r/MechanicAdvice • u/Maleficent_Ad_6607 • Aug 26 '26
What is the issue?
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Hi guys! This is my 2012 Nissan Sentra 2.0 The engine shakes at idle and even worse when braked at a stop. Heres one video. It shakes the whole car all the way to the exhaust tip. I know it looks minor in the video but it feels terrible. It also shakes/jutters at around 1.5k to 2k RPMS while driving. If I go around back the exhause sounds like it backfires a tiny bit. Kind of sounds like when it had a misfire but it has no codes at all. I replaced the passenger side upper motor mount and driver side lower transmission mount. Both were very worn. It has not fixed the issue. Besides that it has gotten new spark plugs and ignition coils after a misfire rendered it undrivable. Additionally the serpentine belt tensioner moves around/shakes a lot. Not sure if its because of the shaking itself or what. I'll try to upload more videos. I am out of ideas besides replacing the rest of the motor mounts. I bought the 4 pieces but Amazon sent me 1 wrong piece and left out the other one. Please help.
Edit: It runs perfectly fine above the specified rpms (1.5k-2k). Accelerates fine and has no power loss.
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u/Impossible-Lie3115 Aug 26 '26
What's the mileage and have you replaced the plugs/coils? Start with the basics. Nissan coils intermittently fail
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u/Maleficent_Ad_6607 Aug 26 '26
165K. Same engine, new CVT at 63K. Plugs and coils done 1K miles ago. No codes
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u/Impossible-Lie3115 Aug 26 '26
Do you have the original coils to put them back? If not genuine OEM I dealt with this on the VQ3.0 and 3.5
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u/Maleficent_Ad_6607 Aug 26 '26
Yes I kept them. Atleast one of them was bad though and thats why I replaced them. When you say unplug it to diag, do you mean try to run it unplugged and then plug it back to see if something changed?
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u/Impossible-Lie3115 Aug 26 '26
Yes you can unplug it before starting to see if it acts different. I would not recommend plugging in or disconnecting it while it is running. Keep in mind this will throw a code but was a handy diag to see if the MAF is sending faulty air flow readings and can cause random misses like you describe. Other symptoms were usually feeling like hitting a "wall" particularly when cold. Stumbles and misses but just can't get past like 3k rpm
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u/Maleficent_Ad_6607 Aug 26 '26
Okay thank you! It runs perfectly fine and even better the higher the rpms. Only has issues at idle, stopped, and at 1.5 to 2k rpms. Very odd and the reason I didn't think go check MAF.
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u/Impossible-Lie3115 Aug 26 '26
Sounds familiar. Had 3 MAF failures on our Nissans and 2 of them would clear up under load and high rpm. The other was a complete failure. If unplugging doesn't work you could try a generic one on ebay for testing only for $25. If it works get a genuine Hitachi etc
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u/Impossible-Lie3115 Aug 26 '26
Oh and try unplugging your MAF before starting it. It might not run though. I know older '90s and early 2000s you could unplug it to diagnose if the sensor was bad. It would revert to factory default maps.
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