Prior to a 3000 mile trip I took my '01 outback to the nearest Subie dealer who happens to be 140 miles from home.
They gave the engine, 2.5 with 65K miles, a clean bill of health. I mentioned a tapping noise on cold start even in hot weather. The service writer asked whether it disappeared after warm-up, I confirmed that it did.
He called it "fuel injector pulse" and not to worry.
I'm a noobie on this group. I would appreciate your thoughts.
Probably a 'BS' answer. More likely piston slap - less likely timing belt tensioner.(I think this is on cars older that your model though - anyone?)
Carl
Fuel injector pulse? Noisy injectors don't normally quiet down as the engine warms up, and it's rare for a single injector to be so loud you'd be aware of it. Personally, I've never noticed injector clicks above the other engine sounds.
I agree that piston slap on so low a mileage engine is unusual, and that it is as audible in warm weather as in cold reinforces that a bit. I'm thinking exhaust leak (usually caused by a broken exhaust manifold stud). Exhaust leak "tapping" usually goes away more quickly than piston slap, too - usually within a minute as opposed to several minutes for piston slap.
A quick survey of all the exhaust manifold studs with your fingertips (I recommend a cold engine!) will tell the story on that, but realistically, what do you intend to do if you find a broken stud or slapping piston? The most practical remedy for either of those is to turn Bon Jovi up a bit the first few minutes after you start the cold engine
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