Engine doesn't idle as smooth as it used to

[nitehawk55]

A small vacuum leak is often overlooked as well .

 

[Dr_No]

Why hasn't anyone recommended replacing the fuel filter?

 

[yonyon]

Replacing the fuel filter would be silly. If the fuel filter had enough of a restriction to cause a problem at idle this thread would be about a car with a severe lack of power, blinking check engine light, and possibly some backfiring or stalling.

Check for a dirty MAF sensor and look for any signs that the balancer has slipped.

 

[Dr_No]

Im not going to argue with you, but a plugged fuel filter will not throw a check engine code or cause backfiring. Loss of power and stalling, yes. Rough idle, yes. To date since November 2008 i've replaced hundreds of fuel filters as an upper and lower technician. And I can say that with that experience, changing a fuel filter has fixed issues with rough idle and hard starting. It is a simple, and cheap item to replace.

 

[nitehawk55]

Lots of armchair "certified" OCD mechanics on here Dr_No , I retired from it myself back in the late 80's so I am behind with the technology in the cars today but some of the basics still apply with trouble shooting .
Rough idle can be a simple issue such as a vacuum leak (a car 14 years old likely has some rubber hoses going bad) , a fuel restriction (filter) or other issues as suggested , it's always a process of starting with the simple issues and working through each .
Dumping cans of injector cleaners and other mechanic in a can solutions or changing the motor oil (not sure how that causes a rough idle) isn't always the best place to start and some of these methods can cause other issues . Slow and methodical generally finds the fix . Finding a vacuum leak is either done visually , by ear or a can of WD40 or the like is your friend if you know what to do with it .

 

[Dr_No]

I never disagreed with that, just putting in a simple suggestion.

 

[Merkava_4]

Originally Posted By: loyd
This is just my opinion, but an air filter that never gets dirty is, to me, defective! Especially living in the Central Valley of California where there is lots of dust from agricuture.


The dirt hits the filter element and then falls off and collects at the
bottom of the air cleaner box. It's like a Teflon non-stick frying pan.