[sanitarium16]

07 Jeep Grand cherokee 4.7L. When i start the car i can hear knocking from what sounds like the bottom of the engine. Its not the fuel injectors those are like a ticking. I know the 4.7 has a knock sensor but it isnt giving a CEL. When the engine warms up i can still hear it but it comes and goes. Im using Mobil 1 5w30 with an AC Delco oil filter. I was using 5w20 and a jeep oil filter and i was still getting it so i thought switching to a thicker oil/different oil filter would help but its still doing it. I have also run amsoil performance improver additive/fuel injector cleaner but that didnt help either. any ideas?

[JeepStreet]

Using right fuel? Octane rating should be in your users manual. Sometimes poor fuel or a lessor than required octane can have an effect on your engine.

WHens the last time you took it on a road trip? Vehicles running at their ideal operating temperature tend to burn off more carbon deposites thus causing a happier engine.

Does this noise you hear from the lower end increase with acceleration? Or mainly at startup/Idle?

[sanitarium16]

Im using the right octane fuel. I have tried switching gas stations and i still get it. The noise is just at idle. I am using the stock tuning for my vehicle right now. It happened before i added exhaust/intake as well. It even does it with the superchips tune.

[colinzj]

Maybe it's the EGR?

[Acidcold]

I get the same sound but mine is more towards the top i think, might be my lifters..

[rhusak]

Guy's..
If the vehicle is still under warranty get it in and let them listen to it..
The knock sensor you mention is there but it is not for that pourpose.. It adjusts timing and is listening for Spark Knock..
Any noise like the one you are describing does not belong there..
Ron