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sometimes-pilot

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  1. Thanks... the timing belt definitely slipped a tooth at some point. One mistake I made is that 15 degrees of rotation at the crank ends up being only 7-1/2 degrees error where it counts...at the camshaft end, because the camshaft rotates at half the speed of the crank. i slipped a rod down the spark plug hole to make sure the crank TDC timing mark was correct (it was, but i wanted to verify). using a punch through the sprocket hole to the exhaust cam bearing satisfied me that it was off only one tooth, ergo 7-1/2 degrees. i'm not the brightest at this stuff, so tonight i was counting cam sprocket teeth and got 48. 360 degrees divided by 48 = 7-1/2 degrees. 7-1/2 degrees of error at the cam gives me a little better feeling that it is unlikely (if it ever was possible) that something got bent inside. thanks for the help...sure wish i knew about this site a while ago. regards, steve rineer
  2. my daughter overheated her Geo (sorry, not a corolla) which has the 4AFE engine, and the cylinder head is too far gone to machine, so I got a used engine, 77,000 mi, out of a salvage yard. good time to replace the timing belt & water pump, so the engine is on my garage floor before installing them. however, when i rolled the crank over to tdc the camshaft TDC timing marks weren't where I thought they're supposed to be...meeting on a horizontal plane ( i think i'm right but am willing to be corrected). if i line up the camshaft TDC timing, the crankshaft timing mark shows 15 degrees after TDC; put anothe way, i believe cam timing is 15 degrees before where it should be. i talked with a mechanic who suggested maybe the belt slipped a tooth, but said performance would be obviously much poorer. so here's my questions: it's a non-interference engine, so i am presuming that valve timing which is off 15 degree will not have the valves & pistons coming together, and therefore that's no consequence. next: is there any possibility that a DPO would have knowingly advanced the valve timing to get some performance advantage. am i correct about the camshaft timing marks should be in horizontal alinement at TDC (looking through the exhaust camshaft hole, the timing mark on the #1 exhaust bearing lines up correctly at this point). TIA, Steve Rineer
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