Timing chain may have slipped some teeth, how can I fix this
#1
Timing chain may have slipped some teeth, how can I fix this
Was chaning the timing chain tensioners, and noticed my guide rails were just disintegrated, nothing but slack in the chain, did not have it at tdc cuz i wasnt planning on replacing the chains, so when i went to put the new guide rails and tensioner on, i noticed the camsprocket moved some teeth. How do I fix this? The engine will not move to TDC now.
#2
why wont the engine rotate ? Look for the timing marks on the crank and cam.... count how many teeth the crank has rotated past the alignment spot... count how many teeth the cam has move... rotate the cam forward or back a few teeth as needed, then install the chain ........ then slowly rotate the engine around by hand until the marks come together and check for final timing.
#3
You should have looked at the procedure involving this before taking anything apart.
A valve is hitting it's piston on one or more cylinders preventing rotation.
Now the cams have to be removed from the heads so the valves set on their seats and do not hit piston crowns.
The rotate crank to top dead center.
Set each cam into place and use a special tool to hold them there.
Install chains and cam drive gears by their chain link indicators.
Get copy of Haynes Manual and look at chapter 2B from pages 4 on, about this procedure.
Good luck.
A valve is hitting it's piston on one or more cylinders preventing rotation.
Now the cams have to be removed from the heads so the valves set on their seats and do not hit piston crowns.
The rotate crank to top dead center.
Set each cam into place and use a special tool to hold them there.
Install chains and cam drive gears by their chain link indicators.
Get copy of Haynes Manual and look at chapter 2B from pages 4 on, about this procedure.
Good luck.
#4
Steve, that worked great. It skipped roughly 4 teeth. Luckily i had pics of how it looked before i started. That was a good starting point. Now moves freely. I have it at TDC and the timing marks on the sprockets are ( facing the engine) L/H 12 oclock and R/H 11 oclock and engine definitely moves nicely. Thanks for the advice. (Keep in mind i never unchained or moved the chain on the right because it never slipped) It all worked out. Thanks. Lesson learned. Next time ill definitely use the camshaft securing tools.
#5
I'm glad I read this post. Recently acquired a 2002 F150, 4.6 that the chain guide disintegrated. Chain bound around the crank, effectively locking the motor in place. The guy I got the truck from "attempted" to correct the chain issue, but afterwards, could not get the motor to rotate. I will check the things mentioned above to see how bad it actually is.
#6
#7
Bass, like Steve mentioned, mine just skipped a couple of teeth, but these engines are interference fit, if that chain snapped while the engine was running, there is a good possibly you have some bent valves from smacking the pistons. Mine happened statically without the engine running, and i had pics of the sprockets before i started, thats really the only thing that helped me. Look at bluegrass's post prior. You may have to take the heads off and check your valves. Good luck.
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#8
Steve and Mike
Thanks for the input. I have another motor to replace it, but, trying to see if it would be repairable without pulling the motor. I will see about pulling the heads tomorrow when I get home. The passenger side chain is the one that caused all the problems. I'm guessing it wouldn't be that much more trouble to pull the passenger side head before pulling the motor.
Thanks for the input. I have another motor to replace it, but, trying to see if it would be repairable without pulling the motor. I will see about pulling the heads tomorrow when I get home. The passenger side chain is the one that caused all the problems. I'm guessing it wouldn't be that much more trouble to pull the passenger side head before pulling the motor.
#9
Join Date: Jun 2009
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Steve and Mike
Thanks for the input. I have another motor to replace it, but, trying to see if it would be repairable without pulling the motor. I will see about pulling the heads tomorrow when I get home. The passenger side chain is the one that caused all the problems. I'm guessing it wouldn't be that much more trouble to pull the passenger side head before pulling the motor.
Thanks for the input. I have another motor to replace it, but, trying to see if it would be repairable without pulling the motor. I will see about pulling the heads tomorrow when I get home. The passenger side chain is the one that caused all the problems. I'm guessing it wouldn't be that much more trouble to pull the passenger side head before pulling the motor.
#10
#11
You should have looked at the procedure involving this before taking anything apart. A valve is hitting it's piston on one or more cylinders preventing rotation. Now the cams have to be removed from the heads so the valves set on their seats and do not hit piston crowns. The rotate crank to top dead center. Set each cam into place and use a special tool to hold them there. Install chains and cam drive gears by their chain link indicators. Get copy of Haynes Manual and look at chapter 2B from pages 4 on, about this procedure. Good luck.
Since the passenger side is the one that came apart on mine, do I need to pull both cams, or just that one?
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#15
Hey Steve, im all done, i think it runs great, however, at idle it sounds like its missing. Can being off one tooth cause this? I have power, & it runs fine. Im not kickin a misfire code? Im going to pull all the plugs and make sure there at the proper gap. I shouldve made sure before i put them back in. I read all the primary and secondary resistances on all the coil packs before i put them back in. They were all between at least 5.5 to 6.5. I like them at 5.5, but usually when the packs are bad, its a runaway noticable resistance. It only misfires about once every 10 secs or so at idle. Im praying its a plug. Any input about the tooth off?