Q: Can a bad water pump cause water in the oil

asked by on

Can a bad water pump cause water in the oil

My car has 91000 miles.
My car has an automatic transmission.

Hi and thank you for your question. Water pumps are designed to pump water through the engine, radiator, and heating system. Water pumps will not cause oil to enter the cooling system. The oil coming into the water can be caused by three different things.

First, since you have an automatic transmission, the transmission fluid is cooled by the radiator. The radiator could have broke inside causing the oil to mix in the cooling system. To see if the radiator is the problem, pull the dipstick to the transmission and check the oil. If the oil is milky, then the radiator is your problem.

The second way oil can mix with coolant is though the timing cover. The cover could have caused corrosion and ate though to the water pump’s gallery. This will make the coolant mix with the oil.

The third way that oil can mix with the coolant is when the engine has blown a head gasket. However, if the head gasket is blown, the engine may overheat and have loss of power. I would check the water in the radiator, oil in the engine, and the oil in the transmission.

If you are still having trouble, I would recommend having a local expert inspect the fouled oil and proceed with any repairs that are needed.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Can a bad water pump cause water in the oil

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Top radiator hose is cold while the lower is hot

You may be correct that the thermostat is stuck closed. One way to test a thermostat is to put it in a pot of water and bring the water temperature up to the thermostat opening temperature. This is imprinted on...

Q: Just changed a blown water pump and now the truck chugs when driving and idling on my 2003 Dodge Dakota

Hello. Typically I would need to know if the engine overheated when the water pump failed. If it did then that may have caused damage to the engine. At that point I would do a compression test and a block...

Q: Why can't i fix O2 sensor problem

In many circumstances, the O2 sensors are not the only culprit of a lean fuel curve. In many cases, a clogged fuel injector nozzle can also trigger the most common OBD-II error code (P-2191) that indicates a lean condition exists....

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...