Re: 2005 GC- Mileage, Plugs

Well you don't really have a traditional Jeep engine, but you should be 
aware that most of the older Jeep 4.2's and 4.0's basically refuse to 
run on Bosch platinum plugs.  They work for a couple weeks, then foul 
and fail.  Not all of the engines. but a 'lot'.

I have fixed more bad idle problems (or as many) in 4.2 engines by 
simply tossing their new 'fancy' platinum plugs in the trash and going 
back to stock plugs, than I have by fixing that dreaded Carter BBD carb.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08.  Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com


Steve Richards wrote:
> Just checking in, the missus has the 3.7L and the specs say plugs every
30k. 
> She's really up in arms about the fuel prices. That's a topic for
another 
> day. Sure am glad I don't have a diesel!
> 
> She's getting 17-19 (80% hiway). I pulled the plugs (50K) and they are
the 
> original NGKs. We're the second owners and I am really surprised that
they 
> haven't been changed. Air filter is clean and we use 87octane.
> 
> Anyway, I am planning on replacing the plugs tomorrow with Bosch
Platinum 
> IIs. Pros/cons and your feedback would be appreciated.
> 
> TIA!
> 
> Steve