Hello everyone i have a 2010 Jeep Grand cherokee and while driving at 50 to 70 the engine has a mild stumble. Its not constant but every few minutes. You can feel it, it feels like your going over minor rumble strips. And you can see it in the tach, it will loose 100 to 200 rpms when it misses. I have checked the following...compression 185 to 190, checked coils all good replaced anyway, checked plug wires all good, plugs all good and the same color, checked fuel injector resistence 12.9, fuel injector flow with a fuel pressure gauge and pulser, all the same psi. fuel pressure at the gauge was 55 if i remember correctly. Replaced cam and crank sensor just because they were inexspensive. I have pretty much exhausted everything I can think of to check, I dont know maybe i'm missing something. Any help or ideas would be huge, Hate like hell to take it somewhere as I usually do my own repairs. Thanks Guys

 

I hope those replacement cam and crank sensors were OEM. Using aftermarket is a crap-shoot.

Did you run the codes yet? Hook 'er up, man! It may be logging random misfires in the 2000-2500 RPM range. This is only an opinion but any number of things can cause that. Believe it or not, oil condition and flow can cause this kind of elusive performance hiccup issue.

 

No codes, no check engine light and yes they were oem. The oil is changed every 3000 miles. The vehicle has been doing this for about a year, and has pretty much stayed the same. Could this be a driveline issue???

 

Is this the 4.7 Gen II engine with the 16 spark plugs? If so, there are 2 different types of plugs that must be used or pre-ignition will result. One type for intake and one for exhaust. If it's the 5.7 VVT with the MDS system, you're on your own.

Check out wkjeeps.com

 

sorry i forgot the engine size ...3.7, I guess i'll try the throttle body cleaning and maybe the old seafoam through the brake booster vacuum line and see what happens.