2003 4.3 engine code X, 4x4 with 86K miles. I have 3 of these that I use as delivery vehicles on a rural mail route. I acquired this one about a year & a half ago with 68K miles. Ran good for 6 or 8 months when the oil pressure began to drop to near 0 when I stop. The pressure is near normal when first started and after 10 to 20 miles, when it's warmed up well, the pressure at road speed will be just below mid-scale on the gauge, but when stopped at idle drops to zero or very near it. When this problem began, I changed the oil and didn't see anything unusual about the oil, but the problem persisted so I parked the vehicle & didn't use it until recently when I had some time to tinker with it. I checked the fluids, started it up and drove it for 10 or 12 miles. The vehicle runs great with no unusual noises, but when warmed up good the oil pressure problem shows itself and now the dipstick shows about a quart over full with chocolate milk a.k.a. WATER (radiator is also low on coolant). I pulled the intake manifold and found this.....


Here's my question - does anyone think it's worthwhile to clean it up, replace the gaskets, and try it with fresh undiluted oil, or just go ahead and pull the engine & replace it? I don't know if the coolant would thin the oil enough to cause the loss of pressure or if that's a separate problem. Also when I initially noticed the low pressure, I saw no evidence of coolant in the oil unless it was a small enough amount to not be noticeable.

Any thoughts would be appreciated. I'm leaning toward the replacement option.

Jerry