what would cause coolant to mix with oil in engine?

What is your question?

Coolant mixing with oil. Replaced head gasket. Didn’t fix problem. Smoke tested. Don’t know the source of the problem

What makes this problem better or worse?

Nothing so far

How long has your 2016 Mazda 6 had this problem?

Car been down for 3 months

Visitor

in Pomona CA

Jul 25, 2020

2 Replies

Popular Answer

DaveJMon Jul 26, 2020

A 2016 model with problems like this? How many miles are on this engine? Why did you replace a head gasket -- what kind of testing was performed?

pushrodon Jul 26, 2020

The *INTERNAL WATER PUMP* is leaking coolant straight into the oil pan ! Why wasn’t some old fashioned testing performed BEFORE attempting repair??

pushrodon Jul 26, 2020

Pump is located BEHIND timing cover - driven by the timing chain.. Furthermore it is pretty much a fallacy that a failed head gasket is automatically what causes coolant mixing with engine oil .. Even with pushrod engines in vehicles of yesteryear.. I have concluded the real problem was corrected ‘during’ head gasket replacement.. INTAKE MANIFOLD gaskets were the actual culprit, majority of the time.. First thing that is said when coolant is present in crankcase oil - “BLOWN HEAD GASKET” - - well NO - not necessarily !

pushrodon Jul 26, 2020

Some additional information I found: https://www.carcomplaints.com/news/2019/mazda-water-pump-lawsuit.shtml Those I have seen were H2O pump ‘gasket’ failure. Good luck!

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