Narrow it down

[Daniel911Tahoe]

Hey, so I have a 2011 5.3L Tahoe with 99k miles on it. Oil changes are done on regular basis. A ticking is occurring. It was occurring at idol and then also in gear. Thought it was a lifter issue. So Seafoamed it and put fill synthetic in it. Feel like the sound got worse. Researched it a little more and realized the oil gauge was bouncing around. Level on 40 at Idol, but when accelerating, needle moved to higher pressure. Its odd, as it didnt do that before this ticking fiesco. So thinking oil sensor, bought one but the more I think about it, now I think its the oil pump or that stupid little rubber seal on the oil tube. So I reversed my thinking and changed out the oil again, but now to a thicker oil. The ticking at idol has gone away, but when driven, still ticks when in gear. Ordered the pump and ring. Havent done anything with it yet, because tearing it apart to change these out doesnt sound to appealing, so just asking if I went through diagnosing this right. I got under the truck pre-heavy oil change and the ticking is coming from next to the oil pan. Any advice?

 

[swathdiver]

There ain't no lifters to tick near the oil pan, that's crank bearings and they knock. Ticking could be an exhaust leak though, the manifolds are nearby.

Don't mess with your oil viscosity. Let's say the previous owner used regular oil and changed it every 7-8k miles. There's going to be a lot of gunk and sludge build up. Now you come along and put synthetic in it which breaks all that sludge loose and gets it moving throughout the oiling system. Takes a couple oil changes at least to get all the yuck out, even with seafoam.

Normal hot idle oil pressure is about 25-30 psi and gets higher underway. If its bouncing around, that could be the little screen under the sensor needs cleaning/changing. If you have erratic and low oil pressures that can point to the o-ring and or a prematurely worn pump.

Do you have an LMG or LC9 engine?