Well, a reader Q.
Christine asks:
The other day my car started making a noise like an aerosol can being sprayed. It lasted for a couple of minutes and than stopped. The car seemed to be running okay.
My Answer:
That brief rattling sound was likely what’s called “engine ping” or engine knock – pre-ignition or detonation, in more technical lingo. Basically, the explosion in a cylinder(s) happened prematurely, before it should. This usually happens because of lower octane fuel igniting before it’s supposed to. In a modern car, there are knock sensors that detect this and the computer adjusts the engine (timing) to compensate. If it only happened briefly and went away, I would not worry. Be sure you are using the correct octane rating fuel for your vehicle; it should tell you on the gas cap/door or in the owner’s manual.
Another possibility is that the engine “lugged” briefly. This happens most often in a car with a manual transmission, when you are in too high a gear for the vehicle speed; downshifting to a lower gear is the fix in that case.
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Hey Eric, Thought you would find this interesting (if you haven’t seen this before). The Audi A8 is bucking the aluminum trend, and is going back to more steel.
http://www.nwitimes.com/business/local/audi-a-switching-back-to-high-strength-steel/article_e9195036-b087-5986-9956-34af8b0bbf86.html
Smart… I am glad to hear it…
Aerosol cans don’t rattle when sprayed.