Greetings all, I stumbled on this website by accident and I am glad I did. It has a ton of information on oil for a DIYer like me. Anyhow, I have a strange issue I would like to bring before everyone and gather opinions and what not. Car: 1996 Lincoln Town Car, 4.6L Modular SOHC V8 2v Mileage: 104,400 I recently acquired this vehicle. First thing I always do is fluid and filter changes with a new vehicle. First week I drained the old oil out (I was told it was 10W30) and added a fresh change of Castrol GTX 5W30 dino oil (the owners manual states 5W30 motor oil) and a fresh filter. About a week or two after I changed the oil I dropped the transmission pan and drained the fluid and added a new filter. A couple days after that I noticed an audible ticking sound that was not there previously. I pulled out the stethoscope and began trying to source the sound. I could not find the sound with the scope. The injectors were pulsing, but not making this ticking sound. The intake manifold gasket is ok because it ticks at idle, warm or cold, and I was told if the intake gasket is bad it will stop ticking once warmed. I finally took it to my indy mechanic, and he diagnosed the ticking as rocker or lifter noise (cant remember which one he said, but I know it was rocker or lifter). However I could not hear the noise through the valve cover with the scope, but he still said it was lifter/rocker noise. I told him that I recently switched from 10W30 to 5W30 and he told me to switch back to using 10W30. However from everything I have read, using 10W30 in the Ford Modular 4.6 is a bad idea because of small oil passages and tighter tolerances in the engine. So, my plan is to seafoam the engine this weekend, and maybe switch to a different type of oil. Right now im using dino. Do you guys think that a switch to a quality synthetic 5W30 would help? For those who know the Ford 4.6, would switching back to 10W30 be a good idea? Sorry for rambling on. I don't think the ticking is a big deal, but it drives me crazy. Thanks for reading.