Hey guys, heres the deal. I have an 88 iroc lb9 engine. I have no Cat. converter, just 3inch pipe all the way back to the muffler and then 2 inch tale pipes. Right when I start the car I get a puff of smoke, not sure of the color, grey or light blue. What could this be? could this be oil leak, or tranmission fluid? Thanks :lala:

 

You probably get a small puff when you shift gears while racing as well. I would imagine other than the first time you start the car up in the morning you get the puff but not after that.....

Most people will tell you the valve guides are worn and you need a valve job, I'd say change the valve seals first. You can do it with the heads on the car with the correct tools and an air compressor.....

Your engine will probably go another 50K before it starts the smoke thing again......

 

Valve Seals?

<Edit> I asked it as a question to him as to weather or not he considered, not questioning anything with the above statement. I had an 88 IROC that had the notorious puff of smoke problem and had the warranty take care of the car when I first bought it. Sorry for the confusion.

 

I have come to the conclusion that it is white smoke that puffs out at start up. After start up I can rev the hell out of it and get no smoke. I am not sure if it smokes when changing gears, while running it hard. Does this still sound like valve seals? How hard is this to change? How much? And what are the required tools? Thanks

 

If your leaving the heads on, you need to make sure you have an air compressor, valve spring compressor that you use while the heads are on, the airline with the fitting to go into the sparkplug hole (this will hold the valve up while you take the spring off and replace the seal). Small rubber mallet to tap the retainers before you compress the spring to loosen the retainers.

 

Yes, I have had two (1985) cars that have done the smoke thing on starup first thing in the morning. They never smoked again all day unless I was racing and I would get a small puff when I upshifted (automatic) at 5000RPM.... Changing the valve seals took care of the problem. Both had around 50K on them when I did it......

 

White smoke? How is your coolant level over a period of time? It may be a small intake manifold leak, I know alot of the TPI cars run into this, but I'm not sure about the lb9's.

 

sounds like the valve guide seals. they are cheap, you will also need valve cover gaskets. i fixed mine for 30 bucks. the factory seals are machined to fit. the aftermarket ones are what they call umbrella style. they dont require machine work to fit properly.

the reason they will smoke is because when you shut the engine off oil will drip onto the seals and then when you start it, the oil burns, causing the smoke at startup.

 

My 88IROC 305 did the exact same thing. Smoked on startup but no smoke when running. Changed all the valve seals and no more smoke. It was a tough job since I could only get to the tough plugs from below. But with a good manual to explain it, a good COOL day and you can do it with the tools everyone above says. Oh yeah, make sure ALL the rockers are adjusted. I buttoned everything back up, started it up, and tic tic tic tic tic, etc.

 

Take the heads off, take them in the machine shop of your preference who knows what they are doing, tell him to just go over them, and u will be in some good shape. Should cost you around $160 out the door.

 

Coolant looks good. The car puffs smoke at every start up, if it sits longer than a few minutes. After that nothing. I had my wife follow me and I floored it, she said she thought she saw a little white smoke but would not bet on it.I have the Chilton Manual, but no info on valve seals. Any suggestions? Also a mechanic told me I may need a new oil pan due to a"piggy back plug?" I have not a clue what this is. Is changing an oil pan tough? I do appreciate all the help. fist time restoring a car and its tough, but a blast!!

After thought....Taking off heads and having them machined does what exactley?

 

dude i dont know if you want to take your heads off or not. i personally wouldnt. but it you dont have accses to an air compressor then you have no choice but to do so. if you do take them off all you will need is a spring compressor which you can rent from auto zone for a desposit which you will get back when you return the tool.

remove the rockers, put your compressor over the stud and put the nut on, compress the springs, and take out the old valve guides. all it is, is a little rubber washer lookin thing. then put the new umbrella seals on. uncompress the springs and put you're nut back on with the rocker arm. this is a very very easy fix. and if you do it yourself it will only cost you 30 bucks with out takin the heads off, but if you do take them off you will need a pair of head gaskets and an intake gasket.

 

Taking the heads off just to clean them up and check the seats and guides. Basically completely reconditioned heads.

It's likely (.02 from your description) that it is the valve seals. Especially if it sits for more the 4-8 hours before it will puff smoke again.

Tony

 

GM has a bulletin about this issue. Many were taken care of under warranty since it happened with as little a 20k on the engine. They recommend part # 12511890, it is a positive umbrella seal with a "viton" insert. Can do it on the car, no need to yank the heads.

 

An air compressor can be rented. A remote starter switch is needed to rotate the engine as you go from one cylinder to the other unless you have a helper. Other then the spring compressor, the only other thing needed is fittings to connect the compressed air to the spark plug hole. I used an adapter I bought from a part store along with some compression fittings. There may be other adapters available

 

here is what i did. did a search on here on valve seals. And i found a great way to do them without a compressor. Take some rope and stuff into the cylinder that will hold the valve up while changing the seals. Seals are easy to change, the hardest part is getting the spring retainers off, wack em good with a hammer and a socket on top of spring first to loosen em up. You need a spring compressor tools for the valve spring. Get the stud type i busted my butt with the screw type with the wings that grab on the side of the spring. The stud type mounts to the rocker stud and then you can press the spring down, no flying parts. oh and you ned a small magnet for the retainers make the job easier. i used a magnet that was on a screw starter that i had was small and did the trick.

Good Luck Jeff