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dalail4m3r

740 not starting after timing belt change

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Hello fellow petrolheads. I drive a 740 from '88 with the b230f engine.

I changed the timing belt with a friend of mine. Afterwards I tried to start the engine twice which didn't work. I've never heard a sound like this before, like the engine was trying to turn but couldn't. After checking every step we noticed that the crankshaft bolt wasn't tightened properly. We used only 60nm(44lb ft), although it needs another 60 degrees of turning. Bodged it. Well, the engine is non-interference, but I don't know if this caused any damage.

As I'm 23 and only mildly experienced, I greatly appreciate any help on how to proceed. I really do like my car

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On 3/8/2017 at 8:08 AM, dalail4m3r said:

Hello fellow petrolheads. I drive a 740 from '88 with the b230f engine.

I changed the timing belt with a friend of mine. Afterwards I tried to start the engine twice which didn't work. I've never heard a sound like this before, like the engine was trying to turn but couldn't. After checking every step we noticed that the crankshaft bolt wasn't tightened properly. We used only 60nm(44lb ft), although it needs another 60 degrees of turning. Bodged it. Well, the engine is non-interference, but I don't know if this caused any damage.

As I'm 23 and only mildly experienced, I greatly appreciate any help on how to proceed. I really do like my car

What do you mean that you noticed the crankshaft bolt wasn't tightened properly? And that really only affects the accessory belt pulley, right? Timing marks were still lined up afterwards? I doubt this was a problem. Only might have become an issue if the bolt backed out on your later on and the pulley came off. You left the camshaft's gear on, right?

Can you crank the engine by hand? Put a wrench on the crank bolt and spin slowly. Make sure your ignition is off. You should feel some resistance for each piston's compression as you work your way around. Loop it twice, then double check your timing marks.

Is it possible you just killed the battery from using interior lights or something benign?

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