if u think the air filter is going to make a difference, just take yours off and drive to the ice cream shop. youll know b4 u get back

 

We've got 80k miles on our replacement head, durability isn't an issue when the valves/seats or whatever are in spec. I also just replaced the plugs at the 100k mark and they all looked pretty good except for the gap which averaged over double what's printed in the owner's manual. The decent condition of the plugs are hopefully a good sign regarding how our engine is holding together.

If you usually use a top tier gas brand you can skip the fuel additive routine because it's already mixed in the gas. Google "top tier gasoline" for the list of brands that qualify for the standard.

IMO, the best way to handle fuel injectors is to remove them and have them cleaned and tested by a shop. The in-vehicle cleaning treatment seems like a questionable practice to me.

 

Worked for me, and according to other posts, it has worked for others as well.

I've also switched to top-tier gas and my cyl 5 misfire CEL has not come back.

Not that this is the OPs issue, but worth a shot.

 

my h3 jus hit low gas so im gonna go out and fill it and keep the 91 octane going threw its veins, hopefully that does the trick, im sure itll boost it alil and hopefully fix the problem

 

I have an '06,rough idiling/vibration for a while when stopped , later one day engine light came on. Code: Cylinder #5 missfire .. Head REplaced under warranty @ 27k miles ...
Common problem on early H3's I guess.. Pressure test it !! Your best,fastest answer!

Good luck!

 

i have 66k miles on my 06, i dont have warranty anymore
if it is the bad head, im gonna call raising hell and see what happens, hopefully they crack and help me out.... if thats the problem tho....

 

Have u cleaned the throttle body as suggested before ?
I had the rough vibration and I had to change the engine mounts [ 63K]
one of them was totally bad..and also checked the throttle body which was black inside..after this cleaned and the new mounts, the vibration is gone by 90%..I guess u cannot eliminate vibration 100% from a 5 cyl motor

 

don't exactly know how to clean the throttle body.....
how much do was it to clean up and everything?

 

You guys are scaring me with this cracked head stuff. I had the #5 coil go out, replaced and no problems since. That was at 65,000. I'm at 90,000 now and still knocking on wood. I hope my head wasn't made on a Monday or a Friday. Any other heads other then factory