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Discussion Starter · #1 ·
Just passed 200k miles. The coupling for the water pump (a sleeve bushing) "wore down" inside at the cam spline end, which is also a bit worn. So next time you change the pump, check the coupling for wear.

Got it fixed at a good shop in Port Aransas. Coupling was a bit hard to find and also pricey.

But now I have a mystery for the experts. Start engine, use climate control trick to track coolant temp, it gets to about 110 and starts to oscillate between 108 maybe and 120, back and forth thru the numbers for about a minute, locks on 135 and SES lite comes on. Now figure that one out. No fair scanning.

Cheers, Roger

95 RM Wagon
San Antonio
 

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thermostat is stuck open?
 

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Coupling could be signs of worse trouble

I was replacing the water pump a couple of years ago on my RMW (about 120K miles), and also noticed that the coupling sleeve was badly worn. Mine had not quite gone entirely, but the internal teeth were just barely there. I realized that the drive stub shaft, that was also worn, had a lot of runout. I suspect that the wobble had contributed to or caused the coupling wear. I ended up replacing the stub shaft, with its gear and bearing, that operates off the camshaft. This necessitated pulling the timing chain cover. So while I was at it, I also replaced the timing chain, and then all the seals when I put everything back together.

What a design! I wonder what was wrong with driving the water pump from a pulley?
 

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Yes. The coupler gets crusty from age.. When its off, I always give it a hit of grease to help slow down corrosion and wear.
 

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"What a design! I wonder what was wrong with driving the water pump from a pulley?"

With this design when the serpentine belt breaks, you can still drive to a place to get it fixed without the engine overheating. This is a major issue if you are driving on a highway in the middle of nowhere. That's what is wrong with driving it from a pulley.

There is no need to replace timing chains on these cars in normal use.
 

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Discussion Starter · #6 ·
Thanks for input

thermostat is stuck open?
No actually more complicated. Getting trouble code 15. Will try to clear the code. If that works, great. If code reappears, will to replace the water pump temp sensor as the "new" one may be defective.
 

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But now I have a mystery for the experts. Start engine, use climate control trick to track coolant temp, it gets to about 110 and starts to oscillate between 108 maybe and 120, back and forth thru the numbers for about a minute, locks on 135 and SES lite comes on. Now figure that one out. No fair scanning.
Either bad ECT sensor or bad connection/wiring for ECT sensor.
 

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water pump sleeve

Yes. The coupler gets crusty from age.. When its off, I always give it a hit of grease to help slow down corrosion and wear.
Is there a tool to remove the sleeve from the cam and timing cover, it is stuck on and very rusty? Vise grips? It looks like it is on backwards with the line facing forwards
 

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Just passed 200k miles. The coupling for the water pump (a sleeve bushing) "wore down" inside at the cam spline end, which is also a bit worn. So next time you change the pump, check the coupling for wear.

Got it fixed at a good shop in Port Aransas. Coupling was a bit hard to find and also pricey.

But now I have a mystery for the experts. Start engine, use climate control trick to track coolant temp, it gets to about 110 and starts to oscillate between 108 maybe and 120, back and forth thru the numbers for about a minute, locks on 135 and SES lite comes on. Now figure that one out. No fair scanning.

Cheers, Roger

95 RM Wagon
San Antonio
Any way to remove the coupling, mine is stuck on and looks backwards?
 
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