i have a 4.8L with 105,000 miles on it and i think i need to do a tune up. but i dont know where to start. i want to change my spark plugs with the e3 plugs but not sure. is there a better plug to get better mileage or is the e3 the one. and do i flush and clean the radiator/trans/rear end? any advice would be helpful. thanks in advance...

 

e3 are CRAP. Get some NGK or delco's. The stockers work just fine. IMO, if it ain't broke, don't fix it. 100,000 miles on these trucks in like nothing. Both my Dad's truck and mine are on stock everything besides the battery and oil changes.

 

this motor is in a '05 Yukon and i was just trying to get the best mileage out of it as i can hoping a tune up would help.....

 

you really won't get any better performance or mileage out of these engines with plugs/wires or anything IMO. Might pull a plug and see what it looks like

 

would it hurt to run some injector cleaner or to do the sea foam treatment through the engine??

 

injector cleaner really won't do a whole lot for you IIRC. Some swear by seafoam, some wouldn't use it if their live depended on it. I have never used it before so I can't give you any info. Do some searching and see if you want to use it

 

ok... thanks for your input......