Questionquestion. Ive done numerous timing belts all makes and models.
I installed the timing belt as well ass BS belt. the oil pump has a guide on the out side to keep the belt inline like the balancer shaft. to get to the point after i had all timing marks dead on tensioner pulled correctly. i always like to to start it for a second as a sure proof check i know timing is correct. i didnt put the crank bolt in when i started it only for max 2 seconds. with the belt tight i figgured the guide on the oil pump was enough to get keep the belt on. well i\the crank sprocked pushed put instatlty and im sure you know what happened next. on several jobs ive done ive always sone them that way. Even interference motors like this one. i just dont know why the belt shot out that fast. it was the 2.4l ive done probably 4 or 5 of the v6 sante fa the same way. even though i dont think they a bs belt and and oil pump timing mark like v4. i know i should if tightened the crank bolt to lock it in place. i quess im asking if did that because of my iggnorance by not tightening crank bolt. i just dont understand why the belt slipped forward when only ran for 2 seconds. so now i have to replace 8 valves the #4piston.
i checked all possible flaws before cranking up the belt was level on all sides dohc, Op, and crank-idlers pulleys. i was hopping to hear bad hydraulic tensioner(was new) or some other reason other than my own fault. i will never do that again, i been a mechanic for 10 years first major mess up like this.
im sure it was my mistake but i like to get an opinnion.
-thanks phil
AnswerHi, Phil. The reason this happened is that without the crank bolt in place, the crank sprocket will walk off because there's nothing holding it in place. Once the sprocket is far enough off to clear the Woodruff key, the crankshaft continues to turn, but the timing belt and camshafts will stop turning.
About 15 years ago, I made a similar mistake. I was working on a car with a similar engine making a noise that sounded like it was coming from the timing belt area. I took the covers off and restarted the engine to make sure. Unfortunately, I forgot to reinstall the crank pulley. As I got back to the engine, I saw the crank sprocket walking off the crankshaft. Before I could even move to turn the engine off, I saw it stop turning and heard the crunch from the engine. In addition to the failed auto tensioner that caused the noise, it now needed a cylinder head and valves.
Sorry about your mishap. Just be sure to fix it right. Everyone makes mistakes; the real test is how we deal with them.
