Why does muffler smoke

The most common form of smoke from an exhaust isn't actually smoke at all. When a cold engine is started, it soon begins to heat up, and a byproduct of this is water vapour.

This creates condensation within the exhaust system, which then turns into steam as temperatures rise within the engine. Once a car has warmed up, this steam soon evaporates. However, problems can occur if you only use a car for short journeys, meaning that the exhaust system doesn't get completely warm all the way to the exhaust tip.

If condensation forms in the system and doesn't clear, it can corrode the inside of the bare steel of the exhaust, leading to rust that could develop into exhaust leaks and blowing from the system - where exhaust gases leak out. This could lead to an MOT failure due to incorrect readings on the emissions test.

Because hybrid cars especially plug-ins don't always fire up the engine straight away, this can delay you from seeing steam coming from your exhaust. Depending on how much battery range you drive on, you could see steam from your exhaust well into your journey. But this again is nothing to worry about, it's just a delayed reaction to the same heating process mentioned above. If the white smoke coming from the exhaust is thicker and doesn't stop, it is still steam, but also an indicator of a more severe issue that will be caused by your car's coolant leaking into the engine.

This can be caused by a failed head gasket the seal between the engine block and the head that sits on top , which could be a pricey repair, but not as expensive as needing to repair a cracked engine block or cylinder head. If the leak is minor, but won't go away, then it will need repairing because leaving it will only make matters worse. It could even result in engine failure, which will be a very expensive repair.

This could mean replacing the engine entirely, although if it's too expensive to do this, the car will probably be written off. If you see blue smoke from your car's exhaust, it will probably be accompanied by a burning smell.

It means that there is oil entering the system somewhere. Engine oil is designed to lubricate moving parts, and it doesn't enter the fuel system if a car is running properly. If your car has been serviced recently - or you've serviced it yourself - it could be that too much oil has been put back into the system, and this excess oil is burning off. If the smoke stops after a while, then there's no problem.

Another cause could be that some oil has spilled onto the exhaust while being topped up, only to be heated and burnt off by the hot exhaust while you're driving.

If the blue smoke is happening in a car that's covered a high mileage, it might mean that the valve seals or piston rings are worn, which is allowing oil to enter the fuel system around the cylinders or valves.

The remedy for this is new seals all round, and as you'd expect, this is a costly job as it means taking the engine apart to get to them. Burning oil will also mean you're using more oil than normal, so it's worth checking the dipstick more regularly to see how much oil loss is occurring. If it's minor, then simply topping up with oil will be easier than repair, as long as the oil loss doesn't get any worse.

If you're seeing blue smoke from a turbocharged car, then another reason for it could be a worn-out turbocharger. This will need rebuilding or replacing, which is also an expensive job. The rpm sounds common between us. The leak down test is a good idea. I have a Mercedes Benz Viano 3. When I put diesel in and the needle is above quarter its smokes. I will take it for a drive about 20 km and when I get back the smoking has stopped. It will be gone for about a month to 2 months and then start smoking again.

Can this be a result of faulty injectors. I have Ford Focus…First sign of problem the Ac stopped.. I pulled into parts store.. Within 5 miles engine stayed cool but now thick white smoke from exhaust. I did spill oil into spark plug reservois. I changed plugs wiped out oil.. Any suggestions???? HI BMW i touring I have random white puffs of smoke from exhaust.

Driving along happens at approx 15min intervals. I have had a oil leak for ages 2 rocker gaskets, 2 vacuum pumps, o rings now rocker gasket and rocker cover about a week ago, seems to have cured leek but the puffs of smoke started a couple months ago. Thought the oil leek was the cause.

Any ideas. Thank you. My Nissan Pathfinder started to have a cloud of white smoke come from the exhaust on startup, but went away in a few seconds. I parked the car for a few weeks, and checked all fluids, checked for any leaks, and ran Seafoam through the gas tank. I checked my plugs and all look great. Stopped smoking at startup so I drove the car to work. Now the smoke is continously coming out. The smoke is really thick. Any ideas? I bought a f It was from a used car lot.

I noticed today cool day and I did not use the ride 4 about 2 days alot of white smoke came out tailp, it subsided but continued to come out duration of drive. I found out that this ride came from an auction. See if the white smoke persists. I have a uno model it is making thick white smoke even while driving non stop and it has a bad smell what can it be firstly.

My 95 Lexus had some fuel injection cleaner fluid put in a month or so ago , driving miles away from home it started to smoke out , did the fuel injectors clean out? White smoke can be burning oil, can be a bad mix also.

I had white smoke, thought it was injectors. I replaced the mass airflow sensor and it was gone almost instantly. Rich exhaust smell also disappeared. It could be a leaky intake manifold gasket or a leaky head gasket. I would do a bit of testing or take it to a mechanic so you know for sure before replacing anything. My car started blowing white smoke from exhaust. Went to get an oil change the next day and was told there was too much oil in there.

They told me to drive the car around to get rid of the white smoke. Is that true? If so how long should I drive it around? I am considering a Saab and the seller says the white smoke, which clears up in less than a minute, is caused by the age of the turbocharger. Is this likely a cause, and what else might it be caused by?

I have a buddy who had a turbocharged beetle that would blow a little white smoke whenever he would get on the throttle. Book a service. Upcoming Cars. Best of Stoneacre. Other articles from the Stoneacre Blog. Advice Centre Hydrogen Fuelled Cars do they have a future? Lisa Simm 22 Mar Sam Bisby 16 Mar Lisa Simm 27 Jun Sign up for our newsletter to receive our latest news and offers How will we use your email?

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