Radiator fan hitting AC/PS pulley

E3AV

E3AV

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Anyone experiencing the radiator fan hitting the AC/power steering pulley occasionally? I got the black 9 blade fan. The car had a red 8 blade earlier which was damaged due to a missing radiator clamp I believe. This I have thrown away so I can’t compare them with each other.
Water pump bearing seems fine.
 
boonies said:
That is not normal. I am not familiar with the 9 blade fan and fan clutch layout. On my 5 blade fan the clutch was inside the fan and I suspect yours was as well. Assume you have a fan clutch, perhaps it is the position or spacing of the two in combination that is putting the fan too close to the other pulleys.
Click to expand...
 
I don’t believe the fan and clutch are put together the wrong way.
I think there’s only one way to do this. But I have noticed that the water pump pulley is sitting wery close to the water hose coming from the thermostat. Is this normal?
 
And there’s no more than 7-8mm clearance between the fan blade and the AC/PS pulley.
The blades on my fan feels a little flimsy and looks more flimsy than on the 8 blade fan.
I was thinking either to go back to a 8 blade fan or if I can find one, or I could remove the pulley and run the PS pump from the water pump pulley. I do have a double groove pulley available.
 
Here is a before and after picture.
Looks like the red 8 blade maybe have a smaller diameter and the blades are angled slightly outwards towards the radiator.
To bad I throwed the old one away.
IMG_5505.png

IMG_2447.jpeg
 
Those fans are clearly different Thickness of the hub ? And position of blade.
 
Last edited:
deQuincey said:
Meant a pic that shows the actual interference
Click to expand...
I’ll try taking a picture, but it’s a little bit difficult down there. There’s no interference with the engine not running. But there is tight clearance as I mentioned earlier.
Engine at idle there also no problem.

My car is currently on jack stands.

This is what I have tried and when the problem occurs:
I start the car an hit the throttle running through the gears. All fine until 4th gear and reaching 3000rpm. Suddenly a constant loud plinging noise appears from the engine compartment.
This puzzled me the first time.
Did a second "run" now with the hood open to be able to hear the sound better. No noise this time.

My conclusion this far is that the tips of the blades are hitting the pulley when the air flow pushes the fan towards the engine. The air flow is altered when the hood is open and the problem is not present.
But why only when I first go to 4th gear?
There is not much load on the engine other than the drivetrain itself as the car sitting on jack stands. (No wheels on either)
 
3,000 crank rpm should result in the same fan rpm and airflow regardless of gear if car is on jackstands (unless you have electric fan coming on)
7 to 8 mm clearance should be enough. Are you sure not hitting hood or torsion spring tube?
Maybe put some whiteout on the pulley edge you suspect and see if there is transfer to fan blade.

Nice job on the header wrap by the way
 
2000CS said:
3,000 crank rpm should result in the same fan rpm and airflow regardless of gear if car is on jackstands (unless you have electric fan coming on)
7 to 8 mm clearance should be enough. Are you sure not hitting hood or torsion spring tube?
Maybe put some whiteout on the pulley edge you suspect and see if there is transfer to fan blade.

Nice job on the header wrap by the way
Click to expand...
I don’t think the torsion spring tube sits directly above the fan. It’s more right in front of the air cleaner.
And there’s no marks on the hood and the foam padding.
Good idea regarding the whiteout though.
As you can see from the pictures there are missing some small pieces of some of the blades.
There are also some "burrs" in the dirt/rust on the pulley edge.
 
What is clearance to distributor shield?
Do you have the little metal strap that keeps the hose against the front cover?
Neither would explain why noise only with hood closed in 4th gear

If the pulley is the problem and you are not running a belt on the empty v-groove why not use a single pulley instead of the double or cut off extra?
 
Clearance to the distributor shield is 6-7cm I think, so no problem there.
Does a single groove pulley exist?
 
Your setup is the "old" version.
Later setup from 73 i think like the one I got runs the ps pump from the pulley mounted on the vibration damper and not the water pump.
One of my alternatives as I was mentioning earlier was to go back to that setup and remove the pulley on the vibration damper.
But if there’s a single groove pulley that is also an option.
 
Believe my 2500 had just the damper v-groove (no power steering), then later 2800 an add-on single pulley for cars with York AC, then the stamped steel double groove variety with alternate power steering drive from either crank (with Bosch compressor) or water pump double groove (which I hated replacing or adjusting belts on due to alternator pulley/nut rub).
The expedient solution would be just cutting off either the offending lip or the entire section for a cleaner look. Lathe work recommended, but nightmare visions of u-tube video showing protective gear and hand disc grinder on idling engine :rolleyes:
 
E3AV said:
Your setup is the "old" version.
Later setup from 73 i think like the one I got runs the ps pump from the pulley mounted on the vibration damper and not the water pump.
One of my alternatives as I was mentioning earlier was to go back to that setup and remove the pulley on the vibration damper.
But if there’s a single groove pulley that is also an option.
Click to expand...
yes 1971
 
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