Chris Doherty
Junior Member
- Joined
- Jan 13, 2019
- Posts
- 3
- Reaction score
- 0
- Location
- Williamsbureg, VA
- Ram Year
- 2012
- Engine
- Hemi 5.7L
Hi,
I have a 2012 Ram 1500 5.7L. About a month ago I had my spark plugs changed. I also had the coils changed. Right afterwards I started experiencing very poor gas mileage. Went from 16mpg on the highway to less than 12. It was also running a little rougher than usual. I thought it may be a bad plug. I pushed it hard to see if I could get the check engine light to come on. I did. Got a PO308 Misfire cylinder 8 message. I took it back to the mechanic who put in the plugs, and he told me I needed a new camshaft and lifters. I took his word for it (since I had just replaced the plugs and coils) and did that replacement. Got my truck back yesterday and Im still seeing the crappy gas mileage, rough idle and acceleration that seems to be more sluggish than normal. The check engine light has not returned after replacing the cam and lifters. But I haven't pushed it like I did a month ago. I replaced the spark plugs with NGK 92174. Ive read that you want the original copper. And that is what I thought I bought. Did I get the wrong ones? Could these spark plugs be the culprit? I have a K&N Air filter that was cleaned a few months ago. Does anyone have any suggestions as to how to diagnose where these issues are coming from and where I should start looking?
Thanks
Chris
I have a 2012 Ram 1500 5.7L. About a month ago I had my spark plugs changed. I also had the coils changed. Right afterwards I started experiencing very poor gas mileage. Went from 16mpg on the highway to less than 12. It was also running a little rougher than usual. I thought it may be a bad plug. I pushed it hard to see if I could get the check engine light to come on. I did. Got a PO308 Misfire cylinder 8 message. I took it back to the mechanic who put in the plugs, and he told me I needed a new camshaft and lifters. I took his word for it (since I had just replaced the plugs and coils) and did that replacement. Got my truck back yesterday and Im still seeing the crappy gas mileage, rough idle and acceleration that seems to be more sluggish than normal. The check engine light has not returned after replacing the cam and lifters. But I haven't pushed it like I did a month ago. I replaced the spark plugs with NGK 92174. Ive read that you want the original copper. And that is what I thought I bought. Did I get the wrong ones? Could these spark plugs be the culprit? I have a K&N Air filter that was cleaned a few months ago. Does anyone have any suggestions as to how to diagnose where these issues are coming from and where I should start looking?
Thanks
Chris