I have a 2010 Subaru Outback that is making a sound that sounds like glass bottles clinking. It occurs when accelerating around 20mph and/or around 40 mph. Can really hear it when there is a load like going up a hill at these slow spends. Dealership did a lot of flushing and lubricating and new filters etc, but that wasn’t it. Also replaced my heat shield (yikes$) but that wasn’t it. Then they had me run a tank of 93 octane and they didn’t fix, so put in a bottle of engine cleaner and it didn’t work either. Have spent close to 1k on “guess work” and still have the noise. Any ideas? Thanks.
Different people describe the same noise in different ways, but–given the circumstances under which you hear the noise–it is very possible that the engine is “pinging” under load. While I would describe “pinging” as the sound of pebbles being shaken inside a tin can, I suppose that glass bottles clinking together could also be a valid description of the noise of “pinging”.
Because that type of situation is going to damage your valves and pistons if it is not corrected, it is important to get it resolved. Possible causes include a gunked-up EGR system and a defective engine knock detector. Since the warranty is no longer in effect on your car, and since the dealer hasn’t been able to resolve the problem, I would suggest that you take the car to a well-reputed independent mechanic.
I’d Ask For An Appointment To Meet With The Subaru District Service Representative With Your Car And Express Your Dissatisfaction With The Performance Of The Car And The Dealer And Your Frustration With The Expense.
They “don’t all do that.”
Also, Subaru Customer Relations may be willing to help you.
Do You Know If The Engine Computer Was Ever Reprogrammed? There Are A Few Subaru Revisions For 2010 Outback ECM (engine control module) Reprogramming Files. Bulletins Accessed By Dealers Explain These.
These revisions are made to address problems with drivability concerns like a decrease in RPM during low speeds with the AC on, etcetera. I’m not saying that this would solve your problem, but I have to wonder if the dealer has considered an “engine control” (software) problem, besides just going after “mechanical” issues?
Again, a Zone Service Rep should be more informed in these matters and/or have easier access to obtaining ideas from Subaru.
+1 to VDC’s post.
Finally got to a recommended mechanic. They heard it with certainty and had no trouble duplicating but were puzzled by it. They said they did some research and they believe it is piston slap. However, I am researching and finding that everyone says piston slap goes away when engine is warm. My glass bottle noise/clank doesn’t go away. I can drive hours and as soon as I get back down to 20mph or around 40 mph, it’s still there. Does piston slap diminish with warm up? If it is piston slap, what can be done ( not getting a new engine). Thanks for any help.
Is the noise present with the vehicle stationary and while revving the engine? If the noise is not present then I tend to agree with VDCdriver about pinging and the likely cause being an EGR or knock sensor fault.
Are there any subtle ticking sounds with the engine at idle and with the hood up for purposes of clarity?
I would not get too wrapped up in a piston slap diagnosis at this point and especially a diagnosis that appeared to come from online fishing. That’s the way I take the comment, right or wrong, about “did some research”.
A good mechanic can instantly tell if the sound is “spark knock” or “pinging” so I wonder what kind of “mechanics” work at the dealership? This should not be rocket science but apparently those dealership mechanics think that it is. I shake my head.