Auto Repair Advice by Professional Automotive Experts
Troubleshooting
/
Why is There Coolant in My Oil?
Why is Coolant/Antifreeze in My Engine Oil?
An engine depends on coolant/antifreeze to help to stay cool. The engine
generates heat from the continuous internal combustion process. Coolant and
antifreeze are the same thing; manufacturers call it by different names. Coolant
runs throughout the engine block, cylinder heads, intake manifold (Some
applications), engine oil cooler (if equipped), hoses and the radiator. Pin
pointing the cause of coolant in the oil can save you in repair costs and help
you make a decision on performing these repairs. One of the biggest obstacles is
to determine where the internal engine coolant leak is located. If coolant is
present in the engine oil, engine failure is eminent. The engine cannot run with
coolant in the oil system. Once coolant is discovered in the engine oil do not
run the engine. To check if coolant is present in your engine's motor oil,
remove the oil fill cap. Once the cap is removed turn the cap over, does it have
a light gray or milky colored goo inside? If so, you probably have an internal
engine coolant leak. We have listed many common causes below:
Car Repair Guide - READ COMPLETELY BEFORE BEGINNING
- Step 1 - If your car is equipped with an engine oil cooler
that uses coolant to operate this would be a good place to start. Sometimes
an engine oil cooler can act like a one way valve. When the engine is not running but
is still hot the cooling system
will have about 15 pounds residual pressure forcing coolant into the engine. The
GM manufactured 3.0 V6 in Saturn and Cadillac and
VW products are
prone to this problem. This problem can be repaired by replacing the engine oil cooler.
Once the oil cooler has been replaced you must
replace the engine oil and filter and recheck.
- Step 2 - Anytime you have
coolant in the oil and it's not the oil cooler it means the engine must
be disassembled to locate the failure. The next options are not so pretty.
There are three remaining causes for coolant in the motor oil and all require engine disassembly.
This can be tricky because the repair overlaps and it is difficult to
tell which one is causing the problem. For example: A repair shop has told you
the cylinder head is cracked, and as they start disassembly they can discover
it was the intake manifold gasket that has failed. It's up to the honesty of
the repair shop to inform the customer that the cost of the repair will be less. Or the opposite
can happen, example: A repair shop has told your engine has a blown head gasket,
once the disassembly is complete they inform you the head gasket is ok, and
the cylinder has been pressure checked and is ok. This only leaves the engine
block as the failure and must be replaced to repair the problem, and that can
be very costly. Always check the intake gasket first on V6, V8 and V10 engines.
Then the cylinder head gaskets, cylinder heads and finally the engine block.
For exact specific repair procedures for any of the steps above visit our
online repair
manual page.
Troubleshooting
/
Why is There Coolant in My Oil?
Additional Resources
Check Manufacturer Specific Coolant
in the Engine Questions and Answers
Related Subjects
ASK A CAR REPAIR QUESTION -
Join our question and answer forum where over 6,000 free auto repair questions
are answered every month, after you have completed our free signup you will able
to ask a question and receive an answer from one of our many forum members. If you
elect to donate any small amount of money we will assign one of our 2CarPros Certified
Repair Technicians to answer your question. Questions with donations are answered
promptly and 100% of the donation is awarded to the technician helping you.
GET AN ONLINE
CAR REPAIR MANUAL
- Get instant access to your vehicles wiring diagrams, firing orders, component
locator, vacuum diagrams, repair procedures, specific testing and diagnostics for
troubleshooting, steering and suspension information, heating and air-conditioning
problems, safety belt and airbag restraint repair, factory bulletins and general
information and much more. We recommend that anyone needing technical repair information
should have a quality auto repair manual for their car.
|
