As I bent the valves on my friend's car for the second time in a week I need help. I've already talked to somebody described by my Ford-contacts as "The Finnish Zetec Guru" and he couldn't help me on the phone.
So, last weekend I changed the timing belt on my friend's 2004 Ford Focus 1.6 16v. All went well, the engine ran ok-ish after the belt change. I pushed the throttle and at 5000rpm the engine jammed. Turned out the crankshaft pulley bolt came out, which stopped the belt and thus the pistons hit the valves. During the week the head was repaired by a machine shop, replacing all 16 valves and taking 500€ of my friend's money. Today I put it all back together. We spun it over on the starter motor with the ignition coil disconnected for about a minute to build up oil pressure and all seemed well, the engine rotated freely. I connected the ignition coil, we tried to start it, it ran for about 2 seconds before the engine once again jammed. Crankshaft pulley bolt came loose again
So some details about what I did for those who think they may have something to say on this:
- There is a sprocket on the crankshaft that drives the timing belt, on top of that there is a pulley for the alternator drive belt, and the whole thing is held by one bolt in the center. The axle is not cone shaped and the pulleys rotate freely without the bolt.
- When we originally tried to remove the crankshaft pulley bolt it was so tight our sturdy impact gun on a 10 bar compressor could not open it. I opted to use the starter motor, which was slightly dangerous given that the pulley rotates freely on the crank as soon as the bolt is out. It worked though.
- When I put the crankshaft pulley bolt in the first time I was a bit fuzzy about the torque, so I'm willing to believe I didn't tighten it enough that time.
- I'm 120% sure I put it on the correct 40Nm + 90 degrees today. I had the car in first gear, my friend pushing the brake, and a screwdriver leaning on a piston through a spark plug hole to double check that the engine did not rotate while I made the 90 degree turn with a longer lever.
- The thread in the crankshaft seems fine. There is no visible damage and the bolt goes in and out easily, and felt good while tightening. There is also no visible damage to the outside of the crankshaft, and I made double sure it was clean today.
- I used a new bolt both times. First the one that came with the belt, then one bought from a Ford dealership. These come in two lengths, this car had the shorter one fitted (29mm long shaft with 26mm long thread). The bolts did not get visibly damaged.
- We got the timing close enough to correct both times.
When you slide the sprocket and the pulley on the crankshaft the whole package is extending noticeably over the end of the crankshaft. It should also be like that to allow the bolt to tighten the whole package together, but is it possible that the pulley or sprocket is simply to wide for its tolerances?
I'm in the dark here, and I feel really bad about it as it is my friends car.
So, last weekend I changed the timing belt on my friend's 2004 Ford Focus 1.6 16v. All went well, the engine ran ok-ish after the belt change. I pushed the throttle and at 5000rpm the engine jammed. Turned out the crankshaft pulley bolt came out, which stopped the belt and thus the pistons hit the valves. During the week the head was repaired by a machine shop, replacing all 16 valves and taking 500€ of my friend's money. Today I put it all back together. We spun it over on the starter motor with the ignition coil disconnected for about a minute to build up oil pressure and all seemed well, the engine rotated freely. I connected the ignition coil, we tried to start it, it ran for about 2 seconds before the engine once again jammed. Crankshaft pulley bolt came loose again
So some details about what I did for those who think they may have something to say on this:
- There is a sprocket on the crankshaft that drives the timing belt, on top of that there is a pulley for the alternator drive belt, and the whole thing is held by one bolt in the center. The axle is not cone shaped and the pulleys rotate freely without the bolt.
- When we originally tried to remove the crankshaft pulley bolt it was so tight our sturdy impact gun on a 10 bar compressor could not open it. I opted to use the starter motor, which was slightly dangerous given that the pulley rotates freely on the crank as soon as the bolt is out. It worked though.
- When I put the crankshaft pulley bolt in the first time I was a bit fuzzy about the torque, so I'm willing to believe I didn't tighten it enough that time.
- I'm 120% sure I put it on the correct 40Nm + 90 degrees today. I had the car in first gear, my friend pushing the brake, and a screwdriver leaning on a piston through a spark plug hole to double check that the engine did not rotate while I made the 90 degree turn with a longer lever.
- The thread in the crankshaft seems fine. There is no visible damage and the bolt goes in and out easily, and felt good while tightening. There is also no visible damage to the outside of the crankshaft, and I made double sure it was clean today.
- I used a new bolt both times. First the one that came with the belt, then one bought from a Ford dealership. These come in two lengths, this car had the shorter one fitted (29mm long shaft with 26mm long thread). The bolts did not get visibly damaged.
- We got the timing close enough to correct both times.
When you slide the sprocket and the pulley on the crankshaft the whole package is extending noticeably over the end of the crankshaft. It should also be like that to allow the bolt to tighten the whole package together, but is it possible that the pulley or sprocket is simply to wide for its tolerances?
I'm in the dark here, and I feel really bad about it as it is my friends car.
