2006 Subaru Impreza 2.5- Cam seal malfunction?


I purchased a 2006 Impreza 2.5 back in July, and since then, have replaced the cam seal twice but I am still having problems. I smell burned oil and see faint smoke coming from the motor (lookers right- battery side). My local mechanic thinks the camshaft might be at fault, but is unsure. I have only owned Subarus, and have never had this issue with any other models. Head gaskets are brand new, same with timing belt, water-pump, radiator, and cam seal. Vehicle has 160k on it, and is my daily driver. Any help or suggestions would be much appreciated, as this car is still under warranty for major repairs only, but time is ticking.

Thanks for reading.

How about the oil pressure switches. Apparently the engine has a left and right “Variable Valve Lift Diagnosis Oil Pressure switch”.

Would that cause the motor to burn oil and give off smoke coming behind the timing cover? I have yet to see an engine light come on, so I’m not sure if it is pressure related. The latest cam seal was installed 2 weeks ago. The engine bay and front skid plate were cleaned of burned off oil, so the recent oil I’ve seen building up and burned smell, happened since my last oil change, which was also 2 weeks ago.

Have you looked to see if you can see where the oil is coming from? Any oil on the engine will smoke and smell. Did you smell the oil right after the change? Take a flashlight and look around.

If your mechanic removes the valve cover to replace the seal, it wouldn’t be much effort to set up a dial indicator and check if the camshaft is true or not.

Also if he’s putting the seal in dry…he may want to give it a very light coat of RTV Blue on the outside surface before installing.


Thanks all- Looks like oil is coming from the camshaft seal, but what has me concerned is that that seal is brand new, and has been replaced twice within the past month. I can see splashing on the front skid plate, underneath the block on the drivers side (if looking in the engine bay from the outside). Definitely smells like burning oil, and I’m seeing faint smoke come from the same area described above.

When did vehicle manufacturers start using “cam seals” and why do they think that they are better than the old way that they used to install cams? I’ve had a few OHC engines and never lost a drop of oil.

If it’s not the seal, could that mean the camshaft is not true? The vehicle is still under warranty, but of course. only for major repair. In the 5 Subaru’s I’ve owned, I have never had this issue before. If in fact the camshaft is not true, does that entail a new motor?

I read some complaints on pitting of the camshafts, but more than likely it’s installation problem. Here’s a quote from the Subaru forum.
“To you guys who are still leaking after installing new seals : you’re not seating them in all the way, correct? There’s a drainback hole at the bottom of the seal’s bore that cannot be covered! If it is, you’ll have issues with leakage and pressure buildup. The face of the seal should meet up with the inner chamfer radius of the seal bore (i.e. the “bottom” of the bevel), no further.”

Thanks for that knfenimore- appreciate the insight.