Ok, maybe my good deal wasnt' so good after all. The beast; 91 Blazer S-10, 2 door 4.3 (4x4). It runs good, but after running a tank of gas thru it, I noticed it had blue smoke this morning after I started it up the first time. It's been sitting for a week. It only puffs blue after I rev it up and let off on the gas. So, is that bad intake or exhaust valves? jb
Blue Smoke....Waaaa
Jul 01, 2004
9 Replies
Doing just what mine did after 150K miles..If I'm right, the smoke is caused by the burning of oil that has seeped by the valve guides while it's sitting
Common problem that can be fixed by replacing your valve seals.
Big Chris
.......guides and seals
-- Mad Dog
You don't have to pull the heads to do this. Valve covers and a spring compression tool IIRC will do the trick for you. I do recommend taking the hood off if you choose to go this route though, as banging your head on the roof while doing the rear sets isn't all that fun. Also by doing them in vehicle, you save yourself from having to deal with extra gaskets and such. But as you mention, if you go the route of pulling them, you can refresh the whole top end. Depends on your needs, time, skill, and money :-)
Big Chris
I"d start with just the valve seals first. You can do this for a lot less money then pulling the heads. You can also check the guides for excessive play while you are doing the valve seals (you must be careful at this point, as you don't want to drop the valve down inside the engine). Then if you happen to find a worn valve guide, you can make your decision as to whether you want to pull the heads. There is a good chance though, that new valve seals will solve most if not all of your problem.
Ian
you can change the seals w/o pulling the heads by using a adapter from a universal compression tester and hooking it up to a compressed air source, this will pressurize the cylinder and hold the valves up. you can then use a spring compressor to compress the springs and remove the keepers,retainer,spring and finally access the guide seal. if ya wanna do it right then you should pull the heads and have bronze guides installed and cut them for neoprene seals. if the motor only smokes at start-up then you don't need oil control rings, but if it smokes during accelleration then you may wanna drop the pan and knock the pistons out for a re-ring if there is no ridge at the top of the cylinder indicating a severely worn and out of round bore. cylinders become oval shaped with wear and the rings conform to this shape with wear so re-ringing a motor in this condition would most assuredly be a waste of money as the rings would never seat correctly resulting in major compression loss past the top rings and excessive oil consumption. good luck friend
-- Mad Dog
In my case new stem seals would have been some help, but I ended up relacing the entire motor. Got tired of people walking up and telling me that I needed to either add soe oil or buy another car..... (had a piston slappin that you could hear from a block away at low speeds)
You'll play hell getting the oil pan off the motor with the engine in the vehicle if it's 4X4.
It can be done-- but for al the disassembly, it's almost easier to take the damn engine out.
Then, if you're like me, and you have the money, pay Advanced for a reman unit and replace the whole friggin' engine. 8)
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