Small Puff Of Smoke On Startup - Once In A While.

[pspaude]

I have a 1999 GS400 with 55k miles on it. Not driven hard. On occasion I will get a puff of smoke on startup. It does not smell exactly like regular crankcase oil. It only does once in awhile for about 1 or 2 seconds and then it is done. I have been told it is the valve seals from one person, but that seems early. I have also heard that there was a problem with power steering fluid being sucked back into the engine via a leaky vacuum valve from the power steering unit to the engine. Does anyone have any ideas on this, and if so, what is the remedy?

Thanks,

[Kevs98gs4]

valve stem seals......toyota is known for crappy ones.....about the only thing they can't seem to get right. it's not always about mileage with those it's time!

[SRK]

My 98 GS400 does it occasionally, as does my 92LS. It is the result in both cases from starting the engine briefly (say a minute or less) to move the car in the driveway and then shutting it off. It's caused by the cold start fuel enrichment and it leaves fuel in the cylinders unburned and dilutes the oil on the valves and cylinder walls. On the next start the excess fuel, and the diluted oil is burned causing visible smoke briefly. It can be very bad on my LS if it is moved twice without a warmup - enough that the engine misfires and shakes badly. Creeped me out the first time it happened.

I don't know if you can relate the oil burning on your engine to previous short duration cold starts, but maybe that's all it is.

In my experience Toyota valve seals are about as good as everything else they make. Mitsubishi seals are definitely crappy, as is everything else about those cars.

[smooth1]

I don't think it's the valve seals. While I agree that they are one of the nuisances of the toyo motors, typically in the past when I see this problem, it's more of a regular issue, and not just a once in while puff of smoke.

I think you may need to clean your intake and engine breather tube. The breather tube can pull oil from the block as it relieves the pressure from the crank case, and it may be getting in the intake and that is what I think your seeing burn when you first start the engine.

So, on the intake tube, you should see a rubber hose that connects to it. Pull that hose off and wipe it with your finger. It should have some residue on it, but if you notice that you also wipe oil from it, then take the hose completely off, and clean it out with some parts cleaner, or wd 40. Just stick the red straw nozzle in it and see if you can blast it all out of there. Then pull the intake tube off and clean that out. reassemble it and give it a day or 2 and see if that clears up the smoke issue.

[pspaude]

I don't think it's the valve seals. While I agree that they are one of the nuisances of the toyo motors, typically in the past when I see this problem, it's more of a regular issue, and not just a once in while puff of smoke.

I think you may need to clean your intake and engine breather tube. The breather tube can pull oil from the block as it relieves the pressure from the crank case, and it may be getting in the intake and that is what I think your seeing burn when you first start the engine.

So, on the intake tube, you should see a rubber hose that connects to it. Pull that hose off and wipe it with your finger. It should have some residue on it, but if you notice that you also wipe oil from it, then take the hose completely off, and clean it out with some parts cleaner, or wd 40. Just stick the red straw nozzle in it and see if you can blast it all out of there. Then pull the intake tube off and clean that out. reassemble it and give it a day or 2 and see if that clears up the smoke issue.

Thanks for the reply, I will give this a try and see if that is the culprit.