Start up smoke on Firebird

Status
Not open for further replies.
Short of going with a really thick oil, it would seem that your going to have smoke regardless until the engine heats up based on the extra clearence.
 
I understand that forged piston's expand much more than cast, but to take an "extra" .005 on top of what the piston manufacture recommends for clearence won't work very well, especially when cold. Loss of compression, oil consumption and premature ring and piston wear will happen if this is true.
 
I'm sorry, I misunderstood my machinest friend. I just got off the phone with him and he told me that on the TRW piston that I am running, TRW recommended a minimum of .005 clearance NOT an extra .005 clearance. He said mine has a total of .005 clearance. He said if he had done that my motor would be rattling like ****.

Compression has been checked on all cylinders and all is good. The motor runs great. It just did not smoke like this with the dino oil.
 
quote:

Originally posted by GoldenRod:
BlazerLT,

This has happened many times before by someone switching from DINO to synthetic on this board. RP and Mobil 1 have done this to more than a few BITOG members.

When the balance between Ester and PAO is not just right for a given seal, causing the seal either to expand or shrink, seal failure is prevalent.


That is not the oil causing the failure, the seal was already worn and the oil did its job cleaning out the sludge plugging the bad seal.

This is not the fault of the oil, the damage was already there. All the oil did was uncover it.
 
quote:

Originally posted by James408:
Ok, first off, I don't think RP has detroyed my seals because it was only in my car for one day.

As far as the extra clearance, my machinest, who is a friend of mine told me 5 thousands. The extra clearance is recommended for my forged pistons. When a forged piston heats up, it expands.

To play it safe, I believe I'm going to go back to the Havoline 20w50 SL.

Anybody have a paint strainer and need some slightly used Royal Purple. I'll make you a good deal. (ha, ha)


With a little patience, the oil might actually re-swell the seal within a couple 1000 miles.

What color is the smoke?
 
Hi, Blazer. My motor is about five years old and has less than 5000 miles on it. New valves and seals where installed in the heads at the time of rebuild. Wouldn't say the seals are worn. Maybe they are. I don't know. I will probably give the rp oil a chance but it would probably take me a couple of years to put 2000 miles on it. On start up with the RP, it is light blue. After it warms up the smoke is white from my tires.
 
Have others experienced this when switching from conventional to synthetic? It seems like I read somewhere where someone converted to synthetic and it smoke a little at first but eventially stopped after some miles on it.
 
My 97 Chevy Sub had 120,000 miles when switching to Synergyn LTS 3/30. It smoked like a freight train for a couple days then stopped. No oil consumption issues at all now. This is why you might give it a chance.
cheers.gif
 
Try running the RP for a week and see if your smoke gets better. It may just be cleaning deposits off. If it has not gotten better in a week you can always switch back to the Havoline you were running prior to. And post results as I am curious to see if it does indeed slow the smoke on start up.
cheers.gif
 
James408,

Do you have a PCV system installed?

Could be the oil coming through the PCV system that is burning.

Even though the seals are 5 years old, it looks like they sit quite a bit and dried out.

Shouldn't be much to swap them out.
 
James408,

You're going to have to pull the valve covers and replace the valve seals. After that, go to a mineral based oil. Not all seals are able to handle synthetic oils. I just hope that your other engine seals are alright. BTW, 20W-50 is too thick for a motor with just 5000 miles on it. Go with 10W-40.

GR
 
quote:

Originally posted by GoldenRod:
James408,

You're going to have to pull the valve covers and replace the valve seals. After that, go to a mineral based oil. Not all seals are able to handle synthetic oils. I just hope that your other engine seals are alright. BTW, 20W-50 is too thick for a motor with just 5000 miles on it. Go with 10W-40.

GR


All valve seals can handle synthetic oil.
 
Oh really?.......

You show me a listing for a valve seal for any engine that states that synthetic will "eat them away and destroy them."

Anyone thinking that a synthetic oil will degrade seals should stop getting their information from the 70s.

The "synthetic shrinks seals" myth has been killed for 2 or more decades.
 
James408 don't sweet it. If your only getting a little blue smoke on a cold start don't worry about it. Take it from someone who owns three forged piston motors. It not that unusual for a Forged piston motor to do this a minor amount until the pistons get warm and expand better. Ring seal is not optimum on a cold start due to piston rock at TDC. Cold start piston rock is a byproduct of the required bore clearance for forged pistons. If it was doing it with the motor warmed up it would be a different story.
 
quote:

Originally posted by Hirev:
James408 don't sweet it. If your only getting a little blue smoke on a cold start don't worry about it. Take it from someone who owns three forged piston motors. It not that unusual for a Forged piston motor to do this a minor amount until the pistons get warm and expand better. Ring seal is not optimum on a cold start due to piston rock at TDC. Cold start piston rock is a byproduct of the required bore clearance for forged pistons. If it was doing it with the motor warmed up it would be a different story.

You have a very good point there.
cheers.gif
 
quote:

Originally posted by BlazerLT:
"eat them away and destroy them."

BlazerLT, who are you quoting? Those are not my words.
confused.gif


Anyway, you have your opinion and I have mine. It's as simple as that. The End.
cool.gif
 
Sorry, I have FACT, you have opinion.

Even the guy that started this thread is dismissing your "the Royal purple" destroyed the valve seals claim.
 
Hey guys, don't argue over me. Thank you for your interest in my 400. The motor does not smoke once warmed up with the synthetic. Its only on start up. I'm just not use to this because the Havoline does not smoke on start up.

I don't think I have to replace my seals either. What Hi Rev is saying makes since. It going to be a week are so before I can run the Bird again because I have to pull my transmission due to fluid coming out the front seal.

Golden Rod, I am running 20w50 in my motor because that is what I prefer. I'm kinda the black sheep of this forum who prefers a heavier oil. Pontiac's have large bearing surfaces. I've tried 20w50 and the 15w40 but my motor runs better and smoother with the 20w50. I live in south Texas and my car is rarely driven in cold weather. Besides aren't 10w40's known for breaking down?
 
Ok, we'll just agree to disagree on oil weight. I've opened that can of worms on this site before and it wasn't pretty.
 
Status
Not open for further replies.
Back
Top Bottom