Vibration while driving and bad gas mileage on Kia Sportage?

I’ve been driving my Kia Sportage for about a year, and it’s always had a vibration while driving and bad gas mileage. The vibration doesn’t seem to be in the steering wheel—it feels like it’s coming from the engine. The check engine light isn’t on, and so far, I’ve only had the fuel system cleaned. Any ideas on what could be causing this?

It sounds like it could be a misfire. Have you checked the spark plugs or air filter yet? Those are the first things I’d look into with issues like this.

NiroNavigator said:
It sounds like it could be a misfire. Have you checked the spark plugs or air filter yet? Those are the first things I’d look into with issues like this.

Good call on the spark plugs. When I had similar symptoms, replacing mine made a big difference.

How’s the fuel pressure? If the plugs and air filter are good, you might want to check that next.

Bright said:
How’s the fuel pressure? If the plugs and air filter are good, you might want to check that next.

I haven’t checked the fuel pressure yet, but I’ll add that to the list. Thanks for the suggestion!

A tune-up might help overall. Even if nothing’s obviously wrong, replacing plugs, cleaning the air filter, and checking the fuel pressure could clear this up.

Has the vibration been consistent, or does it get worse at certain speeds? That could help narrow things down.

OptimaPrime said:
Has the vibration been consistent, or does it get worse at certain speeds? That could help narrow things down.

It’s been pretty consistent. I haven’t noticed it changing with speed.

Check your motor mounts. A failing motor mount can cause engine vibrations that feel like they’re coming from the engine itself.