# Help - car chugging hard at low RPM



## Jack1616 (May 1, 2017)

Hi,

My car (Nissan Serena 2005 - automatic), has started stuttering and it’s getting worse and worse with time. At first it was very subtle and would only slightly happen when slowly accelerating from low speed (when it has to go just over 1500 RPM exactly). I managed to avoid this problem by putting the sport mode (in that case the car was accelerating faster and staying higher in the RPM so I wouldn’t get this shaking).
But it soon started chugging harder and harder and has started shaking at idle when in drive mode and in reverse, too. It feels similar to an engine that is going to stall or die. It’s like the engine is cutting for a fraction of second. The worse is when the car has warmed up and I wait at a traffic light or when I accelerate after having slowed down from turning, roundabout etc. 
It is now shaking a few times every single I accelerate slowly and the rpm are around 1500rpm. It also shakes when idling in drive mode; if I put the car in park or neutral the rpm goes a little bit higher and it doesn’t shake. It looks like the warmer the car gets the more it shakes. If I accelerate quickly enough (from low speed) the shaking sometimes doesn’t happen. It’s like if the car loses all power for a fraction of second. 
When driving at the same speed, especially when over 80km/h, the car is driving fine.
The problem started after servicing it, about a month ago and is getting worse the more I drive.
The following things have all been checked since the problem appeared:
•	Spark plugs and wiring
•	Vacuum lines
•	Ignition coil 
•	Oxygen sensor 
•	Oil and transmission level 
A mechanic has ruled out all of these options after checking them one by one. He scanned the car when driving and idling but it would show no error code. As the car shows no warning lights it is very hard to know where to look... He reckons it is probably an electrical issue. His ideas are maybe a crank sensor or fuel circuit. Any idea what it could be?
At this point I’ve spent quite a lot of money trying to find where the issue comes from. Is there anything else easy to check myself that I haven’t thought of??

Thank you so much for your help.


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