Nasty sound from fan / water pump

[tdgray]

So I’ve been try to isolate this annoying thunking sound from the engine bay. I swear I thought I spun a main bearing but it didn’t act like it.

I suspected maybe a water pump. Even though I wiggled the fan a dozen times I finally got it in the right spot…. Yep that’s the noise.

The question is before I rip this apart. Is this most likely the water pump or the fan and clutch? I thought I read somewhere here that if it’s the fan assembly I’m kinda screwed.

Any thoughts?

 

[Thomas76]

Is there evidence of fan blades hitting something? The plastic is notorious for cracking.

 

[bluecoupe30!]

How long have you owned this car? Do you know its repair history? Age of water pump? If this car is new to you, it is an excellent time for you to refresh the entire cooling system, flush radiator or rebuild it to 3 core status, and so on. Not that difficult, but very rewarding. As above, those fan blades are old. Good luck and keep us posted.

 

[eriknetherlands]

I'd suspect your waterpump firstly, as it has internal bearings and seals to keep the fluid on one side - a notorious combination.

 

[tdgray]

This is the new to me 2800CS that I’ve been poking at before it undergoes a restoration this coming winter. So I know nothing of its history.

Yes, to me it sounds like a bearing. There is one blade of the fan that has a chunk of the blade missing. i assume that these fans are NLA. Have not looked.

 

[Stevehose]

5 blade fans are still available but not their clutch, you’re better off getting the newer 9 blade fan and screw-on water pump/clutch combo, not expensive and better performing.

 

[tdgray]

Thanks Steve… that does sound like a better way to go. I’ll check and see who sells these.

 

[Ohmess]

In Rob Seigel's Hack Mechanic book, he has a chapter on making an old car reliable. It is he recommends reworking the entire cooling system. In addition to the recommendations made by bluecoupe30! and Stevehose, replace the belts and hoses.

 

[Arde]

This is the new to me 2800CS that I’ve been poking at before it undergoes a restoration this coming winter. So I know nothing of its history.

Yes, to me it sounds like a bearing. There is one blade of the fan that has a chunk of the blade missing. i assume that these fans are NLA. Have not looked.

Oh, the imbalanced broken blade wore down the bearing. Classic, if the clutch was stuck attached even worse...

 

[tdgray]

That's a big question... is the clutch toast. Well I guess we will find out when I pull it.