Engine missing on smooth road?

LROD50

MEMBER
2011 SUBARU OUTBACK
3.6L
6 CYL
4WD
AUTOMATIC
41,600 MILES

While driving down a smooth road, I can feel the engine missing. Not all the time, just sometimes. I can feel it in my foot and my body. When asked, others say they can't feel anything. To me, it is very noticeable. I asked the Subaru dealer to check it out but they got out of it by saying, that test doesn't happen until 80,000 km. I know I should have demanded a testing of the fuel system and the spark plug cables. I believe the fuel system is a reach because it doesn't happen when I punch it when passing other cars. So the fuel bowl is not empty enough to cause a lack of fuel. My guess is it's the cables or plugs themselves. One or more. I know my best bet is to have it tested by my Subaru dealer. But maybe a mechanic on here can offer their 2¢. Thanks

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
47,702 POSTS

If the engine was misfiring it would have the check engine light on in most cases, at the least a scanner should the misfire history, here is a guide to help us see what going on:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Also, I have seen the EVAP purge solenoid leak which can cause a random misfire at highway speeds. Here is the location of the valve so you can remove it to see if you can blow through it which you should not be able to. Also, please go over this guide as well:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

At 41K it would be time for the spark plug replacement so that could help as well, here is a guide to help and instruction in the images below as well. You could have moisture in the ignition coils so look out for that and replace any coils that look like they are arching. Check out the images (below). Please upload pictures or videos in your response to the problem so we can see what's going on.

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