Engine Rattling Heavily

3. Water in the oil.

Diagnosis = headgasket failed allowing water from the cooling system into the engine combustion chambers, that's what is causing the rough, shaky engine and water in the oil.

Your mechanic doesn't sound like a very competent one. You should seek out another.

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how many miles on her? ever cleaned the egr circuit? does she burn any oil?

 

Fixes:
1. Drained all the oil. Replaced oil and oil filter. Dip stick showed no water this time.
2. Replaced all the four ignition coils.

Number 1 sounds absurd. If you replace the oil and the oil filter, it would not show water. Water (coolant) gets in there when there's a bad headgasket, changing the oil doesn't fix a darn thing.

Number 2, well you should replace the spark plugs too, after you fix the headgasket of course.

 

Unfortunately back in January it may have been just a head gasket.

Now the very common head gasket problem has progressed. Water in the oil is end stage. Have to assume there is very serious piston damage by now. A used or rebuilt engine or junking the car is in its future.

The problem does not present in the same way conventional cars do with a failed head gasket. An all aluminum engine often warps the head. Confuses uninitiated mechanics and dismayed owners almost every time.

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