I have an '04 Impreza TS. This morning it was 23 degrees in the granite state and I was excelerating from a stand still. Between 2,000 and 3,500 rpm I got a ticking sound from my motor. It sounded like dry lifters but as soon as it warmed up it was fine. I'm running the recommended 5w-30 but is there a better weight for winter or something? Or is this not even a problem at all?

-Chris

Every Subaru I've ever been in clicks (or taps or ticks... however you want to describe it) a little bit in the cold until it warms up. I don't think its anything to worry about unless it doesn't go away once it's warm.

 

Brian M.

That's the much talked about "piston slap".

 

The pistons have been shortened to reduce internal friction, and since all pistons are oval in shape until they heat up, this design will slap/tick/rattle.

 

Nothing to worry about. A lot of Honda engines do this too - even at idle!

 

 

5W-30 is what I am using for winter, and it's working fine in terms of slap. 0W-30 or 0W-40 is even thinner and the slapping can sound slightly violent with those oil types.

 

For summer I run 5W-50.