Sputtering at stop light

TNAUCKE

MEMBER
2006 CADILLAC DEVILLE DTS
128,000 MILES

My car is rough at stop lights. There is no check engine light. It sputters not like it is going to stall but it is jumpy. I have changed the coil packs, spark plugs, fuel injectors, the air filter, and cleaned the max air sensor. I also checked the brakes and the brake system. It is running rough but it happens when I come to a stop, I can put it in neutral and it sits calm the rpm's are not jumping either.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,190 POSTS

Welcome to 2CaroPros.

If it only happens stopped, in gear, and the check engine light isn't on, it doesn't sound like it is a malfunction. However, anything is possible.

Based on that, the first thing I suggest checking are the motor mounts. If you have a collapsed engine or transmission mount, you will feel it under the conditions you mentioned and not necessarily in neutral or while driving.

First, take a look through this link. It discusses the most common causes of a misfire at idle or a vibration at idle. See if anything is helpful.

https://www.2carpros.com/articles/engine-vibration-at-idle

https://www.2carpros.com/articles/vibration-noise

Here is a link that discusses how a motor mount works:

https://www.2carpros.com/articles/how-a-motor-mount-works

Let me know if any of this helps or if you have other questions. Also, make sure something like the exhaust isn't touching the underside of the vehicle when you feel the vibration.

Take care,
Joe