Cold High Idle
 

I have an 07 Civic Ex Coupe that idles rough & high when it's cold. The engine also "rumbles" when accelerating while driving. But after the engine warms up, it's fine. Any suggestions about what this might be? The Check Engine light hasn't come on. Thanks for any help!

Re: Cold High Idle
 

How high?
(Doesn't really matter, YOU can't do anything about it. Every bit of it is controlled by the computer.)

It is supposed to idle faster when the engine is cold. The colder it is, the faster it idles. Idle speed comes down as the engine gets heated up.

If the CEL isn't on, there is a 99.9% likelihood it is normal.



"Rough"ness and rumble that are strictly related to fast idle would be ok too.



Compare to an identical car before you think yours is broken.

Re: Cold High Idle
 

I have had this car since it was new in 2007 & it has never sounded like this. I have lived in the same area since I bought it, and I've kept up with all the scheduled maintence at the dealer. It's never sounded like this back-firing rumble before in the last 5 winters.

Re: Cold High Idle
 

I have been seeing the right motor mount bad causing all sorts of noisy rumbles, seems to have a little bit to do with temperatures when they first start making contact. Later on it does it all the time, worst in reverse and may be quiet while in drive.

See this post: https://www.civicforums.com/forums/1...ml#post4577741


They also make a lot of noise if someone leaves the oil fill cap off. Makes one hell of a mess too.


Does that help?

Re: Cold High Idle
 

Thanks, I'll take it to a mechanic Monday & have the motor mounts checked.

Re: Cold High Idle
 

It's better if you start with the actual problem, do not just say "check this and that".

SHOW the mechanic what it is doing wrong.
I'm dead serious about this.
This way everyone involved has a good chance of being on the same page.

Then you can bring up the motor mount idea, maybe print the pics of the good and bad mount from that post above and give it to him.


It really is a PITA to try to figure out what someone is talking about without having any other clues than someones written guess of what you meant during a phone call. Especially when the problem isn't obvious.


For all I know, it could just be the hood rattling.

Show them the problem.

HTH

Re: Cold High Idle
 

The problem with "showing" anyone what's wrong is it stops doing it by the time I get there. The best I can do is describe it.

Re: Cold High Idle
 

Oh....Ummm...That makes it tough.

I'm just thinking of all the times I get a work order that only says "Customer states there is a noise" with zero helpful hints. Then it's a guessing game, and YOU lose if it isn't an obvious problem. You also lose if a rookie gets the car.

I have also seen complaints that say "does it all the time" but really it only does it while going 70+ on a certain highway with the wind from the East, down through the holler over by Hoskins Creek......

Leave it overnight so they can check it in the AM, or drop it in the AM and make sure they can leave it sit long enough (afternoon?) for it to act up.

Give a scenario where you know it should act up, like: Drop it at 8AM (parked on a hill? Uphill or downhill?) and leave it sit until lunchtime, start the car, let it run for 4 seconds, put shifter in reverse, wait 2 seconds, then crank the wheel to the hard left and start backing up, at 10 feet it makes the noise....See what I am getting at? An exact scenario. (Every detail helps most of the time.)

Even better if you can go back later to show them after it has sat.



"A picture is worth a thousand words." Showing is better than telling.


Of course if the problem is super obvious, then I probably sound like I'm talking nonsense.

Re: Cold High Idle
 

The engine mount may be the rumbling problem, its the engine mount on the right. You can check this by placing your foot on the brake, move the car from Reverse to Neutral to Drive. If the vibration has improved significantly in Neutral, it is most likely that engine mount. The high idle may be caused by coolant loss. There is a problem with the engine block cracking on this model.