Kohler Command Engine Oil Leaking Problems

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Does your Kohler Command engine leave trails or puddles of oil behind? I understand how frustrating oil leaks can be!

Your Kohler Command engine oil leaking problems could be a result of issues such as worn seals/gaskets or cracked oil blocks.

In this article, I talk about simple and easy-to-follow DIY troubleshooting tips to help you diagnose these issues and fix your Kohler Command engine oil leaking problem.  

Reasons Why Your Kohler Command Engine Leaks Oil

Your Kohler Command engine may leak oil due to the following reasons:

  • Worn crankshaft seal
  • Saturated air filter
  • Blown head gasket
  • Warped cylinder head
  • Blocked crankcase breather
  • Broken valve cover gasket
  • Worn/misaligned oil filter
  • Loose oil drain plug
  • Cracked oil pan

Tools You Need For This Job

Some tools you may need to diagnose the problem include:

  1. Work gloves
  2. Screwdriver
  3. Pliers
  4. Compressed air
  5. Clean rag
  6. Soft faced hammer 

Kohler Command Engine Oil Leaking Problems: Causes, Diagnosis, and Fixes 

1. Worn Crankshaft Seal


A worn crankshaft seal is the most common culprit for oil leaks. 

The crankshaft seal keeps oil from escaping outside the crankcase as it is being tossed around in the crankshaft.

Like other rubber engine components, the seal dries out and gets brittle over time due to the heat and friction between the crankshaft and the timing cover.  

Excessive oil in the engine also increases crankcase pressure and may cause seals to leak.


An oil drip on the front side of the engine may indicate a worn crankshaft seal. 

Furthermore, the oil may spatter on the clutch, causing it to slip on occasion.

If you notice any of these, inspect the crankshaft seal and replace it if it appears dried or cracked.


Reduce the oil level if it is in excess.

Replace the worn seal with a new one.

How To Replace Crankshaft Seal On A Kohler Engine


To install a lawn mower  crankshaft oil seal, first drain the engine oil, then:

  • Unscrew the front of the mower to access the engine.
  • Pull the spark plugs out.
  • Remove every screw holding the engine to the mower.
  • Pulleys and tabs covering the oil seal should be removed.
  • Use compressed air to blow away the dirt and debris.
  • Make use of a metal tool to tap between the oil seal.
  • Once it becomes loose, pull it out.
  • Grease the new oil seal’s interior surface.
  • Install the new oil seal with a soft-faced hammer.
  • Reinstall the engine and replace all the screws.
  • Fill with new oil.

2. Saturated Air Filter


A foam air filter must be coated with a light layer of oil to enable it to catch dust and other particles.

However, an oil-saturated filter can spill some of that oil around the filter housing and out of the mower.

The air filter can get saturated by tipping the lawn mower wrongly. If you notice oil leaks around the air filter housing, this might be the problem.


Take out the air filter housing and inspect the air filter. If it is soaked in oil, it is over-saturated.


  • Squeeze out excess oil and wash the air filter, or replace it.
  • Tip your mower with the air filter side up to avoid oil leakage. 

3. Blown Head Gasket

The head gasket, a piece of coated, perforated metal, seals the gap between the cylinder and engine block, creating the vacuum required for combustion to continue. 

Oil may leak through your Kohler Command engine if the head gasket breaks or wears out.


Open up the engine and check the head gasket. If you notice a line or pool of oil around where the two parts are held together, the head gasket is blown.


Replace the blown head gasket. 

4. Warped Cylinder Head

A warped cylinder head can cause gasket failure, oil leaks, and more.

Warped head gaskets are caused by overheating. These warped pieces of metal change their shape and may damage the gasket, resulting in oil leaks from your Kohler command engine.


If the head gasket is damaged, inspect the cylinder head. If it is warped or distorted, it may be the problem.


  • Take the engine to a small engine repair shop to repair the cylinder head. 
  • Replace the head gasket if it has been damaged.

5. Blocked Crankcase Breather 

The breather tube has a reed that collects the oil that lubricates the piston, and it directs the collected oil back to the crankcase. 

The tube can become clogged with dust and other debris over time.

If this happens, the oil flow will be diverted and move toward the cylinder walls, resulting in an oil leak. 


Blow air through the alleged breather tube to determine whether or not it is flowing smoothly. Examine the breather gasket for signs of wear.


  • Clean the breather tube of any debris using compressed air.
  • Replace the breather if it is cracked or severely clogged.
  • If the breather gasket is cracked or damaged, it must also be replaced.

6. Broken Valve Cover Gasket

A broken valve cover gasket can cause oil leak problems in your Kohler Command engine. The valve gasket keeps oil from leaking out of the valve cover.

It is a rubber/silicone gasket that helps seal the joint between the valve cover and the rest of the engine and keeps the oil inside.

A valve cover gasket is delicate and can get worn/broken with frequent exposure to heat, causing oil to leak out of the valve cover.


Examine the valve cover to see whether the valve cover gasket is leaking any oil. 

The valve cover gasket is worn if the valve cover/cylinder head is really dirty or if oil and debris seem caked on the valve cover or cylinder head.


Replace the valve cover gasket.

7. Worn/Misaligned Oil Filter

Kohler engines have an oil filter that can deteriorate and gather slime and particles over time.

Additionally, your oil filter may become misaligned or, if you recently had your oil changed, your new oil filter may have been installed incorrectly.


  • Check the filter for dirt and particles that may be clogging it. 
  • Check to see if it is positioned rightly.


  • Replace a clogged/worn oil filter. 
  • Place the filter tightly in the right position.
  • Try to change the filter at least once every season to prevent clogging.

8. Loose Oil Drain Plug

The oil drain plug is usually removed when changing the oil so that all of the old engine oil will drain out of your car.

The drain plug can wear out or become loose over time and cause oil to leak out from it.  


Check the drain plug to see if it is loose or if oil is leaking from the plug.


Tighten the plug or replace it if damaged.

9. Cracked Oil Pan

The oil pan holds engine oil, which circulates through the engine to lubricate and cool moving parts. 

The oil pan gasket seals the oil pan to the engine block, keeping oil from escaping as it flows from the pan to the engine and back again.

Oil leaks are frequently caused by a cracked oil pan or a leaking oil pan gasket. If this is the problem, you would lose a lot of oil because it would be a direct leak as the engine oil sits on the oil pan.


Inspect the oil pan and pan gasket for cracks and holes.


  • Replace the oil pan gasket if it is broken. 
  • Replace the oil pan if it is cracked and leaking oil.

Frequently Asked Questions

1. How do I fix an oil leak between the engine and transmission?

The most common causes of oil leaks are broken gaskets and leaks in the oil pan. Look for damaged components and replace them to fix the oil leak.

2. Can an oil leak cause a vacuum leak?

Yes, an oil leak can cause a vacuum leak. Oil leaks damage gaskets and seals which helps to build a vacuum in the engine, resulting in a vacuum leak.

3. How do I drain oil from a Kohler engine?

You can drain oil from a Kohler engine by making use of the oil drain plug. The oil drain plug is located near the oil☺ filter. 

4. Why is my lawnmower leaking oil from the bottom?

Your lawnmower leaking oil from the bottom could be due to worn/broken seals or a cracked oil pan.

5. How do I clean oil leaks in the engine?

A degreaser can be used to remove oil leaks in an engine. Spray a degreaser on the engine parts, then wait for it to absorb the oil.


The reasons your Kohler command engine leaks oil may be a worn crankshaft seal, saturated air filter, blown head gasket, warped cylinder head, blocked breather, broken valve cover gasket, worn oil filter, cracked oil pan, or a loose oil drain plug.

You can diagnose and fix your Kohler command engine oil leaking problems by following the troubleshooting guides in this article and applying the recommended fixes.