I have a grand cherokee and when i give it gas it feels as if its not getting as much power, sputtering in a way. This started on my way home from a trip i got no warnings. Need advice. is it the coil packs? or what else could it be. i got the jeep used about a month ago, it has 135,000 miles

 

i hate to say it but......your heads are prob cracked or head gaskets.

check your oil and see if it looks like a milk shake...also check your coolant and see if its low.

if ur oil looks like a milkshake.....stop driving it or your gonna toast your bearings and get the heads/gaskets fixed asap.

btw this is a common problem with the 4.7L.

if its not this then i would hook it to a scan tool and see if there are any codes stored. could also be something simple.

 

remove your valve covers and look at the rocker arms, if a rocker arm came out from under the camshaft that will happen .. been there done that ... I was told that a worn valve guide was the problem but I installed a new lifter . seems ok ...