if it applies to the 2010 models. These were for the 06-07 that I know it is available for.

[tirzaman]

Does it feel like its bogged down during acceleration? You've got the uprev engine with two tbs and two air filters, maf sensors. Have a look at the air filters first. If they are okay I would attempt to relearn the idle tb relearn procedure maybe one of the tbs butterflies were touched and are out of sync?

I don't feel anything wrong with the acceleration. Are you saying that this behavior is normal because I have the two certain TBS for engine uprev? Does this model have two air filters or is this yet another option that's on my car? What are the maf sensors?

[tirzaman]

My 07 did that too was scary sometimes. As im about to stop RPM jumps and car lunges forward. It happened after i uploaded tune (osiris). Relearn didnt help but it went away after i removed the tune. After few changes to the tune seymore got it perfect and it never happened again.

Could you be a bit more specific about the tune upload? What's that and what exact changes did you apply to the tune to make it go away?

[tirzaman]

Days ago, I bought a 2010 M35 pre-owned. I noticed that while I'm coming to a full-stop (stop light, etc) the RPM goes down as it should but then shoots out (from 1k to 1.2k) and makes me feel like I was bumped from behind. Sometimes, this happens quite a few times as I'm slowing down and preparing to stop. The car jerks ahead while I have my foot on the brake pedal.

Has this happened to anybody else and if so, what's the problem/solution?

Hey Tirzaman, welcome and congrats on ur purchase. This is apparently a known issue for the 09/10 M35's, since they are the only Y50's (that I am aware of) that had the 7 speed transmission. In fact I found a TSB issued on the very issue and the fix was to reflash the ECU, and according to people that had the reflash this fixed the problem and even seemed to increase performance for them.

Another symptom of the problem can be immediately after start-up your car doesn't stay on and dies, and/or there can hard downshifts into 3rd or 2nd while in full auto mode coming to a stop.

My M35 does this too, I've been living with it for more than a year, when I bought the car CPO. I've never gone into the dealer to have them test for the TSB fix since I plan on having my M35 tuned via the UpRev program. which should also do the trick.

Zags, thanks for your welcome! What is the UpRev program? Can one use this or do a TSB update to the latest version to fix the issue? I appreciate all the answers to my issue but, honestly, I'm at a loss understanding their meaning. UpRev, tune TSB, reflash ECU, etc. Does my car have a special UpRev TSB which is the cause of my issue or does the UpRev TSB should fix my problem? Also, what about a general upgrade to the latest TSB available? Would that fix all the problems??

[tirzaman]

I think it is normal for a lot of the bit older years to do something similar to this. My 06 usually jumps a couple hundred RPM, but it doesnt feel anything like "someone bumping me from behind" like you say. I remember someone else complaining about it and when the car was taken to the dealer for dealer programmed an ECU (or TCU?) update that had come out to fix the issue. Unfortunately the update service isnt a requirement so they do charge customers to do it and I have no idea if it applies to the 2010 models. These were for the 06-07 that I know it is available for.

Thanks. I have a feeling that I need to go to the dealer and have them apply the latest TSB. An interesting point is that my average gas consumption is extremely high based on the data available in the computer (when I bought it, it was around 15mpg - UNBELIEVABLE!). Now, it inched its way up to probably 17-18mpg. I have two G35's (coupe and sedan) and I know that the mpg for those cars is not the greatest but 15mpg for a M35 is awful.

[svard75]

I don't feel anything wrong with the acceleration. Are you saying that this behavior is normal because I have the two certain TBS for engine uprev? Does this model have two air filters or is this yet another option that's on my car? What are the maf sensors?

Sorry for speaking techaneeze to you. Your engine under the hood is a newer model of Nissan 3.5 liter engine. If you open your hood you should notice that there are two larger looking pipes coming to the front from the rear. They are identicle in size and look. At the front of your engine and where those two pipes end are the air filter boxes. Inside of these two boxes is where your air filters are. You will likely have to remove the two plastic engine covers to see what I am talking about.. The maf sensors are sitting inline with those pipes. The TBS is short for throttle bodies. You have two of them. TSB is technical service bulletin and is basically a document that Nissan releases indicating the proper procedure to fix known issues or previously reported larger quantity and scale issues. They also contain instructions on how to address vehicle recalls.

As others have mentioned and based on the age of your vehicle take it to the dealer and have them service it. You may want to be proactive and review all TSB on your car. http://www.safercar.gov/Vehicle+Owners

[tirzaman]

Thanks for your detailed explanation. I'll check the TSBs and probably will take it to a different dealer for service since the one I bought the car from, indicated that they already did a thorough check (they probably just changed the oil). Thanks, again. I hope this will go away after my service visit.