Hello. I've noticed from time to time that my car vibrates just a bit when im at a stop light. THis doesn't happen all the time. Sometimes i've noticed my RPMs at around 550-600 at a stop light. other times i've noticed my RPMs at 500 and I can feel a slight vibration. The CEL does not come on when this happens. Is this normal? Thanks.

 

My guess, dirty throttle bodies.

 

How does one properly clean the throttle bodies on a G37?

 

 

I use to have that problem with a fuel injected Honda Accord in the winter. Id add a bottle of injector cleaner in the start of winter and it would clear up the problem till the next winter.

 

Update - I cleaned the throttle bodies about 2 hours ago. I'd say it took me about 1 hour since this was my first time doing this on the G. Thanks @hurleyguys for posting the video. This really helped a lot. I made sure I didn't touch the butterfly plates and blasted them with throttle cleaner on both sides of the TB and wiped around the plate. I did not disconnect the battery or the TBs. Cleaned the gasket that goes between the TB and the plenum. Also, I covered the MAF sensors to protect them from dust/TB cleaner/grime. After putting everything back together, I did notice a difference in idling, which was smoother. Throttle response did improved a bit as well. I really couldn't do fast runs because of traffic so I'll give this another shot on my way to work tomorrow. So far everything seems good. No SES light.

 

i prefer to just remove the tb completely and sit down on a table and thoroughly clean it rather than do it the way the guy in the video did