Why do Subaru engines knock?
Detonation Knock Most commonly, this is caused by using fuel with an insufficient octane rating for your car. If your vehicle requires premium fuel (such as a turbocharged Subaru WRX), this kind of knock can be caused by accidentally filling up the vehicle with regular grade fuel.
What does engine knock sound like?
An engine knocking sound is frequently described as a metallic pinging noise that resembles the noise made by metal balls being shaken in a tin can. During light acceleration, or when going up hill, it is normal for some engines to exhibit a slight engine knock noise.
Why does my Outback Outback make a rattling noise?
I noticed a rattling noise (like marbles) coming from the engine upon startup in the morning only. The noise goes away after a few seconds. To me, it sounds like bearings rattling due to low oil pressure, but the dealer says that every Outback and Legacy does this. It has a timing chain, and the engines use 0-20 synthetic oil. Is this normal.”
Is the noise from the Subaru engine harmful?
The noise is not harmful to the engine or exhaust system. It’s important to note that during normal driving this mapping is ignored. We think given Subaru’s explanation, Johnznot having had a dealer start three random new Outbacks on the lot, and our experience with this type of sound, it is fair to say “They all do that.”
What does the new Subaru Outback engine sound like?
Next, I wondered if the new Outback had switched to direct fuel injection. Direct injection is noisy and can sound like anything from a loud static hiss to a close approximation of the sound a diesel engine makes. Nope. No direct injection yet in the Subie 2.5i.
Why does my Subaru make a distinct sound when I start the car?
Subaru offered the following explanation for the distinct sound that may give some folks cause for concern. Subaru says: The new engines, especially the four-cylinders, are extremely efficient so they have very low friction. Because of that, this process assists the engine behavior at start up to help them warm up.