Why Your Lawn Mower Blows Blue Smoke.
There are a few things that can cause your lawnmower to smoke, and while it may appear to be a major problem, it is usually a simple fix. If you follow this simple checklist, you should be able to self-diagnose the problem, fix it, and get back to your lawn in no time.
The mower blows out Blue or White smoke.
The engine may continue to run like this for a while, but it will eventually clog up, become increasingly difficult to use, and eventually die.
Has the oil reservoir been overfilled?
If the oil level is higher than the maximum full lever on your dipstick, you’ll need to drain some oil from the mower, which you can do with an oil extractor pump or by unbolting the sump plug.
Finding the sump plug.
To remove the spigot, I usually use a socket wrench without a scoket, but it can also be done by hand with a screwdriver or similar tool for ease of access.
Has the mower has been tipped on its side?
If your mower has been tipped on its side, let it idle for five minutes to see if it clears up. If it is full of oil, clean the holder and replace the air filter.
Is the choke working correctly?
Check the cable attached to the on/off switch to make sure it is not stuck in the choke position, and lubricate the top and bottom of the cable. If you have an automatic choke, have it checked at your local mower shop.
Ware and tear on the engine.
This could be any excessive engine wear, but it’s usually a worn cylinder, rings, or a blown head gasket, all of which should be checked out by a qualified mechanic.
The air filter may be blocked.
If you have a foam air filter, you can wash it in warm water with a few drops of dishwashing liquid, then place it in a plastic bag with a small amount of Foam air filter oil and squeeze the bag to distribute the oil evenly.
Your air mix on your carburetor needs adjusting.
The idle screw on your carburetor is a screw that you can turn to adjust the idle speed of your engine. It can slow down if it’s idling too fast or speed up if it’s not working properly.
You may have an incorrect gap in your spark plug.
If your spark plug is carboned up, clean it and double-check the gap in the plug. If you have any problems, I usually just throw a new plug into the mower. They are only a few dollars each, so it’s always worth having one on hand.
A Faulty crankcase breather.
You’ll probably want your local mower shop to do this for you unless you’re handy with engines; there’s a video below that walks you through the process.
Two-stroke engines blowing smoke.
You don’t want to just add petrol to dilute the oil mix; if the engine stops smoking, you’ve found the problem. Nobody likes a smoky mower, and you don’t need one any longer.
Why is my tractor blowing blue smoke?
The mower produces blue or white smoke, which indicates that the engine is burning too much oil. Excess oil causes incomplete combustion, which results in smoke and carbon buildup.
How do you fix a blue smoke from a diesel engine?
Clean the engine. Blue smoke can be caused by a clogged cylinder head; to clean it, remove the valve cover and clean it thoroughly; also, clean the drain back holes carefully and recheck and reassemble them; and finally, wait 2 or 4 days for the remaining oils to clean away.
Why is my diesel engine blowing blue smoke?
Blue engine smoke is the rarest type of smoke produced by a diesel engine, and its presence indicates the presence of burning oil. Blue smoke is common when starting an engine in cold weather because the oil thins out and some may escape into the cylinder and be burned.
What does it mean if you see blue smoke from the exhaust?
Blue Exhaust Smoke If you notice blue smoke coming from your exhaust, your engine is burning oil due to an oil leak, which could be caused by a leaking valve seal or a piston ring issue.
How do you fix blue smoke from exhaust?
The Cost of Fixing Your Blue Smoke Problem Depending on the source of the problem, you’ll need to replace your glow plug, head gasket, valve seals, piston rings, or PCV valve.
Would a bad injector cause blue smoke?
Blue smoke is usually caused by engine oil entering and burning inside the combustion chamber, but we see issues related to worn injectors more often than not.
What does blue smoke from exhaust look like?
Blue smoke can appear grey at first glance, but if it has a distinct bluish tint, it could indicate that the engine is burning a lot of oil, which could be caused by worn engine components such as piston rings, valve seals, or PCV (Positive Crankcase Ventilation) valves.
Can too much oil cause blue smoke?
Oil leaking past engine seals and into the cylinders, where it mixes and burns with the fuel, is the most common cause of blue exhaust smoke. It only takes a small amount of oil leaking into the cylinders to cause excessive blue exhaust smoke.
Can diesel injectors cause blue smoke?
Wearing valve stem seals cause smoke at start-up and idle regardless of engine type, but constant blue smoke on a turbocharged diesel is more likely to be caused by a faulty injector pump and/or lift pump (which allows engine lubricating oil to mix with the diesel).
What does GREY diesel smoke mean?
Simply put, diesel cars emit grey smoke when they don’t have enough oil. In addition to being a sign of too much oil burning in your diesel engine, the smoke could also indicate: A faulty PCV (Positive Crankcase Ventilation) valve u2013 This part is responsible for emission control.
Is it normal for a diesel to smoke?
Normally, diesel engines should not produce much smoke while operating; however, some older diesels are known to emit smoke when accelerating under load.
Can a bad O2 sensor cause blue smoke?
The O2 sensor cannot cause your engine to smoke when it is working properly; however, if your car runs excessively lean for an extended period of time, serious engine damage can occur, resulting in black, white, or blue smoke from the exhaust, but you will usually be alerted to other symptoms first, such as rough running.
What color smoke is a blown head gasket?
Exhaust smoke is the most common sign of a blown head gasket; white smoke indicates that coolant is leaking into the cylinders, while blue smoke indicates that oil is leaking from the gasket.
Can a bad EGR valve cause blue smoke?
The exhaust gas recirculation (EGR) valve may stick from time to time, causing blue smoke. When it sticks open, it allows spent exhaust gases to enter the engine, interfering with combustion but also causing other symptoms such as rough idle and possible EML warnings.