Car not idling well


#1

Hello fellow car owners.

I have a great vw 2008 rabbit with 115,00 miles on her. I just completed a round trip from boston to san francisco. On my way back during terrible stop and go Washington DC traffic…I noticed the car started to rev a bit. After that the idle has been rough with some light shaking. No engine light, but it does sound almost like it is choking a bit. Not extreme…but definitely not the smooth engine sound I had. I am guilty of NEVER HAVING MAINTENANCE on her…so I had new spark plugs put in and a new air filter. The problem is less…but the idle is still on the rough side. Any ideas ?


#2

With “no maintenance” for over 100k miles, the possibilities are almost endless, but since the plugs & air filter have been replaced, I would look next at the Idle Air Control valve, which is likely to be very dirty.


#3

I hope that with that many miles , you at least had a few oil changes.
You should look at your owners manual, or find one on-line if you don’t have one, and get into a routine of maintaining this vehicle.
Take your car back to the person that replaced the plugs and have them check the Idle air control as VDCdriver suggested. While the mechanic is in there ask if he will check for any vacuum lines that came off.
If you continue to not maintain this car it may only take you another 10,000…20,000 miles. But if you start with some basic maintainence it might go another 100,000 miles.


#4

You might also check for a vacuum leak. They can cause your symptoms as well.

An acquaintance of mine DROVE his Suzuki SX4 to the shop making a horrible noise. He admitted to not only not CHANGING the oil, but not CHECKING it for 25,000 miles. DUH! The noise was caused by a rod hanging out of a small hole in the block. Please learn from his experience, not your own.


#5

outdoor75 wrote:
I am guilty of NEVER HAVING MAINTENANCE on her

This approach often results in saving a few dollars now and spending a pile of money later on a problem that could have been avoided. I urge you to reconsider.


#6

According to my “lookup”, this is a distributor based system. I’m surprised you got this far with the same distributor cap and rotor. I think it’s time for a tuneup.


#7

Not to nitpick, but according to my information, this car has an electronic throttle body and coil on plug ignition

That said, I think it would be wise to clean the throttle body and replace the fuel filter


#8

“The noise was caused by a rod hanging out of a small hole in the block.”

The Suzuki “Low Oil Alarm.”


#9

I’d start with looking for a vacuum leak, especially if the idle is a little on the high side, 900 to 1100 rpm instead of the normal 750. If the air filter has not been replaced according to the maintenance schedule, I would also have the MAF sensor cleaned.

Check your owners manual to see if a valve lash check is on the maintenance schedule, then get that done ASAP. If the valve lash is too small, it could burn the valves in short order, and that will be expensive to fix.