I’ve got a 2005 Kia Sorento that’s throwing a random misfire code along with misfires on cylinders 2 and 5. I’ve already changed the spark plugs and coils, but I’m still getting the same codes. Anyone have an idea of what could be causing this? I’ve tried cleaning the fuel injectors with sea foam a few times.
Sounds like it could be a compression issue. Have you checked that yet?
Umbrielle said:
Sounds like it could be a compression issue. Have you checked that yet?
No, haven’t done that yet. What should the compression numbers look like?
Umbrielle said:
Sounds like it could be a compression issue. Have you checked that yet?
No, haven’t done that yet. What should the compression numbers look like?
It should be between 164 and 185 PSI. If it’s low, you might want to do a leak-down test to figure out if it’s a valve or piston rings issue.
Umbrielle said:
Sounds like it could be a compression issue. Have you checked that yet?
No, haven’t done that yet. What should the compression numbers look like?
What’s a leak-down test?
@fabgise
It’s a way to check where air is leaking from if your compression is low. Helps figure out if the issue is with the valves or the pistons.
Did you try swapping the fuel injectors to see if the misfire moves to different cylinders?
StingerStar said:
Did you try swapping the fuel injectors to see if the misfire moves to different cylinders?
Not yet, but that’s a good idea. I’ll give it a try.
Also, check the intake manifold flapper on those two cylinders. If it’s damaged, it might be restricting airflow.
BrianCopland said:
Also, check the intake manifold flapper on those two cylinders. If it’s damaged, it might be restricting airflow.
Didn’t think of that. I’ll add it to my list. Thanks!
Had a similar issue with my Sorento. It was low compression on one of the cylinders, turned out to be a valve issue.
gabu said:
Had a similar issue with my Sorento. It was low compression on one of the cylinders, turned out to be a valve issue.
Did you have to replace the heads?
gabu said:
Had a similar issue with my Sorento. It was low compression on one of the cylinders, turned out to be a valve issue.
Did you have to replace the heads?
Yeah, after confirming with a leak-down test, we had to replace the heads. Fixed the issue though.
Make sure to check compression before diving too deep into replacing parts. Could save you some time.
Dexter said:
Make sure to check compression before diving too deep into replacing parts. Could save you some time.
Thanks for the tip, I’ll start there.