Smoke @ startup

Bichn69

Member
Anytime I start up it has a puff of smoke and if I'm going about 40 and floor it. It accels and then makes a clicking sound and a cloud of smoke rolls out the exhaust. Valves sticking?? Usually runs strong and has 104,000 its a 92 Ty. Thanks
 

dgoodhue

BuSTeD 4.3
Re: Smoke @ startup

The puff at start up is valve seals, the clicking/puff at 40 mph is a different problem.
 

ircwet

New member
Re: Smoke @ startup

What breaks down value seals ? Ex I get a puff of smoke at 54,000 and others dont see it at 100,000...My astro 4.3 is at 180,000 and no smoke...
 

dgoodhue

BuSTeD 4.3
Re: Smoke @ startup

I think a truck that sits has more problems with valve seals. Mine were puffing away at 42K mile when I bought my truck.
 

Bichn69

Member
Re: Smoke @ startup

I talked to a mechanic about replacing the valve seals and he told me that that on these motors there's more problems with the rings and that it probably wasn't the seals. Was he blowin smoke up my $#%^. This last weekend I ran some seafoam in the fuel, crank, and brake boost vac line and the clicking noise seems to be happening more often than before though the smoke is white now and alot less than before.(before it was black and a big cloud)
 

NecroWolf

lost marbles member
Re: Smoke @ startup

gmc's just have a general history of vavle seals going bad. i've seen trucks w/ under 10k puff smoke and i've seen them w/ 180k not puff smoke.
 

Don W.

Stab it and steer it
Re: Smoke @ startup

Mine has puffed on startup since I got it 3 years ago with 56k on it. Actual oil consumption is Nil. I don't worry about it. The other prob is more important IMO. Does the noise and smoke occur while you're accelerating or when you let up on it after accelerating?
 

Mtn Z

Donating Member
Re: Smoke @ startup

Mine smokes on startup and I just did my valve seals. Looks like I need valve guides. The previous owner didn't drive it ever though so that further fortifies the belief that trucks that sat smoke more on startup.
 

Mtn Z

Donating Member
Re: Smoke @ startup

I'm fairly certain we did. Another member and I did it and it went pretty smoothly and didn't see any of the o-rings get caught up. I mean, I guess there is a possibility that we may have done one or two wrong, but at this point, I don't feel like pulling it all back apart again.
 

dogboy

uk typhoon
Re: Smoke @ startup

don't know what seafoam is to be able to tell you why it changes smoke colour but black smoke if unburnt fuel......could it be the clicking is knock due to over fueling?
 

werbicki

<User Title Goes Here>
Re: Smoke @ startup

Any chance it has to do with the turbo? I notice that if I start my truck, move it and shut it down quickly that the next start it smokes. But if I leave it running and shut it down warm the next time I have no smoke problems.

Paul
 

dogboy

uk typhoon
Re: Smoke @ startup

what colour smoke then? could be choke/fast idle system not getting to switch off before having to do it aga, also best way to flood an engine
 

odium

1BADGMC
Re: Smoke @ startup

Does it make the click when you normally go from a stop sometimes? If so, it is a backfire you can hear through the intake plenum and you need to change your plugs.
 

Bichn69

Member
Re: Smoke @ startup

I have bought new plugs, wires, cap, and rotor. When i get them installed i'll update you guys. Thanks for all the replies.
 
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