Hello,

I've recently bought an automatic 2008 Honda Accord Coupe EXL V6, when I drive down a flat stretch of road at around 40-70 KM/H with the RPMs around 1200 the RPMs begin to oscillate. The engine speed drops to 1200 then back to 1250, drop to 1200 then back to 1250, etc. This occurs in roughly one second intervals. You can feel and hear this oscillation when it happens and you can watch the RPM needle moving back and forth.This doesn't happen when the car is idle, just while driving. Another thing I noticed is that during some launches, the car would have an occasional jerk, I'm not sure if this has any correlation with the fluctuation. Timing belt was said to have been changed within the last 15,000 KM, as the previous owner showed me that he bought it from a used dealership about a year ago and they mentioned that the timing belt was serviced. I'm wondering if anyone may know what factors could be causing this. Has anyone heard of this problem? Let me know if there are any other details I can give.

Thank you

 

I have the 2008 Accord 4 cylinder /... in contrast to your v6. If I was personally tackling your issue, I'd start with cleaning the throttle body valve (w specific spray cleaner, or possibly electronic spray cleaner) , and then go through the the "Idle relearning procedure" which you can google and look up. You Tube could supply some specifics with video.

Retired Bill

 

I know I’m years late to this, but did you ever figure out the problem? I’m having the same issue.

 

Automatic? Very likely the torque converter lockup clutch is slipping.

Fix is a new torque converter.

 

Had this problem after i replaced the head gasket on my 2.3l 4 cyl.
my problem was caused by my own lack of awareness when buying a part. I accidentally bought the next generations 'oil sending unit'/'oil pressure sensor' ( whatever you want to call it really). I swapped it back out (half broken) and presto problem solved after replacing it with a new one.

My car's symptoms were relevantations around 3500 rpm +/-700ish rpm. As well as, a violent jerking motion and shaking In the vehicle.