Oil leak

[PRL]

Can a blown head gasket in a Forrester cause an external oil leak?

 

[DLT09FOR]

Yes, a blown head gasket can cause an external oil leak. From underneath, you should be able to see the oil leaking from between the engine block and the head. This is from "voice of experience" -- this happened on my Forester.

 

[NotADuck]

Yes, a blown head gasket can cause an external oil leak. From underneath, you should be able to see the oil leaking from between the engine block and the head. This is from "voice of experience" -- this happened on my Forester.

I second this, from experience, BUT if you suspect a blown headgasket, but don't have an external leak, there are other means to verify. I'm not a pro, but believe through research, that it could fail internally to cause leakage into the cooling system? From reading, have seen reports of it allowing exhaust gas into the coolant, heating it substantially (overheating). This can be tested, too.

 

[PRL]

I second this, from experience, BUT if you suspect a blown headgasket, but don't have an external leak, there are other means to verify. I'm not a pro, but believe through research, that it could fail internally to cause leakage into the cooling system? From reading, have seen reports of it allowing exhaust gas into the coolant, heating it substantially (overheating). This can be tested, too.

At what point would/will the engine start to run badly?

 

[PRL]

At what point will/would the engine begin to run badly. At this point there is only an oil leak.

 

[NotADuck]

Sorry for the slow response, this is something you may want to have looked at BEFORE any performance issues, again, I'm not a pro, but with headgaskets, you may want to resolve it before any issues pop up, otherwise it may be too late