How much engine vibration is normal?

[Frankd1]

Hi everybody,
I noticed something yesterday that I found odd:

After driving around for a bit and with the Yaris warmed up I popped the hood and noticed the engine vibrating what I think is more than normal while at idle.
I know that with these motors as well as others there is always a bit of valve train noise which is normal but it was the vibration that caught me off gaurd.
I realize that a 4 cylinder engine is not going to run perfectly smooth but this seems like a fair bit -you can see it in the plastic cover over the top of the engine and it transmits to the air filter box and associated hoses as well as to the hose with the rad cap on it.

I dropped by the dealership this morning and pointed it out and the tech said that it was normal for these motors.

He sat inside and could not feel excessive vibration through the car - you can feel a bit if you put your hand on the passenger seat headrest but its not would I would call abnormal.

I also realize that these cars have their idle set relatively low but it just seemed odd thats all.

I know it would be difficult to tell without seeing it....any thoughts?

[yaris-me]

If you have over 20,000 miles, you might want to run a fuel system cleaner and clean out the fuel injectors. Don't use the cheap stuff. You get what you pay for.:thumbsup:

[Frankd1]

I only have 14000 miles on the car....

[yaris-me]

I only have 14000 miles on the car....

Worth trying if you're that concerned about the vibration. I use Gumout Regane or Chevron Techron. :smile:

[posaunemeister]

or you can just fill with part regular gasoline and part high octane gasoline. the higher octane won't do anything for performance gains on our small engine, but the idles and engine responsiveness will be noticeably smoother.

[why?]

The high octane would do a little something for perfomance, there's a reason all cars are tested with the highest octane. It is also feasible to see a small mpg increase as well. Neither is really a good reason to switch to a more expensive higher octane fuel though.

Have you ever had a 4 cylinder before? They do tend to vibrate more and run much less smooth than larger engines, and the Yaris especially seems to have a lumpier idle and more vibrations than most. The Yaris especially seems to dislike idling.

[Frankd1]

Thanks for all the suggestions and points of view! I am beginning to think that it is in fact normal and I just haven't noticed it on the this car before. My other vehicle is a 4 cylinder and it does vibrate a bit as well, but I just happened to notice it more on the Yaris - maybe because I'm not under the hood quite as much on my Yaris as my other older vehicle!!

I was at my parents place today and had a look at their 2007 Yaris (auto) while it was idling after it had warmed up and I noticed the same type of vibration - you could see it in the plastic engine cover and it transmitted through to the air filter box and the coolant hose with the rad cap on it.

Is the idle speed on the Yaris set a little lower than other cars?

I may add some Techron or Seafoam to my fuel on the next fill up.....