C4 Water Pump
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Intermediate
Joined: Nov 2006
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C4 Water Pump
Hello, I have a 95 C4 with only 70K miles. It's on it's 4th water pump. I only use Delco pumps. Any thoughts as what is happening? Can the spline connector tube be too long and is placing a load on the pump bearing?
Thanks, Ken
Thanks, Ken
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
that's an average of 17.5K miles per WP. Either you have had extremely bad luck from your source of the OEM WP(which I doubt) or you definately have another issue. When they fail, is the WP leaking from the weep hole, or is there another failure mechanism involved like loud "scratching" bearing noise? When you install a new WP, there should be not resistance during mounting procedure. If you have to add any additional force when fitting the new WP to the front to the engine, then yes, your connector spline may be to long causing premature bearing wear due to forward/uneven pressure on the bearings.....
Last edited by MikeC4; Jul 19, 2007 at 08:07 PM.
Burning Brakes
Joined: Aug 2006
Posts: 1,189
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From: Houston PA
My Delco lasted 40K, thats the total miles on the car. I was not about to put that same brand on it again, a pump should last a lot longer than that. I got a lifetime warranty pump at Auto Zone, about $100, and Ill never buy another one again.
Burning Brakes
Joined: Dec 2000
Posts: 1,161
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From: Orangeburg, NY
MikeC4 has made some good points. Several things may be happening. Check the water pump pulley to make sure it is not bent and it is properly lilned up. If it is bent or misaligned it will cause undue stress on the water pump bearings. Check the tensioner to ensure it is not putting too much pressure. check the belt to make sure it is the correct size.
Race Director
Joined: Dec 2006
Posts: 10,383
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MikeC4 has made some good points. Several things may be happening. Check the water pump pulley to make sure it is not bent and it is properly lilned up. If it is bent or misaligned it will cause undue stress on the water pump bearings. Check the tensioner to ensure it is not putting too much pressure. check the belt to make sure it is the correct size.
If one were to take the kernel of wisdom from Bob and apply it to the LTx he would look to the timing set's output shaft and make sure it wasn't tight agianst both the pump and the timing cover at the same time.
There was a great write up on converting the LTx pump to electric and I've thought about it for the oh ah factor but if I had gone through four gear driven pumps I would certainly be looking at it just to keep her on the road.
<edit> Oh I just had an idea. (rare that!) What do you guys think about him installing two gaskets instead of one? It would make the distance from the timing cover to the back of the pump just a bit longer. Would that hurt anything if clearance wasn't the problem? Would it help if clearance was the problem?</edit>
Last edited by 94z07fx3; Jul 20, 2007 at 12:01 PM.
Melting Slicks
Joined: Feb 2005
Posts: 3,204
Likes: 4
From: Midland Georgia
St. Jude Donor '06
That's perfectly sound advice for the vast majority of cars ever made. But not for the LT1 or LT4 with the gear driven pumps.
If one were to take the kernel of wisdom from Bob and apply it to the LTx he would look to the timing set's output shaft and make sure it wasn't tight agianst both the pump and the timing cover at the same time.
There was a great write up on converting the LTx pump to electric and I've thought about it for the oh ah factor but if I had gone through four gear driven pumps I would certainly be looking at it just to keep her on the road.
If one were to take the kernel of wisdom from Bob and apply it to the LTx he would look to the timing set's output shaft and make sure it wasn't tight agianst both the pump and the timing cover at the same time.
There was a great write up on converting the LTx pump to electric and I've thought about it for the oh ah factor but if I had gone through four gear driven pumps I would certainly be looking at it just to keep her on the road.
Sounds like it is time to consider the electric pump~!
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
Here's a thought:
The sleeve that connects the water pump driven gear to the water pump has a groove around one end....even though you can make it work either way, it is supposed to go on one way.
That groove goes toward the timing cover -- not the water pump.
Tom Piper
The sleeve that connects the water pump driven gear to the water pump has a groove around one end....even though you can make it work either way, it is supposed to go on one way.
That groove goes toward the timing cover -- not the water pump.
Tom Piper
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Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Here's a thought:
The sleeve that connects the water pump driven gear to the water pump has a groove around one end....even though you can make it work either way, it is supposed to go on one way.
That groove goes toward the timing cover -- not the water pump.Tom Piper
The sleeve that connects the water pump driven gear to the water pump has a groove around one end....even though you can make it work either way, it is supposed to go on one way.
That groove goes toward the timing cover -- not the water pump.Tom Piper
I didn't, and still don't, know what difference it makes but "why take a chance" was my thinking.
Jake
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Intermediate
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that's an average of 17.5K miles per WP. Either you have had extremely bad luck from your source of the OEM WP(which I doubt) or you definately have another issue. When they fail, is the WP leaking from the weep hole, or is there another failure mechanism involved like loud "scratching" bearing noise? When you install a new WP, there should be not resistance during mounting procedure. If you have to add any additional force when fitting the new WP to the front to the engine, then yes, your connector spline may be to long causing premature bearing wear due to forward/uneven pressure on the bearings.....
Thx, Ken
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Interesting. Also, did you make sure that the spline connector is oriented correctly as JAKE pointed out? The groove goes towards the engine:
#37=WP , #39=spline connector, #83=engine drive shaft
Shaving off a couple of hundreths might not be a bad idea if you noticed crushing of bearing seal.
Good luck....
#37=WP , #39=spline connector, #83=engine drive shaft
Shaving off a couple of hundreths might not be a bad idea if you noticed crushing of bearing seal.
Good luck....
Thread Starter
Intermediate
Joined: Nov 2006
Posts: 29
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Interesting. Also, did you make sure that the spline connector is oriented correctly as JAKE pointed out? The groove goes towards the engine:
#37=WP , #39=spline connector, #83=engine drive shaft
Shaving off a couple of hundreths might not be a bad idea if you noticed crushing of bearing seal.
Good luck....
#37=WP , #39=spline connector, #83=engine drive shaft
Shaving off a couple of hundreths might not be a bad idea if you noticed crushing of bearing seal.
Good luck....
Hi Mike, the spline connector was improperly installed last time. I'll make sure it correct this time. Thx, Ken
