I have motor oil leaking into my overflow tank. What could the problem be? How can I fix it?

It was already determined that it is oil and not old antifreeze. The mechanic said it was the head gasket. He said if it is cracked, it needs to be replaced. Wouldn't it be cracked anyway if there is oil going into the expansion tank?I have motor oil leaking into my overflow tank. What could the problem be? How can I fix it?
Not necessairily-could just be seeping past a burned out piece of the gasket.The head itself will need to be checked by a machine shop-they use a UV dye-for cracks and warpage.


Your mechanic was referencing the head gasket for definite replacement and the head for removal/inspection/possible replacement. Good time to give the cooling system an overhaul-check water pump, flush radiator, new thermostat, new coolant, new radiator cap, etc.


Makes sense to check/adjust the valvetrain, while the head's being r%26amp;r'ed. Basic tuneup, too.


Head gaskets aren't too hard, but sometimes you find you've opened a can of worms, know what I'm saying?I have motor oil leaking into my overflow tank. What could the problem be? How can I fix it?
Your mechanic is correct. You have what is known in the industry as a blown head gasket. It could be a cracked head too. Hope it isn't. Either way you have an expensive repair bill coming.





If I were you I would first decide how much the car is worth. If the cost to repair the car is more than its worth you might be better off getting another vehicle.





You never mention what year or brand of car you own so I can't tell you if it is something you might be able to fix. You could try and find a Tech school in your area to see if they would fix it for you. However they take there time on things as it is a learning experience for the students.





I wouldn't keep driving this car either as if you get to much oil in the water you could blow the engine. I wish you well with your problem...
Head Gasket needs to be replaced
Yes! you have a major problem. Every thing needs drained%26amp; fixed at once or all will be ruined.
blown gasket. expensive to fix, but engine will seize if you don't.
I would take the advice from cape nut, I would have told you basically the same thing
It's a virtual certainty that the oil in your header tank is there because of a failed cylinder head gasket. You need to have a fair amount of experience to fit a replacement but, with the right tools , a Haynes repair manual would probably help you to do it. However it could mean that where the gasket is leaking it will have damaged the mating faces of the cylinder block and cylinder head which will necessitate having one or both skimmed. Generally speaking a new gasket will not compensate for damaged faces of these 2 major components. You should either get the repair done ASAP or do it yourself. Don't continue to run the car until this is done. It may be, too, that water is finding its way into the sump which tends to emulsify the oil and this doesn't enhance its lubrication properties. Small point...I guess the mechanic used the word ';might'; because he didn't want to take on the repair. In my opinion water in the oil needs fixing urgently. Good luck.
HEAD GASKET...............................





Some engines just have a history of blowing head gaskets.





Some head gasket failures can be blamed on a hard-to-seal cylinder head.





Overheating is also a very common cause of head gasket failures. If the engine gets too hot, the cylinder head can swell to the point where it crushes the head gasket (usually between the cylinders because this is the thinnest point). The extruded material and/or cracked combustion armor then provides a leak path for coolant and/or combustion gases.





Another common cause of head gasket failure is excessive pressure in the combustion chamber. This can be the result of detonation and/or pre-ignition.
The only way you can fix it, would be to replace the head gasket.





Sometimes that costs more than just getting a new engine or another car, unless you know some good mechanic that you are friends with.