Screeching from LA Engine, Water Pump

[1970FuryConv]

For all the small block V8 guys 1970 and later, this happened on my 1990 360V8 truck, but it could just as easily happen in one of our cars (same water pump). I was driving home from work and suddenly heard a loud screeching noise that varied with engine speed. I stopped at a gas station, looked under the hood, and oil and gunk was spraying from the front of my water pump. I shut the car down. I grabbed the fan and was able to move it forward and backward by hand, but it wasn't hitting anything. I thought: bad bearing couldn't possibly make that much noise.
But a propeller hitting the timing chain cover/wp housing and water pump can

From the pics above and below, you can see the exposed spring end

My question is: What normally keeps this spring compressed? Is there something like a valve spring retainer and keeper? I found no loose metal parts or pieces when I removed the pump. Thanks, Ben

 

[65sporty]

I thought everything was a press fit, bearings pressed on, impeller presses on, etc.

 

[MrMoparCHP]

Just be lucky it didn't take out your radiator, that happened to me.

This failure isn't that uncommon.


Alan

 

[Davea Lux]

Just be lucky it didn't take out your radiator, that happened to me.

This failure isn't that uncommon.


Alan

The real fun comes when it fails the other way and the impeller eats the timing cover. One of the reasons I no longer use rebuilt water pumps, but one has to be careful as many of the new aftermarket pumps are now made in China. I have had really poor luck with just about all parts being made there.

Dave

 

[Davea Lux]

For all the small block V8 guys 1970 and later, this happened on my 1990 360V8 truck, but it could just as easily happen in one of our cars (same water pump). I was driving home from work and suddenly heard a loud screeching noise that varied with engine speed. I stopped at a gas station, looked under the hood, and oil and gunk was spraying from the front of my water pump. I shut the car down. I grabbed the fan and was able to move it forward and backward by hand, but it wasn't hitting anything. I thought: bad bearing couldn't possibly make that much noise.
But a propeller hitting the timing chain cover/wp housing and water pump can
View attachment 169109
View attachment 169110
From the pics above and below, you can see the exposed spring end
View attachment 169111
My question is: What normally keeps this spring compressed? Is there something like a valve spring retainer and keeper? I found no loose metal parts or pieces when I removed the pump. Thanks, Ben

Pretty sure these were an all pressed fit, I think from what I can see in the photo that the inner bearing disintegrated and left the seal compression spring exposed. You might check the FSM to see if there is an exploded view of the water pump to see if there was a snap ring or other retainer, I do not think that there was. Probably would be a good idea to run a magnet inside the timing cover ports to see if there are any loose parts in there.

Dave

 

[cantflip]

The magnet idea isn't a bad one, but the good news is wherever the aluminum shavings settled, they are unlikely to circulate and get back into the new pump... your replacement should be safe.

FWIW, many pumps are designed with the impeller blades toward the housing. This RB pump would eat the housing with a similar bearing failure. When the pump is replaced without a new housing, the coolant flows... but not as well as it should. This is one way many mystery cooling system problems are created. Pumps are cheap, housings are more expensive... and as Davea Lux said... quality is lacking in many replacement parts.

 

[traintech55]

As stated earlier this was a common problem on the early new style water pumps. In the middle 70's Chrysler phased in a stronger water pump identified by small holes cast into the housing , (these are refereed to as the Police water pumps). All the new ones use this design thru the late 80's and they totally interchange.

 

[1970FuryConv]

The real fun comes when it fails the other way and the impeller eats the timing cover. One of the reasons I no longer use rebuilt water pumps, but one has to be careful as many of the new aftermarket pumps are now made in China. I have had really poor luck with just about all parts being made there.Dave

I never use rebuilt water pumps or distributors or master cylinders. They don't sleeve the shaft housing, so there's too much play, reduced life, and increased leakage

 

[1970FuryConv]

I tried the magnet:got nothing
Here is the HD NAPA water pump I used, $106.99 but I got 15% off. Really smooth and tight when turn impeller.

Seems you can see spring end exposed so that must not mean anything. It must be that the press fit wore out and the components became loose.

Installed

Doesn't leak a drop. Gasket comes with. Looks like Felpro 6584. Permatex #2 on threads of lower 4 bolts. Install all 7 bolts at 30'lbs per FSM.

 

[Davea Lux]

Most of the time, you will not find debris from a pump bearing failure in the block, the pump is designed not to do that. It is always a good idea to check, if for no other reason than your own piece of mind.

Dave

 

[1970FuryConv]

Most of the time, you will not find debris from a pump bearing failure in the block, the pump is designed not to do that. It is always a good idea to check, if for no other reason than your own piece of mind.

Dave

I drove the truck 68 miles on Friday with no leaks and no screeching noises. I'm happy. Thanks for the guidance. Ben