The Cal-look Lounge

I have a slight whistle coming from my Scat doghouse fan shroud that just bugs me.  I know many of the aftermarket shrouds have this issue, but was told that wasn't the case with the Scat version.  I've checked fan clearance.  No issues there.  I've replaced the fan with a Berg version.  No change.  I'm kinda stumped where else to look and hope that maybe someone else has found the source and the cure.  My next option will be to go back the a OE Doghouse.  (probably a new mexican version), but I really prefer the look of the Scat version if I can sort out the whistle issue.  Any suggestions?  Thanks!

...Ed.

are you sure its the shroud,new brushes in a gen. tend to do the same thing.

The Generator in OE new Bosch.  It's still possible, and worth checking.  Thanks!

...Ed.

Ed, the way to check if it's the gen. is take the belt off and start it for a min. and listen, if it stops, there ya go, if not, it's in the shroud. Never had that problem with my Scat shroud before.

Ted

If you take the belt off, the fan doesn't turn. I bet if the shroud whistles, it's because of air going through it or something rubbing the fan.  ;)

Somewhere I read the internal vanes are only tack welded to one side of the shroud...front/back.. I don't recall. It was recommended that the non welded side be siliconed to stop them moving around.

Yes, in the past when I used a Scat type shroud, I siliconed all the gaps in the vanes ala Mark Herbert recommendation.  Gap = potential annoying whistle spot.

Also, grab the top of the shroud and push and pull it lightly frontwards and back, maybe something is rubbing and that will fix it. 

Hahaha! Yup! Your right, had a long day Sat., brain was qt. low.

Ted

I had the same condition on a past car.  It had a brand x shroud so I switched back to OE German and the whistle went away.  I know many other guys who use the Scat shroud with no whistle so I was hoping to have the same.  The whistle is really faint compared to some I've heard, but its there.  Just hoping someone else had the same and found the cure.  I'll check the generator if at all possible to pin the sound there, but I'm guessing its the shroud.  The silicone idea is good.  I might try that too, or just give up and go to a OE Shroud.

Thanks!  ...Ed.

A "Thing" shroud is cool!

Ted

I think we've all been there, Ted!

Ed, could it have something to do with the shroud having the heater outlets? The 36 shroud wasn't really designed for them, so maybe it's just a weird by-product of the adaptation. Maybe temporarily plug them, and see if it changes.

Reach back there and see if there is something stuck in the fan. I sucked a receipt up once that made a noise like that.

Yeah...I was thinking the heater ducts too.  The other cars I've heard using scat shrouds did not whistle, but there were all non heater duct.  I did some adjusting to the generator today but no better results.  I don't think there is a fix other than to replace the shroud with a OE version, so that's my plan.

Thanks again for the input.

....Ed.

For what it is worth I have used Scat 36 style shrouds for years and never had the whistle until I went to a welded/balanced fan. Since that change I have not been able to escape the whistle.

Jeremy

I would tend to think the heater ducts would too big to cause a whistling sound...?.. I mean a larger opening would cause a "lower tone" in my opinion more like a "Hmmmm" ever try "whistling" with your more mouth open..?...LOL...would look funny..!...I think it would have to be a "Smaller" hole or opening...Have ya messed with "Belt tension"

It's for sure the shroud and not the belt or generator.  The Heater ducts have like a ice cream scooper inside eah opening so I'm guessing that could be it.  Either way I give up and will use a factory shroud.  I'm sure it's probably better cooling anyway.

Ed, You may try running a smaller bottom pulley and that should eliminate your whistle...

It whistles at every rpm so pulley size won't help.

Thanks again for all the suggestions.  Its just the nature of the beast, (aftermarket shrouds), I think.

...Ed.

No whistles here.  although my heap is so loud I couldn't hear it anyway

Ed, It whistles at every rpm?  Do you mean in the upper rpm region?  A smaller pulley will decrease the pressure zone within the shroud as it will slow the fan speed somewhat thereby lowering the pressure anomaly. Unless of course if this is happening at various rpms in the lower range then you have the dreaded P.O.S. syndrome....    Good Luck.

P.O.S. syndrome.....that's funny, but so true with many aftermarket parts.

Yeah...that pretty much says it.
Its going to be too dificult to pinpoint the source.  Heater Ducts...loose vane...non welded vane...gap in vane...silicone required in vanes.  Non of this should be happening.  Plus what I've read about cooling just confirmed that I need to use a OE Shroud.  I know many guys use the aftermarket versions with good sucess, but for me, I've had a couple now and they've all been stinkers.

Ed
...Ed.

Ed...both of my cars have the aftermarket shrouds....both whistle. One has a stock size pulley and one has a power pulley. One has a welded fan and the other does not. Niether have heater ducts. I found that if you turn up the radio...it goes away!

Yeah...I've been using the noise canceling knob, (radio volume), for the past couple of years.  It actually works pretty well!  :-)  Honestly, I really like the exhaust sound of a vw, and even more so the sound of 42 webers.  Hate to have it interrupted with some goofy whistle sound.  Its gotta go!

...Ed

Well the new shroud did the trick.  No more annoying whistle.  I wasn't sure if I'd like the look of the OE shroud, but now that it's in, I really do.  Really just glad that it sounds right to me now.

...Ed.

  Ed.. Congrats on your "New" stunning look.... now THATS what a nice engine bay should like and ...now quiet and OEM old school. If you miss the whistle just be secure in your manhood /LOL...    Engine bay looks 'Sweet".......

Ed, looking real good, I like it!

Ted

Thanks guys.  I sure like the way it sounds now.  100% improvement.  Here's a little better picture.

...Ed.

It looks 1000% better than a shitty Chinese shroud.

857% better. LOL

Looks great.  Heat is nice to have, too.  Getting rid of those small annoyances makes driving the car much more enjoyable, doesn't it? 

Yep Mike...you are so right.  I've been pretty happy with the end result of my Ghia, but I had a few things that were still bugging me.  The 145's on the front road like crap so I switched to a 165-60 conti.  Much much better ride, braking, and turning.  The shorud whistle was another issue that I was not happy with.  Enjoy driving the car even more now that its gone.   Having better working heaters is a nice benifit too.

...Ed.