Idle Engine

Lately, when the RPMs drop below 1000 in my 2002 Santa Fe 2.4 $
cylinder, the engine seems to vibrate a bit more that normal. Also, the
engine seems to go from normal (how it was before I noticed this
problem) to a "jerky vibrate" back to normal. It doesn't vibrate a lot,
but it is noticeable to me.

I took it to a mechanic and said it was fine, but I'm not sure. Anyone
have any similiar experiences, or ideas on what it could be?

 

forgot a little additional detail...as soon as I rev over 1000 RPMs
(manual transmission) the smoothness returns to the engine, or even if
I keep it just above 1000 RPMs for a few seconds, the engine ticks over
quite smoothly...

there are 82000 miles on it also...

 

That's usually something simple and cheap, but can be a bear to find.

Could be a bad plug, a leaking plug wire, a vacuum leak, or a sensor
starting to go bad.

You didn't mention mileage, but an '02 is getting old enough for the
above "stuff" to happen.
-

Bob

 

Thanks for the reply...

I noticed it recently, then replaced an oxygen sensor (that had been
causing the check engine light to show for the past few months) but the
vibration is still there...

I asked the mechanic to check the spark plugs, and he said they were
good also...

I will bring it back and mention those things you stated - hopefully it
won't take too long to figure it out...I realise it might be
problematic to find, but it is starting to become an annoyance enough
for me to try find it at least!!

Thanks again for the reply.

 

The 2.4 engine actually transmits quite a bit of vibration at idle. If
your a/c compressor was cycling, that would explain why the vibration
changed.

Every once in a while, I see one with an EGR solenoid stuck closed,
causing the EGR vavle to remain open. You could be having this sort of
problem. In some cases, it doesn't set a check engine lamp.

If your mechanic has significant Hyundai experience, I'd say to trust his
opinion. If not, you may want to go by the dealer and have one of the
mechanics there sit in the vehicle and feel the vibration. The mechanics
there should know whether it feels normal-- they test drive these vehicles
regularly.