I recently just bought this truck, a '94 Ford Ranger V6 3.0L, 5 Speed with 138,000 miles.
I took it to a relative's house a little over a month ago and my check oil light was on so I just went for a normal service (didn't have a service sticker on when I bought it). I had them check it for oil leaks and they changed the oil plug and said that I had some leaking around the motor that wasn't that bad.
So I left it alone and just stuck with changing the plug. Around this time I started noticing that when I was driving around in the city where I have to start and stop a lot that it was blowing some white smoke while sitting and then when I would take off through first and second gear.
A month later my oil light came on that my oil was low again, so I changed it and went and replaced my valve seals also as they showed signs of needing replacing. As soon as I had it back together, I took it down the road and brought it back. When I got out and let it idle for a few minutes, it seemed to be blowing quite a bit of the thin white smoke.
The next day I found out that my water pump was leaking, so I started taking it back apart to replace it.
I'm concerned that the white smoke means I have a blown head gasket, but the truck NEVER heats up past the normal range on the temperature gauge. Does anyone have any thoughts on what it could be? Is it most likely the head gasket?