Author Topic: cam pulley wobble  (Read 5158 times)

May 22, 2009, 01:33:45 pm

juleshs

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cam pulley wobble
« on: May 22, 2009, 01:33:45 pm »
i have noticed that my cam pulley runs like a buckled wheel on a push bike and there is a tappet noise could this be just the pulley or more likely a bent cam (1.9td aaz)  its a recon head everything in it is new cept the cam

Reply #1May 23, 2009, 03:11:35 am

88jetta350

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Re: cam pulley wobble
« Reply #1 on: May 23, 2009, 03:11:35 am »
Best thing to do would be to inspect both the cam and the pulley, if in doubt, swap it out.

Reply #2May 23, 2009, 07:57:57 am

juleshs

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Re: cam pulley wobble
« Reply #2 on: May 23, 2009, 07:57:57 am »
could a bent cam cause it to sound tappety

Reply #3May 23, 2009, 10:52:31 am

Rabbit on Roids

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Re: cam pulley wobble
« Reply #3 on: May 23, 2009, 10:52:31 am »
BENT cam? how do you manage to bend hardened steel?
has anyone ever managed to drop a cam shaft?
they explode... end of story. ask me how i know?
but anyway, i definitely would look into fixing that.
if the cam is bent, the seal should be leaking like a mofo.
there isnt much cam to bend between the first cam bearing and the sprocket.

Reply #4May 24, 2009, 02:35:55 pm

88jetta350

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Re: cam pulley wobble
« Reply #4 on: May 24, 2009, 02:35:55 pm »
BENT cam? how do you manage to bend hardened steel?

By loosening the cam bearing caps incorrectly, It is possible to warp the cam, but unlikely.

I would check out the sprocket. Sounds to me like the tapered hole in the center of the sprocket is out of round, or the nose of the cam is worn somehow. Something is out of spec.

Did you check the bolt on the sprocket, make sure it's tight, remember that these engines don't have a keyed cam sprocket, so if that bolt comes loose, your cam sprocket will free-spin, and then game over. :(

Reply #5May 24, 2009, 02:43:34 pm

Rabbit on Roids

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Re: cam pulley wobble
« Reply #5 on: May 24, 2009, 02:43:34 pm »
dont have a key way? WHAT?
when i pulled the sprocket off my 1.5 head, a little key fell out too.
and there are definitely key ways in the cam and sprocket.
but just because they are there doesnt mean i use them.
but yes, there are definitely key ways on these engines.
my MF 1.6 TD has key ways too. is this an AAZ only type of thing?

Reply #6May 24, 2009, 04:03:55 pm

Jettagli16v

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Re: cam pulley wobble
« Reply #6 on: May 24, 2009, 04:03:55 pm »
1985 MF code, bone stock.
No key at all on camshaft pulley:
It is a tapered end and a press fit into a smooth taper in the pulley.
Remember, on a Diesel you have the cam lock tool, when changing T-Belt so the location of the pulley is irrelevant and should be based off the interaction between crank and IP.

i think,
-Brad
Currently: 81 Caddy 1.9 AAZ, 1995 Audi S6, 78 ASI/Riviera camper bus 2.0, 74 THING 1.8 (resto, coming in 2020).

Reply #7May 24, 2009, 04:44:37 pm

Rabbit on Roids

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Re: cam pulley wobble
« Reply #7 on: May 24, 2009, 04:44:37 pm »
there are actually cam timing marks on the cam sprocket.
and idk why no one else has key ways on their engines.
mines an 84 MF code engine, out of a jetta. the key ways and timing marks actually all line up too when you have it set up right.

Reply #8May 24, 2009, 06:05:57 pm

Vincent Waldon

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Re: cam pulley wobble
« Reply #8 on: May 24, 2009, 06:05:57 pm »
There are keyways on any 1.6 and 1.9 IDI cam shaft I've ever seen, yup, must be a manufacturing left-over, but no key... nor should one be used.  Setting the cam timing safely involves much more precision than a key would allow.
Vince

Edmonton, Alberta, Canada
2001 silver TDI Jetta Malone Stage 1.5 , 2001 blue TDI Jetta SBIII 216s Malone Stage 3, 1970 Bay Window bus

Gone but not forgotten: 1969/1971 Beetles, 1969/1974 Westies, 1979 Rabbit, 1986 TD Jetta, 1992 gas Jetta, 1994 TD Jetta

Reply #9May 25, 2009, 01:45:21 am

Rabbit on Roids

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Re: cam pulley wobble
« Reply #9 on: May 25, 2009, 01:45:21 am »
maybe i just have a spectacular matched head setup then. my key fits in the key ways properly, and the cam still times spot on. is this random? the last people to work on my engine besides me, were the people at VW who built it. so i know that key wasnt there on accident?

Reply #10May 25, 2009, 08:47:01 am

Rabbit on Roids

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Re: cam pulley wobble
« Reply #10 on: May 25, 2009, 08:47:01 am »
wow, thats really weird. but my engine does still have the same head gasket it came from the factory with. and i put the head back down on the SAME SPOT on the head gasket. since it was a used gasket, it had some indentations on it, and it actually helped center the head. im not going to say cam timing was SUPER PERFECT, but it was close enough for me. so i timed it all, set the key in there, slid the sprocket on, and it actually lined up with the key. i honestly didnt think that they used a key either, but this engine has one. it has a key way on the crank too. and the crank pulley has a key. this isnt the same setup as my 1.6 has. it has the normal 1.6 style crank. maybe my 1.5 is just soo ancient that it has all the extremely old manufacturing processes that VW used? this engine did come out of a 76 rabbit BTW.