Belt flipped and weird sound

To start off I will flippantly comment that I need a new nickname:
Dumb Kid. Now that you're in the proper frame of mind, let me
continue.

I'm still hard at work with my '72 Super. I've tackled a few more
things by now. I'm almost there. One thing I had to deal with was I
needed a completely new set of engine tin, because the engine in mine
came out of a baja that I also bought. I got the Baja first, but
didn't like it. So I bought the '72 from a guy who agreed to a low
price if I would take the engine out and return it to him.

So now you know why I needed new tin. I didn't even really know what
tin pieces I needed or how they "should" fit. I did put all the tin on
now although it was a tedious job and I had to back up a few times and
start over when I realized a piece had to preceed another piece. I'm
going to try to explain what I've done and what I now see and provide
info so you can help but it's hard to get the info in here without
rambling but I will try.

So I got it all back on and I got my carb to stop leaking (new
accelerator pump diaphram) and I notice a couple of weird noises. One
is a loud click sound that happens upon fast acceleration and it really
has me worried but I'm going to save that for another post. The second
sound is a vibration type sound. Like a buzz that happens for a second
at certain RPM's. It's also quite loud but seems more innocuous than
the click. The buzz is what I am going to focus on in this post.

Basically in order to get the tin on I had to remove about everything
from the engine -- the carb, alternator, shroud (the only original tin
I did have), intake manifold, exhaust. I put the new tin on and it's
all fully bolted down. I used 10mm hex head bolts all around and I used
lock washers to try to prevent losing a bolt and the tin that it
supports. Everything is down tight and I doubt there is a problem of
loose tin bolts.

At one point I removed the crank pulley bolt because I thought it was
the only way to get the pulley tin behind the crank pulley. I tried to
carefully pry the pulley off but I didn't want to screw it up so when
it didn't come easy I put the bolt back on and just kept working the
angles. I finally got the tin on. At one point I had every bit of tin
all on but when I cranked the engine over there was a bad squeel. I
figured out it was the fan rubbing inside the shroud. So I broke
things back down and checked the fan. It seemed to wobble just a bit
but would not normally bind. So when the alternator was clamped down
it would pull on the shroud and cause it to bind. So I figured out
that my shroud was not sitting down quite all the way. After fumbling
about with the contact areas between the shroud tin and the case and
the cylinder tins, I was able to get it to seat down good and the
alternator bolted down and the fan no longer rubs. Whew. So again I
put it all together. Started up fine this time with no odd noises.

However, I noticed after a couple of revs there is this bad vibration
sound at about 2000 rpm. So I go back to the rear and pull the
throttle and try to isolate. I couldn't figure it out. I grabbed a
bunch of things that were away from the belt area to see if the sound
would go away. I even grabbed the coil, and then remembered that you
SHOULD NOT grab the coil. Boy that was fun. I noticed that as I
pulled the throttle the belt would get kind of eccentric (like wobble
or flip or whatever in it's track, as if loose). So I decided maybe I
didn't tighten the crank pulley enough when I put it back on. I was at
this point getting impatient so instead of going off to read I reasoned
that it should be pretty tight, like as tight as the gland nut on the
opposite side. I tightened it down about as tight as I could with an
extension. I hope that was ok. Right at the end it seemed to slip a
little so me being scared to death I just stopped and figured it was
either tight enough or it was hosed. Either way not much I could do.

Repeat test. Belt seemed to flow a little better, noise seemed a
little less. So I decided to try to tighten the belt. I removed the
alternator pulley, moved two shims from the inside to outside, and
retighted. I went back to the driver's seat and tested where I could
see my tach. At first, the sound was the same, and was at about 2000
rpm. But I noticed as I moved up the rpm scale it would happen again a
couple times (as if at a harmonic further up). After revving it a bit
and playing with it the noise all but went away. The only way I could
coax it out was to accelerate fast to 2000 and then release right as
the tach needle want past the 2000 mark, then on the deceleration it
would make the noise for a second.

It was getting late so I went in to watch Star Wars with my wife.

Next morning, renewed, I went back out and put in the two screws I
realized I had forgotten on the bottom of the alternator shroud to fan
shroud housing. It was a pain becuase these two screws are low and
behind the intake manifold once everything is in right. I did get them
in though with the help of my wife's small hands. Test. Still the
noise. Damn. All night sleeping on it and that was the best I could
do and it didn't work. Waste of a night's sleep if you ask me.

So wanting to get my wife in a better mood I say "get in and we'll go
for a ride". It's not yet legal (I'm workin' on it) so I just back up
on the lawn and forth again a few times. There that was our ride.
Aren't you glad I bought this car????

My wife was feeling a little better and went in. I was feeling worse
of course because I still don't know what's going on. So I went back
and popped the deck lid. I notice that the belt had flipped during our
little "excursion". I had revved it a few times, up to about 4000 as I
went back and forth on the lawn. The belt flipped during this and was
now tracking kind of upside down on the wrong side (the goodyear brand
name letters on the belt invisible).

So guys my belt is pretty tight. I am pretty sure I understand the
"half inch play" setting. You should be able to press on one side of
the belt and get about a half inch deflection without pressing super
hard. If anything I'd guess mine is a little tight.

However, I can tell you that when I accelerate rapidly the belt kind of
goes haywire for a second. I am not really sure if that has anything
to do with the vibration sound, but visually it seems the sound happens
the same time as the belt is wobbling. I also can't pin point the
source of the sound. It sounds as though it could be the tin
vibrating. But perhaps it could be a bearing gone bad too. I'm not
really that experienced with identifying sounds like this. It is
coming from the area near the pully/belt area. If I press with a
screwdriver on the tin where I would assume it could vibrate it doesn't
seem to alleviate it, nor do I feel a super strong vibration as if I
found the source.

My biggest concern right now is the belt because it wigs out and
because it flipped on me. Do you think it is still too loose? Or did
it flip because I have it too tight??

I'm just a Dumb Kid and I don't know. I'm still learning about
everything. I will screw up a lot more I'm sure of it. I hope
although this was long I was able to spice it up a bit. I just wanted
to make sure you know what I know so you have something to go on.

TIA.

Chronologic

Chronologic wrote:


> So guys my belt is pretty tight. I am pretty sure I understand the
> "half inch play" setting. You should be able to press on one side of
> the belt and get about a half inch deflection without pressing super
> hard. If anything I'd guess mine is a little tight.
>
> However, I can tell you that when I accelerate rapidly the belt kind of
> goes haywire for a second. I am not really sure if that has anything
> to do with the vibration sound, but visually it seems the sound happens
> the same time as the belt is wobbling. I also can't pin point the
> source of the sound. It sounds as though it could be the tin
> vibrating. But perhaps it could be a bearing gone bad too. I'm not
> really that experienced with identifying sounds like this. It is
> coming from the area near the pully/belt area. If I press with a
> screwdriver on the tin where I would assume it could vibrate it doesn't
> seem to alleviate it, nor do I feel a super strong vibration as if I
> found the source.
>
> My biggest concern right now is the belt because it wigs out and
> because it flipped on me. Do you think it is still too loose? Or did
> it flip because I have it too tight??
>
> I'm just a Dumb Kid and I don't know. I'm still learning about
> everything. I will screw up a lot more I'm sure of it. I hope
> although this was long I was able to spice it up a bit. I just wanted
> to make sure you know what I know so you have something to go on.
>
> TIA.
>
> Chronologic
>



The pulleys aren't lined up with each other. One sits further out than
the other. Very common problem when you have mis-matched parts or
aftermarket parts. The top pulley is easier to work with, you can add a
spacer behind it for example. The dimensions (depth) vary between
different top pulleys, the aftermarket one is often "wrong" for your
application and needs to be spaced or (my rec) thrown away.
They do happen to line up nicely sometrimes with aftermarket -equally
crappy and out of spec- lower pulleys. Good luck.

Jan

Jan

belt flipped:

too tight probably.

sound could be coming from alternator.

remove the belt, and fire up your vehicle.
run it through your tests.

noise still there?

what kind of noise? can you record it and
put it on the internet?

is it high frequency or low frequency?
if it is low frequency, can you tell us the frequency?
IE, 10 times a second.

is it high pitch? low pitch? a bang? a knock?
a tap?

Do you have your exhaust mounted nice and
tight?

with engine running, use a long screwdriver and
press the driver end to the engine. Press
the handle to your ear. It works good for trying
to find the source of strange sounds.


PS careful with hex bolts holding tin. Use a
torque wrench, or you will start stripping out
your case.

Jan,

That sounds very likely and is a good thought. Since I have been
screwing around with the alternator maybe I just bolted it down a
little too far forward or aft. I think all the pulley's are stock but
I bet I just didn't line things up right.

iiad,

Actually I have some really nice recording gear
(http://www.pollyputthekettleon.com). I might take you up on the offer
and go sample some sounds. The best way I can describe it would be a
"buzz". Sort of low to mid-range. Around maybe 150-500hz. I'll go
see about the pulley lining up and if it doesn't work I'll sample the
sound.

Thanks!

Chronologic

Chronologic wrote:
> Jan,
>
> That sounds very likely and is a good thought. Since I have been
> screwing around with the alternator maybe I just bolted it down a
> little too far forward or aft. I think all the pulley's are stock but
> I bet I just didn't line things up right.
>
> iiad,
>
> Actually I have some really nice recording gear
> (http://www.pollyputthekettleon.com). I might take you up on the
> offer and go sample some sounds. The best way I can describe it
> would be a "buzz". Sort of low to mid-range. Around maybe
> 150-500hz. I'll go see about the pulley lining up and if it doesn't
> work I'll sample the sound.
>
> Thanks!
>
> Chronologic

maybe you could find the noise here.
http://home.arcor.de/silke.fokken/sounds/
David

Well, I don't think I'll be posting those sound bytes aiiad.

I went back out to check the position of the alt as per Jan. Sure
enough based on the wear marks from prev. install I had it pitched a
bit back (fif). So I moved it forward and retightened. The buzz has
become more and more elusive. But the belt seemed to get worse and
worse. It now flips almost on demand if I give it a good accel/decel.
I tried the belt anywhere from what seemed like too tight to too loose
and no matter what it would ride off the track. Once it even flipped
totally off and went heading over toward the fence.

So I was about to give up and get a new belt thinking this one may have
gotten warped from being installed wrong to begin with. I had my wife
come out and rev it a few times while I watched. The buzz sound had
changed character but it still seemed that it coincided with the belt
flapping. So on what was to be the last rev of the night just to make
me feel secure about that decision something happened.

Now the car won't really rev up at all. It seems like it's on 3
cylinders or something. Give it gas and it doesn't care. It is
putting out a bit of black smoke. Once it blew fire out the pipe when
my wife was turning it over trying to start it.

I am afraid that I am jinxed or otherwise doomed to not have success
with this engine. If any of you recall any of my previous posts over
the past few weeks you'll know I have had some odd things happen.
Probably mostly because I'm clueless but then that is why I'm tackling
this. The engine sat for about 10 years and I have only twice in my
life tried to fire up an engine that has sat for that long. Both times
it seemed to fire up ok but after a while something really bad went
wrong. Other time it was on a 1971 Toyota Corona that I thought might
be fun to restore. It restored pretty well actually and drove around
for a week or so before the crank busted and somehow flipped and it
started BLOWING out the carburator. I was pretty shocked when I put my
hand over it to choke it and my had got a puff instead of a suck. I
have never been an engine guy (yet) so I was like "I'm done. Something
is wrong. Don't know what but it's definitely wrong."

Back to the VW -- my new failure.

So the next thing I was going to do after figuring out this belt thing
was the valves. I have never adjusted them before and I wanted to make
sure the previous owner had done it. I didn't ever drive it enough
miles to warrant it. At this point I figure my next step is to go
ahead and remove the valve covers and perhaps the lifters and see what
things look/feel like. What with the sudden change in temperement, the
black smoke and the fire -- with my very limited knowledge and a fairly
good head I'm guessing a valve or a pushrod problem. I'm not exactly
riding high right now.

I guess on the bright side I wanted to learn and I'm definitely getting
my chance. Thing is I was hoping to actually DRIVE my bug as well.

If I can't figure anything else out at this point my engine is probably
toast. So I will have the choice of buying a repacement, doing a
rebuild, or both. I'm leaning toward both so I can put in an engine
that someone with a clue built while I muck around and make my mistakes
on the other.

Later RAMVA.

Chronologic

Chronologic wrote:
> Well, I don't think I'll be posting those sound bytes aiiad.
>
> I went back out to check the position of the alt as per Jan. Sure
> enough based on the wear marks from prev. install I had it pitched a
> bit back (fif). So I moved it forward and retightened. The buzz has
> become more and more elusive. But the belt seemed to get worse and
> worse. It now flips almost on demand if I give it a good accel/decel.
> I tried the belt anywhere from what seemed like too tight to too loose
> and no matter what it would ride off the track. Once it even flipped
> totally off and went heading over toward the fence.

Classic symptoms of misaligned pulleys.


> So I was about to give up and get a new belt thinking this one may have
> gotten warped from being installed wrong to begin with.

Each time a belt flips and runs "sideways", it's a goner. Replace with
new. But not until you have aligned those pulleys. Also get the correct
belt.. the parts store clerk will most likely try to sell you one that
is too wide.


> Now the car won't really rev up at all. It seems like it's on 3
> cylinders or something. Give it gas and it doesn't care. It is
> putting out a bit of black smoke. Once it blew fire out the pipe when
> my wife was turning it over trying to start it.

See that your ignition timing is still correct. If the distributor
hold-down clamp is loose, the distributor will try to turn on it's own
and mess up the timing. A worn /mangled clamp might appear tight, but
won't really clamp on the distributor at all, just the clamp bottoming
out. I've seen all kinds of weird **** happen with these


> I guess on the bright side I wanted to learn and I'm definitely getting
> my chance.




> If I can't figure anything else out at this point my engine is probably
> toast. So I will have the choice of buying a repacement, doing a
> rebuild, or both. I'm leaning toward both so I can put in an engine
> that someone with a clue built while I muck around and make my mistakes
> on the other.

If you have the money, go for it. You could spend lots of time on the
other engine while still being able to drive the car. That's how one
should build high performance engines too btw.. keep one in stock shape
as your basic means of transportation, and do teh other engine right,
without having to resort to shortcuts because of tight schedule.
If only I had understood that when I started....

Jan

You might also look to see if the alternator pully has clearance against the
alternator. Mine had a groove worn in the center around the hub and was thus
real close to the alternator... and started grinding down the webbing on the
face of the alternator. I could have sworn that I was hearing the alt
bearings going.... but they are fine... course if I had not figured out the
grinding noice, I would have lost the alternator in a few more weeks in a
spectacular lockup when the front webbing got ground all the way through and
there was no longer anything supporting the one side of the shaft..... but
that didn't happen! Whew!

--
KWW
'65 Beetle (Jenny the IOC)
'64 Beetle (TBD the Blue Wave)
> wrote in message
oups.com...
> belt flipped:
>
> too tight probably.
>
> sound could be coming from alternator.
>
> remove the belt, and fire up your vehicle.
> run it through your tests.
>
> noise still there?
>
> what kind of noise? can you record it and
> put it on the internet?
>
> is it high frequency or low frequency?
> if it is low frequency, can you tell us the frequency?
> IE, 10 times a second.
>
> is it high pitch? low pitch? a bang? a knock?
> a tap?
>
> Do you have your exhaust mounted nice and
> tight?
>
> with engine running, use a long screwdriver and
> press the driver end to the engine. Press
> the handle to your ear. It works good for trying
> to find the source of strange sounds.
>
>
> PS careful with hex bolts holding tin. Use a
> torque wrench, or you will start stripping out
> your case.
>

Here's something that might help... it will take you to John Muirs
"engine sounds"
http://home.arcor.de/silke.fokken/sounds/