Hi everybody,

 

I have a mechanic friend that called me today to ask if Subarus leak oil from the top of the head gasket. He is working on a 2001 Outback, that came in with oil polled on the top of the engine, and running down the back of the engine.

 

He was expecting it to be the oil pressure sending unit when the customer said they had oil on top, but he says this is more toward the rear. He wondered if they ever leak from the knock sensor. I said I had never heard of an HG leak on top. He is sure it is not the valve cover gaskets.

 

So I told him I would post a question and see what you all come up with. Any ideas?

Might be power steering fluid. Sometimes a leaky power steering hose can spill on the top of the motor.

I replaced my Knock sensor. It does not appear to be internal to the to the engine at all. Basically, it sits on top like stethoscope.

Might be power steering fluid. Sometimes a leaky power steering hose can spill on the top of the motor.

 

He says it's oil. He doesn't know Subarus very well, but he does know oil .

I replaced my Knock sensor. It does not appear to be internal to the to the engine at all. Basically, it sits on top like stethoscope.

That's the way I remembered it from replacing one on my 97, but that was years ago. Thanks.

There is an oil galley plug towards the rear of the engine under the intake, but I think it's on the passenger side. Uses an aluminum crush washer to seal.

My 2001 seeps oil from the top of the passenger side HG. It isn't enough to cause a puddle, just enough to be damp and collect dirt.

Probably oil sensor ( idiot light)they go bad, behind alt.

Thanks everyone. I talked to him today. He knows about the pressure sensor, and this oil was not coming from the front of the engine. After cleaning it off, and letting the car run, he said it didn't take long for it to create a new puddle! That's a lot of oil. He was convinced that it was coming out of the top of the head/block seam, and told the customer as much. They are deciding what they want to do now. This was a new one for me.

I had this exact problem on a CCR rebuilt engine within the first 1000 miles, top left front and right rear both had pooling oil that would run down the back and drip on the exhaust, didn't have the problem long though as that engine finally threw a rod thru the case (making a bigger leak...). Their offered solution at the time was to send it back to them so they could fix it but it wasn't that appealing to pull the engine again and be carless.

After several head gasket issues on 2000-up engines, we stopped using the gaskets that come with the engine gasket kit and now only use turbo head gaskets on all newer style engines. It costs us a bit more, but we have had exactly zero issues since then.

 

My advice is to make sure to only use the turbo head gaskets. The "recommended" gaskets are too thin and flimsy. If I was actually at work today (home sick), I'd post the part number for you. I'll do that when I get back to the office where our build sheets with part numbers are.

 

ps: We DID offer to warranty the engine for you. That much oil loss was bound to cause problems.

After several head gasket issues on 2000-up engines, we stopped using the gaskets that come with the engine gasket kit and now only use turbo head gaskets on all newer style engines. It costs us a bit more, but we have had exactly zero issues since then.

 

My advice is to make sure to only use the turbo head gaskets. The "recommended" gaskets are too thin and flimsy. If I was actually at work today (home sick), I'd post the part number for you. I'll do that when I get back to the office where our build sheets with part numbers are.

 

ps: We DID offer to warranty the engine for you. That much oil loss was bound to cause problems.

I will pass this along to my friend. I gather he doesn't do HG jobs on Subarus, which is good, because his shop really isn't set up well for it, but good info for him anyway. So is this what you guys are doing on gen 3's also? Turbo HG's? Just thinking ahead in case my '09 ever betrays me. My CCI engine served me very well, and is in fact still running around the Western Slope.