Need help- oil burning smoke -Valve seals?

[Zeus]

The story:I changed the head on my car. The previous one had bent the valves, as the timing belt skipped. Well, I got another head I bought here in the classifieds and did the changeover. It was within tolerances so it didn't need resurfacing. The guy claimed it was good before the lower motor went out on him. I tightened the head the way your supposed to, and was very careful with the head gasket. Either way, so I'm all finished and now the car smokes. It is a whitish bluish smoke (oil it seems to me).

My car and other info:'92 eclipse 2.0 non turbo. I didn't bother with changing the valve seals at the time (as I was too lazy to go to the store to get the valve spring compressor). The cylinder walls looked perfect on my car by the way, not a single bit of scoring. The intake had a little burnt stuff on the inside, as due to the intake valves all bending (and not closing all the way) I guess the mixture had been igniting in the intake. Some other clues are that 1) the car doesn't smoke on startup. It takes about 20 seconds or so for the car to start smoking- which is probably as long as it takes for the oil to get to where the problem is. 2) The smoke is not coming from just one cylinder. I cut each cylinder by pulling the injector, and I couldn't see a noticable difference in the amount of smoke by cutting each one cylinder. It's possible I didn't run it long enough to see if the smoke really stopped after cutting each cylinder, but I thought it might be harmful so I didn't cut the injectors for long. The car runs really well despite the smoke, runs super smooth and revs real easy, not really any noticeable performance difficulties. Just the smoke. I must mention the catalytic converter is bad. Before the car blew it's valves, it couldn't pass smog anyways and was diagnosed to be the catalytic converter. But the car didn't smoke at all before it blew the valves, when the cat was bad. I also have had many cars that don't have cat's at all and they don't smoke this bad. Also- I'm sure it's not a vacuum leak or a missed hose as I have one on my twinturbo 300zx right now and I know what they look like (waiting for gasket to come in). I also have one plug I forgot/lost where it is supposed to go into. It's the plug that comes out the bottom side of the throttle body. I can't find where it plugs into the harness. Lastly, the check engine light is not lit.

My question: Do you guys think this is because of bad valve seals? If it were bad valve seals, wouldn't it smoke on startup, because of oil leaking in when it was off?
Could this be caused by the head gaset failure? I thought there was fluid mixture when that happens. I thought that the pressure in the combustion area would prevent any oil from seeping in if it were a bad head gasket.
What about the burnt stuff in the intake? Do you guy think it's causing the smoke? Possibly plugging something? It was pretty gunked up in there. I had tried to clean as much off with a rag, and I don't think the gunk went much higher than where the injectors are, which is at the bottom of the intake (so it probably didn't plug anything).

Sorry about the length of this monster of a post, but I wanted to give as much info. as possible. Thanks for all of your help, Colin.

 

[GTM]

Colin:

I usually quote select parts of a post but you tossed too much out besides the bath water.

You asked about a head gasket. You are incorrect in saying that the pressures would keep the water out (of the cylinders). Yes on compression and ignition but there is the intake stroke when it can occur. It can blow between cylr 2&3 is common on many 4 cylr engines. It can blow into one of the oil drain back passages and you get water in the oil. In some cases it will blow to the outside. It would be unusual for oil to blow any place but the main feed into the head. In any case it would involve only 1 or 2 cylrs and not all. Are the plugs oily? Have you taken a compression test and a leak down test? Yes a very rich running engine can wash oil up from the rings and make blue smoke but it will also make black smoke as well.

More than likely you already know the answer but just don't want to admit it. Valve stem seals!! Sure it could be pistons/rings but you ARE going to do that compression test, right??

Now you are stuck doing the seals the hard way. I do hope you checked the valve stems and guides for wear.

Cheers,
GTM

 

[Defiant]

Eh, it's not _that_ tough a job, and aren't DSMs fairly easy on guides anyway?

 

[GTM]

Originally posted by Defiant
Eh, it's not _that_ tough a job, and aren't DSMs fairly easy on guides anyway?

Hey there, where ya been.

You are right on both counts. The guides look like a high grade phosphor bronze with some other alloy I don't recognize.

It's a judgment call he made on the seals that bit him in the backside. It just would have been so easy to have popped them off while it was apart. It's easy to say yet we all have been there with something or other AND more that once.

Knowing that a 14mm(?) open end box just fits the guide and a strategic placed block of wood for a fulcrum they pop right up, I used a 14mm deep well socket and shot filled plastic hammer. The deep well helps guide your eye for a straight shot... no muss no fuss.

My $5 valve sping compressor (I know, I know where are the picts) and some string or 1/2 line to fill the cylr would make short work of the intakes. It's arguable on the exhaust for they are under pressure most of the time, still it wouldn't hurt my feelings if he went ahead and changed them. He's got the thing setup and it's the easier set to get to.

Can you think of anything else that could contaminate all cylrs from his report?

Cheers,
GTM