TheSamba.com :: View topic - Fan noise sounds like hitting the fan casing

Fri Jan 14, 2011 11:55 am

I just imported (to France) a completely rebuilt 1971 T2 from California.

After resolving what appeared to be a couple of teething problems with getting the motor tuned up, I thought I was ready for some enjoyment with my bus. However, just after getting the family packed up for the first outing, I noticed an increasingly loud scraping sound. When the motor was running.

It appeared to be coming from the fan casing and judging from the increased intensity of the clacking with increased acceleration, I assumed it was the fan.

I brought it to the shop directly.

A mechanic took a look at it while he was installing a new starter (went in the first week of arrival....).

He thought he fixed it. After driving another 2 miles, sound started again...

Brought it back and he now feels that he may have to take the engine out to see what the problem could be. This will surely be very expensive, but I don't see any other way.

Would greatly appreciate if anyone had any insight into what the problem could be and if there is a remedy with out taking the engine out.

I am very new to the VW bus world and had hoped things would have gone better to start.

Thanks a bunch

Fri Jan 14, 2011 12:02 pm

taking the engine out of a T1 engine bus (1971 upright engine vs later 1972 on T4 engine style) is fairly easy - maybe 1 hour work, I used to be able to do it in 15 minutes. A pair of guys probably hold the record in under 2 minutes. It could be anything from a loose nut to a bad bearing to something that fell into the openings when it was being transported.

Fri Jan 14, 2011 12:15 pm

Great news. I will have to bring a stopwatch when I mention this to my mechanic.... lol.

Although he is specialized in German vehicles, I think it is probably the first time he has worked on one of these vans. There are just not many of them in this neck of the woods. Perhaps I will have to look for a new mechanic.

Thanks again for your quick response and insight.

Regards,

Scott

Fri Jan 14, 2011 12:16 pm

I agree pictures would help here, it could be a 71 with an upright type 1 engine or a 72 model built in late 71 with a flat type 4 engine, completely different systems.

If it is a type 1 remove the fan belt and see if the noise stops, don't run it more than a minute or two like that though, no cooling.

I assume your oil pressure and charge lights work?

Fri Jan 14, 2011 12:35 pm

It was originally a 1600 cc that was upgraded to a 1835 duel carb system.

Looks real nice, but I think that there person who rebuilt it did not tighten everything to spec. In the first week, the pully wheel connecting the belt to the motor already feel off....

Had to reassemble on the side of the road in the rain.

Any way, that is a good idea to run it for a minute with out the belt connected. I am sure that it will not make the noise. It seems clearly to be coming from the fan casing and at the same frequency as the motor (ie clear when one accelerates the motor). So I believe some how the fan is touching the inside of the casing.

Thanks again for the feedback.

Fri Jan 14, 2011 12:39 pm

If you have a generator, maybe you just need to shim the bottom of the generator and the top of the stand? I've used an aluminum soda can and flattened it for my bug. It fixed it really good and is unnoticeable. Good luck!

Fri Jan 14, 2011 12:50 pm

Thanks, Not really sure what that means, but will mention it to the Mechanic. There used to be an alternator but with the engine upgrade, they put in a generator. perhaps this has something to do with it??

thanks for the input

Fri Jan 14, 2011 2:05 pm

Remove the belt like Bus Daddy says to confirm it is the fan.
With dual carbs there is no need to remove the engine. Only remove it with the original stock carb and manifold that are in the way.

Reach around in front of the fan shroud and see if you can determine if the fan is loose or is rubbing on the fan shroud or if it wiggles if you push and pull hard on it.

-First thing to do is loosen the bolts holding the fan shroud and also the clamp holding the generator. Then wiggle the fan shroud to see if repositioning it stops the rubbing.
-If that doesn't solve the problen remove the generator and fan. You should be able to determine where the problem is. There are usually 2 causes of that problem.
-One is the fan is not properly installed and shimmed onto the generator. There needs to be the specified clearance between the fan and the 4 bolt large mounting plate that the generator bolts to. Check it per the specifications in your manual. You problably have the Haynes manual but the Bentley service manual is what you really need and should get.
-The other cause of the problem is a broken fan. They commonly crack in a circle right around the O.D. of the washer that holds it onto the generator. Wiggle the fan and you might see the crack. You might not be able to see the crack as it is right at the edge of the washer. Remove the nut and washer and the fan and carefully check for a hard to see crack.

BTW some people can remove and replace the engine quickly and they usually have all the wonderful jacks, lifts, tools, and prior experience. But frequently engines are put back in and bolts are loose or left out and other things are not done in quality manner. I have removed and replaced bus engines a few times and I always plan on a day job to put the engine back in while taking the time to inspect and do all the related things correctly to avoid future problems. Such as new fuel lines, clutch and throttle cables, etc. Or I could do it in an hour and possibly leave a bolt loose, pinch and damage a wire, or not clean wire connections, and all the many other details.

Fri Jan 14, 2011 2:12 pm

I recently dealt with the exact same problem. Three times in one month.

First diagnose it correctly.
1. Start the car - you should hear the fan rubbing the inside of the housing.
2. Open the engine compartment, reach back to the top of the fan housing, and push the fan housing back and/or pull it forward.
3. If the fan is rubbing, your movement of the fan housing should make it stop - one way or the other.
4. If the sound doesn't stop while you are playing with the housing, it's probably not the fan. If it does stop, it's the fan.

Second. Permanently solve the problem.
1. Shimming the generator is a temporary solution. It will keep the fan from rubbing, but the real problem is your alignment. Either the fan housing is not lined up correctly, or the fan isn't.
2. Get in the engine compartment and make sure all the engine tin is put in correctly. It is common for new mechanics to *not* get all the fan house tin tucked into the head shrouds. The back side of the fan housing tin is notorious for not being placed *inside* the tin. This would cause the fan housing tin to lean forward, and the fan to rub.
3. If the tin is not installed correctly, install it correctly. (of course)
If it is installed correctly, then it is likely that the fan needs to be shimmed for a wider distance between the generator backing plate and the fan.

Look at this picture:

You will see a compete even space between the fan and the backing plate. I had to install a shim to make this distance correct and keep the fan from rubbing.

I hope this helps. Good luck. It took me about two hours to remove, adjust, reinstall the fan.

Fri Jan 14, 2011 3:09 pm

what Desertbusman said

Fri Jan 14, 2011 5:49 pm

VWDruid wrote: what Desertbusman said

What did he say :lol: I wish i could watch the vid and see what it's all about. But my Windows Explorer 6 is no longer workable with Youtube and many web sites in the last couple months. And can't upgrade to IE 7 and 8 with my old Win 98SE or Win 2000. Bummer.
Curious as to what the OP runs into.

Sat Jan 15, 2011 10:16 am

Just wanted to thank everyone who took a few minutes and helped out a stranger in need...

I have read and printed out all the comments.

I have viewed and saved the videos and photos.

My feeling is that something (shroud, fan or generator) must have gotten slightly out of alignment somehow while getting tuned up or having the new starter installed.

Optimistic that I can get her back on the road soon.

Thanks again to all and best wishes for the new year.

Sat Jan 15, 2011 3:06 pm

The nut holding the fan onto the generator shaft may be loose. With the engine off reach around and feel inside the hole. Try to wiggle the fan.

Sat Jan 15, 2011 5:26 pm

aeromech wrote: The nut holding the fan onto the generator shaft may be loose. With the engine off reach around and feel inside the hole. Try to wiggle the fan.

this is most likely problem, you can even do it yourself. are you totally against pulling the enigne yourself and trying to fix it at home? engine drops are much easier than you think, and anyone with a jack can do it on an early bay, even if you don't have a flat driveway. just put the jack under the motor and push the car away from the motor, insteast of the other way around.

Sun Jan 16, 2011 8:40 am

I would disregard that vid. For one thing, he's working on a Beetle. And the generator wasn't oriented properly to begin with, no wonder there were problems with it, it probably overheated. Listen to what Aeromech and Desertbusman remarked.

Sun Jan 16, 2011 9:47 am

Will roll up the sleeves and get into it first thing tomorrow.

There is not much room to get in back of the shroud. Just enough to get a hand - or rather a few fingers - on it. Could not move it or at least could not detect movement with the contact that I had.

By the way, the person who rebuilt the engine, put a cosmetic red disk in front of the generator. It appears that with this there are no longer any shims in front of or between generator pulley wheel. Is this normal?

Tried to attach a photo here, but could not get it to work.

Thanks for your help

Sun Jan 16, 2011 10:28 am

Jody '71 wrote: I would disregard that vid. For one thing, he's working on a Beetle. And the generator wasn't oriented properly

Jody is right about the generator alignment, you'll have to watch part 2 to know why alignment is important.

and maybe all 4 videos before disregarding them completely.

type in Generator Replacement in the search http://www.youtube.com/user/6d4vdub#p/search

Sun Jan 16, 2011 11:51 am

OK, It MAY be that you have the incorrect generator on there if indeed you have a 38amp generator backing plate. Or, you could have the correct generator with the wrong backing plate. What does your generator say? The backing plates are dished differently for 30 and 38 amp generators. Sounds like that's what your problem is, or maybe could be. Stock for '71 Bus with all correct components is per Bentley (with a new fan belt) Chapter 9 "Lubrication and Maintenance, page 10, which shows 4 shims in between the two generator pulley wheels. Also take note as to how well the generator (with the fan belt still installed) is aligned with the rear crank pulley. Both pulleys have to be on an even plane.

Sun Jan 16, 2011 1:30 pm

Thanks for the comments.

I will check in the morning when I get the bus back.

To give a bit more information, the bus has been driven about 300 miles since the engine rebuild was finished with out any fan rubbing noise.

It has only started just recently after I got the bus back from having it tuned up and a starter installed.

Since the noise arrived, it has only been driven about 4 miles.

My question is that if the generator or plate was wrong would it not have made the noise from the very beginning?

Thanks for the help

Sun Jan 16, 2011 2:03 pm

floripa6 wrote: My question is that if the generator or plate was wrong would it not have made the noise from the very beginning?
Possibly, or something has now slipped or bent either due to poor initial assembly or the reaching around the shop did to get at the starter bolt.

Quote: By the way, the person who rebuilt the engine, put a cosmetic red disk in front of the generator.
Hmmm... if they were amused by aftermarket crap like that I wonder if they used a cheap chinese fan? It could have cracked in 400 mi..