I know this should more appropriately go on GMTN but I'd rather talk to you guys about it. As many of you know, I recently purchases a spare truck, 1994 GMC Sierra 4x4 with the 5.7V8.
I got a really good deal on it but the guy told me he thought it might need valve seals eventually. He said when you first start it up of a morning it would puff a little white smoke but nothing else.
When I test drove it, the truck was cold, hadn't been cranked in several hrs and didn't smoke at all. I've been driving it as much as possible the past few days to check things out.
I've noticed when you first crank it if it has been sitting overnight it does have a little bit of white smoke . If you sit idling at a stop light it has a decent amount as you pull off. I don't notice it smoking at all while driving even if you romp on it pretty good, it runs good.
I knew it was loud when I got it, but they removed the cat and mufflers. I somehow didn't notice it when I crawled under it to check for leaks etc.
So no cat, no mufflers and it never gets over about 150 degrees.
Oil looks good, coolant looks good, levels are stable.
I'm getting ready to put new exhaust in it and a new Tstat.
Does anyone think the smoke is due to the engine never getting fully warmed up?
I'm thinking that possibly part of it could be it is never warming up and running rich but just wanted to get some ideas from the experts here. It also wouldn't surprise me if it was beginning to show it's age at 208k.
Also on exhaust, I was planning to just do a single exhaust but am debating true duals. I don't figure I would ever need the performance added but I really don't like the connecting pipe running right under the tranny and it would help it breathe.
Any thoughts or on duals? Would it be much of a gain for a hauler? I called one place nearby and the single exhaust will run <$400 and the duals about double that.