Flyer
New member
I just took the cover off the top of the timing belt and started the car seems the cam shaft gear has a wobble to it any ideas why car is running ok, could the end of the cam shaft be bent.
cam shaft gear
- Thread starter Flyer
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Powder Hound
Top Post Dawg
- Joined
- Oct 25, 1999
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- Under a Bridge, Crestview, FL, USA
- TDI
- '00 Golf 4dr White 5sp, '02 Jettachero 5sp, Wife's '03 NB Platinum Gray auto(!)
That is a possibility. In what direction is the wobble?
There are a few reasons this could be, mostly relating to one or more ham-fisted mechanics working on the car and bending the cam sprocket, or over-torquing the bolt that holds the cam gear and splitting either the cam gear or the nose of the camshaft. I think either of these are more likely than simply bending the end of the cam itself, with the sprocket caving in the most likely.
Sometimes it is a crap-shoot however. There is at least one instance of a "mechanic" who decided to cut a new woodruff key slot into the cam (IIRC - I forget which one doesn't have a slot) because the other side did, never mind the fact that there wasn't a key that fell out or that the procedure should make it obvious that a key isn't used. My point is that when your car is in the hands of someone else, be it a bad mechanic or former owner, there is no telling what is going to happen to a poor innocent unsuspecting car.
Why is the car running OK: in a condition such as you mentioned, a wobbly cam sprocket would stress one side of the belt then the other. The tensioner located just under that sprocket will keep the belt located because of the sides of the tensioner roller. The tensioner spring will also work to keep the overall tension of the belt under control. However, this condition will compromise the belt and tensioner, and probably most of the other rollers in the loop. The wobble pulls one side of the belt more than the other. This back and forth pulling on the belt is what will cause early failure of the belt and/or other parts.
This is a good time to find someone to fix the car properly so that you will not run into problems later, such as other timing belt items (belt, tensioner, other rollers) failing due to the unresolved stresses from a wobbly cam sprocket. A complete timing belt job should be performed, as well as the item(s) to fix the cam sprocket wobble itself. This will keep you from having the belt fail at some very inopportune time, stranding you somewhere too far from anywhere, and costing much much more money to fix than the bitter pill you have to swallow now.
I wouldn't wet your pants in a panic, but I wouldn't delay this repair, either.
There are a few reasons this could be, mostly relating to one or more ham-fisted mechanics working on the car and bending the cam sprocket, or over-torquing the bolt that holds the cam gear and splitting either the cam gear or the nose of the camshaft. I think either of these are more likely than simply bending the end of the cam itself, with the sprocket caving in the most likely.
Sometimes it is a crap-shoot however. There is at least one instance of a "mechanic" who decided to cut a new woodruff key slot into the cam (IIRC - I forget which one doesn't have a slot) because the other side did, never mind the fact that there wasn't a key that fell out or that the procedure should make it obvious that a key isn't used. My point is that when your car is in the hands of someone else, be it a bad mechanic or former owner, there is no telling what is going to happen to a poor innocent unsuspecting car.
Why is the car running OK: in a condition such as you mentioned, a wobbly cam sprocket would stress one side of the belt then the other. The tensioner located just under that sprocket will keep the belt located because of the sides of the tensioner roller. The tensioner spring will also work to keep the overall tension of the belt under control. However, this condition will compromise the belt and tensioner, and probably most of the other rollers in the loop. The wobble pulls one side of the belt more than the other. This back and forth pulling on the belt is what will cause early failure of the belt and/or other parts.
This is a good time to find someone to fix the car properly so that you will not run into problems later, such as other timing belt items (belt, tensioner, other rollers) failing due to the unresolved stresses from a wobbly cam sprocket. A complete timing belt job should be performed, as well as the item(s) to fix the cam sprocket wobble itself. This will keep you from having the belt fail at some very inopportune time, stranding you somewhere too far from anywhere, and costing much much more money to fix than the bitter pill you have to swallow now.
I wouldn't wet your pants in a panic, but I wouldn't delay this repair, either.
manual_tranny
Smyth Performance- Intern
Well said, powder hound.
Why did you take off the timing belt cover in the first place... routine maintenance? I'm just curious if it is making any unusual noises or if you decided to peek under there for the heck of it.
I doubt the camshaft itself is bent... but it could be damaged. Either it is scored away, dented, or chipped... or the pulley is scored/dented/chipped. I believe it is quite robust where the pulley attaches. Perhaps a hammer was used to remove the camshaft pully with the bolt on or partially on? I imagine this could cause some metal to dent/bend or chip causing your wobble.
Why did you take off the timing belt cover in the first place... routine maintenance? I'm just curious if it is making any unusual noises or if you decided to peek under there for the heck of it.
I doubt the camshaft itself is bent... but it could be damaged. Either it is scored away, dented, or chipped... or the pulley is scored/dented/chipped. I believe it is quite robust where the pulley attaches. Perhaps a hammer was used to remove the camshaft pully with the bolt on or partially on? I imagine this could cause some metal to dent/bend or chip causing your wobble.