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![Anon](/assets/aa/aa-avatar.png?m=1466990309)
I have a 1989 corolla, when driving up hill I have to drop gears as the engine rattles like crazy. I changed the spark plugs which helped a bit but still rattles - is this a sign of oil leaking into the engine
Colm
From the "Ask Jack" archives - 14 December 2009
![jbiddle](themes/aaAle/images/interface/profile-pic-placeholder.47cf740a.png)
Sounds to me like the engine is 'pinking'. This can happen if the Octane rating of the fuel is too low.
If you are currently using regular 91, then make a change to Premium 95 which is the recommend fuel for this vehicle, and see if the rattle stops.
If it persists, then it's into the garage for a tune up, or a check to find the cause.