Vandit

So I finally put my car's engine back together this weekend, including my new/used replacement fan, all prettied up w/ powdercoating and what not.

I've only run the car at idle (it's still on jack stands) and rev'd it up a bit, but that's about it. Maybe 20 mins run time, max.

So I go to inspect the housing and find this. There is no audible hitting/clanking noise at all.









The rubbing is on random spots across the circumference of the housing, not just the bottom, so I do not think it is strictly belt tension related.

You can see the fan I removed in **this post**. It was very trashed.

So i'm reusing the fan bearing, alternator, and housing from the old assembly. I only replaced the fan and I had the housing and fan powdercoated. I didn't perceive any play in the bearing or alternator shaft.

So what could be happening here? I know the powder coating appears to have gone on pretty thick on the housing and on the fan. You can see how it has built up a bit towards the edges of the fan blades. Do you think this could be causing the problem?

I know that the fan isn't perfect, either because of the fan, or because of the coating. I tested this by putting it super close to a solid object and spinning it (on the fan bearing, alt shaft stationary) and at least 2 of the blades would just barely touch while the rest did not. Very minute tho.

What should my next step be? If I get the alternator rebuilt, will they be able to tell me if the alternator shaft is not true (is this even possible?)? OEM fan bearings cost a grip!

1990-964

Looks like the beginning of fan bearing failure.

Vandit

Should I just pull the trigger on an RS hub? I can probably get the alternator rebuilt locally plus buy an RS hub for the same price as the OEM fan bearing.

Would the RS hub use the same belt size I currently have? I don't recall the size, but I know both pulleys are currently running the same size belt (just bought them brand new!).

swaini

+1 on the bearing failure.. had the same situation, but the yellow car of ur fan makes identification much easier... in my case it started with a short erratic cling like a bell..... turned out to b bearing failure.. and minor cracks in the fan... changed both. good luck.

Vandit

What's the best place to get a quality fan bearing for a good price? Pelican is north of $200.

I'm thinking RS hub, but I'm afraid of charge issues if I get caught in traffic that is typical of DFW and my commute.

PNine64

Fwiw, I remember reading that the powder coating increased the overall diameter of the fan to a point where there was a tendency to rub. Some have sanded the tips to resolve the problem. This does not mean that other issues didn't exist on those...or yours...it's just a data point.

Vandit

That's what I was thinking too, plus the coating on the housing too.

I'm also thinking my old fan was pretty trashed and likely somewhat out of balance, so it would be likely that this bearing has been beat on more than a bearing that supported a structually sound fan.

I just don't want to kill another fan. I got a good deal on this one. I likely won't be as lucky if I have to source another.

Goughary

Fwiw - i just made the change to the RS hub - and have a long commute in stopped traffic twice a week (an hour in stop and go). So far, though I am not using the AC, all is just as normal. No charge issues at all.

Vandit

I could see it being a problem during Texas summers. Sitting in traffic, oil cooler fan on high, condensor fan on high, interior A/C blower on high, rear engine blower on high. Lots of power usage right there.

New bearing in the way from Sunset Porsche! They floored Pelican's price by like $90.

Looks like I'll be tearing back into it tonight. Hopefully the fan is still okay.

CBR786

I did the same powder coated fan and housing and installed RS hub got the exact same rubbing on the shroud with me it was just excess powder on the tips of the blades scraping off.

I would just confirm by grabbing the fan and trying to see if any play ? if play present then bearing on way out.

Vandit

Hmmph. I don't preceive play in the assembly, but I can't make the determination that it occurring due to the coating thickness either.

Since I don't know the age of the alternator (might be OEM, 96k mi) and I don't know the age of the bearing (lesson = buy a car w/ service records, folks!), I'm gonna take the most conservative approach, which is what I should have done prior to reassembly.

I've got the new parts headed my way and I found a local shop that will rebuild the alternator.

AOW162435

I think the issue is a combination of tight tolerances due to the powder coating, as well as a worn fan bearing.

Not sure what you paid for the bearing, but I'm selling a brand new factory bearing on Ebay at the moment for $110.

A few other points - make sure your belts ride snug, but not tight. Overly-tight belts will wreak havoc on alternator bearings. Make sure that the fan housing strap bolt is snug. Too tight and you risk distorting the housing, which in turn tightens up the fan blade-to-housing gap.


Andreas

Vandit

Alright, just to update, I got the alternator professionally rebuilt, I replaced the fan bearing, and I added more shims to decrease the tension on the alternator and fan belts.

I took the car out tonight (first time driving it since early Jan!), ran it through its paces pretty well (read: romping on it), and the result is that the fan is still marking up the housing randomly on the circumference of the housing.

I'm just gonna live with it. If it's the powdercoating that's too thick, eventually it will wear down. If it's the fan that's messed up, oh well, that was my main focus for preservation anyway.

Marc Shaw

Did you pc the fan housing too or just the fan? Perhaps the housing is less than perfectly round after being blasted.

Marc

AOW162435

He had both powder coated.


Andreas