My car keeps blowing smoke ONLY when I start it!?
I just bought a new car, and I’ve noticed it it’s been sitting there a while (off) when I crank it up it blows smoke! But it only does it when I start it up. I thought it could be the oil...but I’m sure if it’s burning oil it would do it the whole time the car is on. And when I checked the oil, it’s not black like it would be if it was burnt up...it’s the normal brownish see through color...Also important to note that the person who owned the car before me put in a larger cold air intake... it’s much larger than a stock intake would be. It is kind of dirty, and I’m sure I should change it out soon? My boyfriend thinks maybe the smoke could be from that? Idk were not mechanics. So maybe someone could help and save me the trouble and worry. Because maybe it could be nothing? HELLPPPP
- Road warriorLv 46 months ago
Could be intake is causing it to run a bit rich on starting. Maybe choke flap not adjusted right? Could also be valve guides. Maybe the breather is off or on wrong if the intake was modified, too. If PCV valve and setup loose or wrong, then instead of drawing sump vacuum, oil in valve cover baffle from sitting overnight sucked into manifold on starting.
- JetDocLv 76 months ago
If someone else owned the car BEFORE you, then it's NOT a "NEW" car, Skippy. It's a USED one!
What COLOR is the "smoke" you see? If it's WHITE, then it's not smoke at all. It's STEAM from the moisture condensing in your exhaust system, and it's NORMAL. If the "smoke" is blue, then it's oil being burned inside the engine, and you should have the system checked by a competent mechanic.
- thebax2006Lv 76 months ago
You didn't buy a new car...you bought a used car.
How many miles on it? You describe the symptoms of bad valve guide seals. When the motor is shut off for a couple of hours oil drains past the hardened valve seals and gets into the cylinders and burns for a few minutes at start up.
A valve job would fix it.Source(s): Mitsubishi Mater Tech
- BertstaLv 76 months ago
Oil smoke on start up is worn valve guide oil seals. The oil in the cam lobe recesses leaks down past the valve/seal and collects in the cylinder. When you start up, it burns off. It burns oil all the time btw, but obviously there is more oil (and visible smoke) after it has been siting a while than when it is running. Your oil doesn't go black because it isn't being recycled back into the motor. Keep checking your oil level to gauge just how much oil you burn. If it only needs the occasional top up it's not worth spending money on the repair. Your car has had some hard use. People who fit cold air intakes really want a Maserati but can only afford a Mazda, and think a cheap Chinese filter will unleash the extra 368 bhp they are missing. You may want to be extra diligent with oil changes to get the most life out of it. As a rule, if anything's dirty, change it.
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- Anonymous6 months ago
Ignore all these stupid scare stories. Most cars smoke on start up. It's excess fuel which is needed to start the car and water vapour from a cold engine. If you get no smoke when the engine is at normal temperature you have no worries. Half the people on here are away with the fairies.
- gLv 76 months ago
White exhaust smoke is an indication that coolant is burning in the combustion chamber. These are possible causes:
Cylinder Head: A crack in the cylinder head (around the coolant jacket) will cause coolant to enter the combustion chamber.
Engine Block: A crack in the deck of an engine block near the coolant jacket will cause coolant to enter the combustion chamber.
Head Gasket: A damaged or blown head gasket will cause coolant to enter the combustion chamber resulting in white/gray smoke coming from the tailpipe.
- ErikLv 76 months ago
If it only does it when you start it up, and it drives fine aside from that, it's probably nothing. If it's an older car, it may be burning oil, so make sure you check the oil level at least once a week.
- Anonymous6 months ago
That's a common symptom of worn valve guide seals and / or worn valve guides. Replacing the seals is a relatively easy and inexpensive job. If the valve guides are shot then it needs the head removed and machined. If it only smokes at start-up and not noticeably at any other time, then it's probably just the valve seals.
When the engine sits for awhile, oil on top of the cylinder head [which is normal] leaks past the worn seals, down through the valve guides and into the cylinders. That is what smokes on start up but once it burns off you see little if any more smoking. To replace the seals requires removing the valve cover[s], removing the valve springs and retainers and replacing the rubber seals. It's not a job for an inexperienced person lacking the proper tools including a valve spring compressor.
If you don't fix it, the cylinder or cylinders that have the problem will keep coking up with the residue of burned oil that at minimum will foul the plugs, may cause pre ignition or detonation or missing, and at worst eventually cause the valves to not close properly, reducing the engine compression and performance further.
I hate to say it but you probably just bought a pig in a poke. Hopefully not. GOOD LUCK
- Anonymous6 months ago
Better check the engine. Don't want it to start rattling.