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).