Stuttering gets worse when defrost is on?

Tiny
TMERRITT
  • MEMBER
  • 2015 MITSUBISHI OUTLANDER SPORT
  • 96,000 MILES
Car stutters sometimes. Recently I noticed stuttering gets worse when defrost is on but not when heat is on. The husband would put it in neutral if at a stoplight and stutter and idling will calm down.
Saturday, January 4th, 2025 AT 1:23 PM

3 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Yep, when the engine is under load it will misfire because this is when the ignition system is under stress. I would do a full tune up with spark plugs and ignition coils with are a common failure, also I would service the throttle bore, here are two guides to help walk you through the repair and instructions for your car in the images below.

https://www.2carpros.com/articles/how-to-tune-up-a-car-engine

and

https://www.2carpros.com/articles/throttle-actuator-service

2.0L 4-cylinder (4B11) NGK ILKR7E6 (Iridium) 0.039 - 0.043 in (1.0 - 1.1 mm)
2.4L 4-cylinder (4B12) NGK ILKR7B8 (Iridium) 0.039 - 0.043 in (1.0 - 1.1 mm)

Check out the images (below). Please upload pictures or videos in your response of any problems so we can see what to help you with.
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Sunday, January 5th, 2025 AT 2:54 PM
Tiny
TMERRITT
  • MEMBER
  • 2 POSTS
Thank you so much.
I figured it needed a tune up.
In my state a full tune up can be expensive.
I will have them focus on spark plugs and coils.
Was this
answer
helpful?
Yes
No
Sunday, January 5th, 2025 AT 2:56 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Sounds good, I would have them do the throttle bore service as well.
Was this
answer
helpful?
Yes
No
+1
Monday, January 6th, 2025 AT 9:52 AM

Please login or register to post a reply.