2000 GMC Sierra 5.3 4x4 with 190K; solid truck; no oil burn; no leaks; tediously maintained. About 50K ago, tech talks me into full synthetic Mobil 1. I have synthetic in 1-ton diesel and 07 Tahoe, so I go for it. All is well....I think....but of late, at 5-7K, I change oil and it's "muddy". Like dark milk chocolate, with some lumps at bottom of stream...just a few, gelatin-like. Oil is not true milky like water in it, though there is a small amount of condensation under oil cap; tech says that's normal. ?? Could it be that the synth oil is cleaning crap outta there? It's not overheating and there's no oil in coolant like a head issue. ?? It has always "used" about a pint of coolant every 3K. Thoughts? Thank you. -Bryant

I have this Chevy truck with the utility box instead of pickup bed on the back. 1 of the brake lights is inoperative so I assume the bulb is burnt out. I've removed the lens housing it, and it seems to be a sealed unit. I can't believe I have to buy the whole assembly and would like to know how to replace the bulb in it. Does anyone know of a website that might have a diagram of the tail lights on microfiche? Thanks for any suggestions!