Have had this honda since September has been great with 150k miles.

The problem is that randomly it will idle rough at a stop light. It shakes pretty hard and is easily felt in the steering wheel. This does not happen all the time and happens right after starting it up. Also it goes away after driving for a little. Also if you put the transmission into neutral (automatic) than it will get slightly better.

I am going to give it a tune up, but hoping it can be narrowed down to one thing. My concern is this issue progressively getting worse.

Thank you, Thomas

 

A tuneup is always a good idea if you don't know the history. You don't want to start troubleshooting a problem until you know the basics are good.

Two common problems with Hondas that affect idle are the fast idle thermo valve (FITV) and idle air control (IAC) valve. Lots of youtube videos covering these two. Just search "Honda idle" (or rough or surging idle) and you should find them.

A little more information would be helpful as there are several things that influence idle. Does the idle problem happen only when the engine is cold or does temperature not matter? Anything else going on at the same time? Did you get a CEL and pull codes?

 

When I hear "rough" idle I think of misfiring or something like that.

"Surging" idle behaves like a well-tuned engine being revved up & down.

 

I have only noticed it when engine was cold. Here in NY it has been below 40F on average as well, and i dont recall this issue back in warmer weather. No CEL, nothing else going on. I start up drive away, stop at stop light and it feels like a really violent vibration is going on. Easily felt in the sterring wheel and can be heard as well.

 

I dont notice much of a change in the RPM's during this. There isnt a misfire because i believe it would pull a code.

 

So is it like a harsh vibration?

Check out the rear engine mount. It's buried between the engine & firewall and it's vacuum-operated. It's supposed to get soft under the condition of idling in DRIVE or REVERSE.

Find a vacuum hose coming from the mount. Follow it to a solenoid valve & get ready to unplug the electrical plug from that solenoid.

Have a trusted friend hold the brake pedal while the engine is idling in D or R. You unplug that wire, and it should make a big difference in vibration.

If it doesn't make any difference, then look for problems.
- bad wiring to that solenoid?
- loose or broken vacuum hoses?
- mount itself is broken and/or doesn't hold vacuum?

 

Thanks alot, great feedback. Ill give it a check and post back when i get a chance.