Tag: oil leak on push mower

Push and Self-Propelled Lawn Mower Repair

Self-Propelled Lawn Mower Leaking Engine Oil

There are several places that a self-propelled lawn mower can leak oil form. The most common of those places is from the carburetor. Yes, the carburetor. When you overfill the engine oil, it will be sucked into the crankcase breather and then into the breather tube and into the carburetor. Then that oil will drip out of the carburetor and it can also get ingested into the engine and burned up. This will also cause the engine exhaust to burn a light blue color.

Another place is the rocker arm cover. The seal can become split or the bolts holding the cover on can loosen and cause the cover to leak. First, check the bolts to see if they are tight and if they are, check the integrity of the seal.

Oil can also leak at the crankshaft seals. There is a seal at the bottom of the engine and the top is sealed by a tight fit between the crankshaft and the crankcase.

The last place is at the crankcase itself. An item such as the governor arm protruding through the case or the crankcase gasket itself will leak.

Now that you know where the majority of leaks occur from on a self-propelled lawn mower engine, you can find a small engine repair shop near you on our Locations page.

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Lawn Mower Leaks Oil From Crankcase

Occasionally we see an oil leak from the crankcase gasket that seals the two halves of the crankcase together. Or a pinhole develops in the actual casting of the crankcase and oil will seep out of it. Other areas that leak are protrusions through the crankcase such as the governor arm shaft. Head gaskets can be another source of an oil leak out of the crankcase. An oil seal at the crankshaft is another oil leak source.

Note: Be extra cautious during the testing as you are working near a lawn mower blade. You can shutdown the engine prior to checking for where the engine is leaking for safety.

There are some dyes that can be added to the oil to find a hard to find oil leak. You put the dye in the crankcase and run the engine to get it warmed up. Then a black light is used to identify where the oil leak is coming from.

If you don’t have access to this type of testing paraphernalia, thoroughly clean the engine crankcases and then run the engine until it is warm. Look over the areas that you suspect the leak is coming from and look for the slightest weeping of oil. Wipe the area down and continue to monitor it.  Some leaks are difficult to find, but you will eventually find them.

Push and Self-Propelled Lawn Mower Repair

My Push Lawn Mower Leaks Oil

 

An oil leak can be a serious problem for your push lawn mower. If too much oil leaks from the engine, it could damage the crankshaft and connecting rod. To avoid that damage, let’s look at a few areas to see if we can determine where the leak is coming from.

If the oil is on the deck in the front of the engine, chances are it is coming from a valve cover gasket or the head gasket. It could also be seeping from the crankcase gasket.

If the oil is coming from the side of the engine, it could be the crankcase breather is leaking or the crankcase gasket is seeping.

If the oil is leaking down from the top of the engine, the seal or bearing surface is worn out at the top of the crankshaft.

If the oil is leaking from the bottom of the engine, the seal or bearing surface is worn out at the bottom of the crankshaft.

In each of these cases, the leak can usually be repaired. If the leak is on the top of the engine, it might not be possible to repair it if the crankcase is worn and oil is leaking by it.

On older Tecumseh engines, the crankcase breather is on the top of the engine and that can be replaced to stop the leak.

Visit our locations page to find a push mower mechanic in your area.

Finding and stopping the oil leak on your push mower is the only way to save your valuable engine.