Hello. Glad ya'll are around. I have a need for some input. First of all, I do have a reasonable amount of knowledge with automotive repair.

My 1991 Pontiac Firebird has a nasty white exhaust that blasts out of tail pipe when first started; After the wretched pinging and nocking ( coolant water not wanting to compress in the cylinder ?) I have to force it to idle until it gets warm. The white smoke continues to billow from exhaust pipe even when driving and after warm up. It smells horrible. After warm up the car idles and sounds real good. With its white smoke of course. There is no overheating and the oil pressure is between 35 and 45 psig all day FWIW. Coolant is "mysteriously" vanishing. Oil shows no presence of water. Car has overheated in past. I have since replaced intake plenum gasket.

After extensive research, My question is , do I really have a head gasket failure? Cracked head? Block?
should I fool with pulling the top end of the motor apart? I have had this car for 10 years and it is very dear to me. I have done only the best for it.

Thank you for reading.

 

could be a cracked head if overheat incident was severe enough to boil heads dry of coolant-remove and check spark plugs for any that look suspect.Leakey head gasket also possible.

 

Thank you. I will check as soon as time permits. I do remember that as a kid, i didn't know of the lubrication capabilities that antifreeze has for the water pump.
One day the car got hot while running straight water in summer (because of overheating problems) and the water pump seized entirely causing my belt to smoke in half. I guess it got 'damn' hot. However , I would immediately shut it down to cool off every time when i noticed it overheating. I guess a gasket will fail before a head in most common cases of course.

 

Your car has either a head gasket leak, cracked head, or cracked block. Really no other ways for coolant to get into the chambers if its not coming from the intake.

Check the oil for a milk shake like texture. If its a milk shake, then you have coolant in the oil and you need to address it STAT as its causing excessive wear and will cause early failure of the bearings.

For the smoky exhaust? No solution, you have to pull the head to look at it.

 

or intake gasket failure which is a common issue with the vortec gaskets. I would inspect the intake gaskets carefully when removed, especially between the water passage and the front two cylinders.

 

Definitely water being burnt there, just need to figure out where it's coming form. Headgasket being the best case scenario.

 

this video might be helpful?

 

Well, I finally pulled one of the heads. The gaskets look as if they were cooked in an oven. I noticed cylinder number 4 had a light rust spot in the cylinder wall. It wouldn't rub off with my finger so there's an indication I guess. No pitting though. I also noticed that there was no ridge (cylinder wear) at the top of my first bank of cylinders. I've learned that this is a good indication. No cross hatching is visible though. I guess tomorrow I'll pull the other head. My fingers are crossed.