91 Olds Bravada bluish smoke at start

[wbchang]

My 1991 Olds Bravada (150K miles, TBI) spits out bluish smoke when first start after sitting for a few hours, then no smoke for 2 - 3 seconds before white smoke comes out. I think white smoke is normal in the cold days, is there anything I have to worry about about the bluish smoke? Has been like that for the past few yeras, truck runs OK, found this forum recently, any help is appreciated.

[TonyMazz]

Prabably, a small amount of oil is seaping down from valve guides on one or more of the cylinders during the heat soak period during shut down.

What oil are you using ? How often do you change it ? Have you owned this from new ? The motor IS 14 years old now.....probably gonna burn alittle, drip alittle, smoke alittle....

Is it a 4.3L motor ?

[wbchang]

Using Valvoline MaxLife 10W30, changed oil & filter regularly about 5000 mi, had this truck for about 6 years, it is a 4.3L TBI 4WD.

Previous owner had maintenance serviced by dealer till about 90k miles when I bought it. but I fixed it only when broken, except change oil & filter. Start thinking of doing maintenance. Any suggestions on what to do fo rthe long-due maintenance. Truck is still running OK without problems, gas mileage about 15 - 17 in city, 23 on highways.

[mike2004tct]

Sounds quite normal for the year and mileage. By this age, you can almost expect to "fill it with oil and check the gas" at normal fill-up intervals.

[BlazerLT]

Originally Posted by wbchang

My 1991 Olds Bravada (150K miles, TBI) spits out bluish smoke when first start after sitting for a few hours, then no smoke for 2 - 3 seconds before white smoke comes out. I think white smoke is normal in the cold days, is there anything I have to worry about about the bluish smoke? Has been like that for the past few yeras, truck runs OK, found this forum recently, any help is appreciated.

Worn valve guides and valve seal more than likely.

You can pick up used heads from a junk yard and install them for your year and the problem will go away and be perfect.

Does the white smoke go away after a while?

[wbchang]

Originally Posted by BlazerLT

Worn valve guides and valve seal more than likely.

You can pick up used heads from a junk yard and install them for your year and the problem will go away and be perfect.

Does the white smoke go away after a while?

The white smoke goes away in a little while.

Is that difficult to replace the head? How to tell the junk yard what I need? just "heads"? about how much?

[BlazerLT]

Not too difficult really if you have the proper tools and a torque wrench.

Ask for heads off of a 91 TBI 4.3L.

I can't tell you the price, I presonally don't know.

Best to pick up a haynes or chilton's repair manual to help in the repair. You will need to replace the head gaskets as well.

[molehole]

Why put different heads on it. I wouldn't mess with something that runs good. Just check your oil often and keep an eye on fluids. It is a lot less aggravation then replacing a bunch of stuff on a 14 year old SUV. Best bet is to maintain it until the thing finally runs no more. I would change my oil a little more often if I were you but thats just me. As for maintanence just keep up the changing of fluids and tune ups. If you go and start fixing things that aren't really a problem, then stuff ends up going wrong where you didn't have problems before. Good Luck

[TonyMazz]

You read my mind exactly...I would not rip down a motor cause a puff of blue smoke......

Keep it rolling........

[BlazerLT]

Originally Posted by molehole

Why put different heads on it. I wouldn't mess with something that runs good. Just check your oil often and keep an eye on fluids. It is a lot less aggravation then replacing a bunch of stuff on a 14 year old SUV. Best bet is to maintain it until the thing finally runs no more. I would change my oil a little more often if I were you but thats just me. As for maintanence just keep up the changing of fluids and tune ups. If you go and start fixing things that aren't really a problem, then stuff ends up going wrong where you didn't have problems before. Good Luck

Because oil leaking into the combustion chamber nothing to just disregard.

For a small investment and time, he could have no burning oil, reduced oil consumption, less plug fouling, cleaner running engine.

Heads are not that huge to replace and cannot be taken as "tearing down the engine."

[TonyMazz]

Originally Posted by BlazerLT

Because oil leaking into the combustion chamber nothing to just disregard.

For a small investment and time, he could have no burning oil, reduced oil consumption, less plug fouling, cleaner running engine.

Heads are not that huge to replace and cannot be taken as "tearing down the engine."

Geez you make it seem like he's dumping a quart of oil through there in a few minutes....he just said a "puff" of blue smoke....you are describing more than that...

Heads are not that huge to replace ??? valve lash, sensors, manifolds, rusty/frozen studs...not to mention gaskets, etc....I'd say it's easy to "armchair" it from our forum, but it IS a big deal....

Disconnect the battery negative cable. Refer to Battery Replacement in Starting and Charging.
Drain the engine coolant. Refer to Draining and Filling Cooling System in Cooling System.
Remove the air cleaner outlet duct from the throttle body. Refer to Air Cleaner Outlet Duct Replacement in Powertrain Management.
Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Powertrain Management.
Remove the engine cooling fan assembly. Refer to Fan Clutch Replacement in Cooling System. Important: Do not evacuate the A/C system. The A/C pipes can remain on the compressor.
Remove the air conditioning compressor, if equipped, and move aside. Refer to Compressor Replacement in Heating and Air Conditioning.
Remove the AIR pipe bracket and nut, if equipped from the power steering pump rear bracket stud.
Remove the nuts holding the power steering pump rear bracket to the engine.

The power steering pump can remain on the power steering pump mounting bracket. The power steering pump hoses can remain attached to the power steering pump.



Remove the power steering pump mounting bracket and secure out of the way. Refer to Accessory Mounting Brackets Replacement (PS Pump Mounting Bracket).
Remove the power steering pump mounting bracket stud from the cylinder head.
Remove the intake manifold. Refer to Intake Manifold Replacement (Lower).
Remove the exhaust manifold. Refer to Exhaust Manifold Replacement (Left 4.3L).
Remove the spark plug wire harness and the support.

Remove the ground wires at the rear of the cylinder head.
Remove the fuel line bracket bolt at the rear of the cylinder head.
Remove the valve pushrods. Refer to Valve Rocker Arm and Push Rod Replacement.

Remove the cylinder head bolts.
Remove the cylinder head.
Clean all surfaces. Refer to Cylinder Head Clean and Inspect.

Labor with all the tools is about 13.7 hours if a dealer does it on both sides....

Not a big deal !? Your'e nuts !!!

[blazes9395]

You don't need to replace your heads at all. Its the valve guide seals. The valve seals harden as they get older letting some oil get past them. The valve guide seals need to be replaced. You can get the valve seal kit from the dealer, its around $50.00. It contains the valve seals, retainer o-ring seals, and the plastic umbrellas for the exhaust valves. This can be done with the heads in place on the engine. I have owned four 4.3L litre engines, all have needed this done. After I changed the seals, I have never had the blue smoke at start-up again. You don't need to replace your heads, just change the seals at the guides - it will solve the problem.

[wbchang]

Thank you all for the suggestions, I think replacing the head is way beyond what I want to do, and yes, it is just a "puff" of light blue smoke, that is all. So guess I will keep driving until it dies, thanks again.

[BlazerLT]

Or just replace the valve guides, that is pretty cheap.