josephjah

Hello everyone,

It's been a little while since I last posted, but I've got a question maybe you can help me with.

It's winter where I live and thus starting the car in the cold is a bit harsh, I've noticed that when I start my car I get a rather noticeably large puff of blue/white smoke (which I assume is oil burning off of something). This only lasts for about 1-2 seconds, and then it's smooth sailing.

Now, I've done a little reading on the forum and so I assume it could be the rear main seal, cam seals, or something around my valve covers?

But, why would it only burn or the first 2 seconds of the engine running?

Btw, after a drive across town I can smell a faint burning of oil when I get out of the car.

Any advice or opinions would be greatly appreciated!

josephjah

Additionally, I've got 160K miles, I had my timing belt replaced about 10K miles ago, and my engine is firing a evap sensor / charcoal canister code (which I will deal with shortly).

ThomasGS4

iTrader: (19)

Check your powersteering fluid level then report back. Sometimes a valve leaks and the engine burns it off at start up. Produces a white smoke.

macd7919

iTrader: (10)

Is it only after the car has been sitting for a bit? Overnight, while at work etc.... What about sitting at a stop light for awhile? You may need someone to watch behind you as it may be slight smoke when you accelerate from a stoplight. If you have these it could be a valve seal(s). The seals aren't very expensive but they are somewhat labor intensive. Do a google search for valve seals and Supra (mkiv supra turbos are notorious for leaking valve seals) for lots of descriptions of the symptoms.

13Checkers

If what you're seeing is blue smoke from the exhaust, valve seals are one of the first problems I would suspect, as well. Oil can slowly seep past worn seals while a car sits overnight, and burn in the cylinders once the car is started.

If it's white smoke you're seeing, that's another story altogether. White smoke is usually from coolant burning off. I've occasionally seen a slow internal coolant leak cause enough coolant to get into the intake system to burn off at start up. In that case it's usually not a head gasket leaking, as that more often than not leaks continually while running, and causes overheating, but rather a leak into the intake system somewhere.

Given the burning oil smell, though, an oil leak would be the first place to look.
The smoke is from the exhaust, and not from someplace under the hood or under the car?
...If the latter, suspect an external leak (from any of a number of possible sources, including those you list), otherwise do as macd7919 suggested, and look at the possibility of leaking valve seals.

GS4_Fiend

iTrader: (22)

If suspect leaking valves, do a leak down test

SorrGwa

iTrader: (1)

before you start doing compression tests and leak down tests, pull your spark plugs out, see if there is any oil residue. you can easily do this at home, especially on a v8. pull and inspect. if you see oil, id probably look into doing the valve cover gaskets w/ the spark plug seals. id inspect the seals at least. then you can look about doing a compression test and leak down test, on a v8, id estimate 1.5hrs to 2hrs to do each compression test or leak down test.

might as well do a visual inspection for any oil leaks. could even possibly be the pcv valve. but its all speculating.

why u see the blue/white puff for the first few seconds. chances are small amount of oil is pooling up somewhere, mixing in with the combustion. once the car is up and running, there isnt enough time to pool up more oil or whatever its burning, so hence u probably wont even see it, or just see it as regular exhaust fumes. the small amount of oil probably takes time to pool hence why only at start up.

13Checkers

Leaking valve seals and leaking valves are two different things.
Valves can be fine, but if the seals are bad, oil can leak down the stems and collect on the back of the valve... to be sucked in when the engine's first fired up.

Leaking valves can cause oil to get sucked past otherwise good seals, but if they're leaking that badly, there will be a lot more problems than just a little oil smoke on startup.

newgsman

iTrader: (4)

One thing that I noticed ever since I got my car about four years ago is that if I start my GS4 and run it for maybe only a minute or less, like if I have to move it out of the driveway or something and then turn the car off, the next time I start the car there will be a substantial puff of smoke. Otherwise the car does not smoke on start up.

I am not sure, but I am attributing this phenomenon to the oil squirters squirting oil onto the pistons on startup and because I didnn't run the car long enough some of that oil remains unburnt and will mix with another squirt of oil on the next start up which causes an excess oil burn and accompanying blue smoke.

That's my theory and I am sticking to it...

If you get bluish smoke (mine has a distinct blue tinge) every time from cold startup, chances are you have valve seal issues.

White smoke in cold weather is not uncommon at all. Sometimes it's just condensation in the exhaust pipes burning off. If you are not loosing coolant you are probably ok.

KingNasGS4

iTrader: (22)

I get a smell from the exhaust sometimes when the car is started from cold. so that's not normal then?
what's normal a normal cold start?

newgsman

iTrader: (4)

Depends what the smell is. Oil burning, coolant burning or excess gas burning each has different smell.

As far as exhaust color is concerned, normal startup is light grey.

kdick91

I'd check your crankcase ventilation first because that's quick and easy. On my LS1 Trans Am I would occasionally get this oily puff and what was happening is my PCV was (I'm assuming) a piece of crap. When the engine was warm, oil vapor would work its way through the intake manifold, cool off, and, just like condensation, would drip down and burn. I installed a catch can and everything has been fine since!! (Excluding random misfire, torque converter not locking, breaking rear ends, etc.)

Moral of the story, make sure your PCV is in healthy shape. Check the easy stuff first! If that checks out okay, be monitoring your oil level to see just how much you may or may not be losing. Really sounds like a valve seal though.