Cooling system weirdness -- solved!

[treynor]

Some of you may recall my frantic note of last Friday night. My Viper's temp gauge had been acting weirder and weirder over the past few months, and swapping the radiatior (for a fluidyne) and the thermostat (for a 180-degree unit) had not helped. I'm thrilled to report that Ted May, our local Viper Tech, diagnosed and fixed the problem in one afternoon: faulty water pump! I'll let Ted chime in on the details, but my neophyte impression was that the impeller had cracked along the main shaft it rides on, and was able to spin independently of the shaft -- thus it probably was spinning at only a fraction of the speed it needed to, if at all.

Ted replaced the water pump, refilled the cooling system, and voila! it runs perfectly again. I can't make the temp needle budge from 175 as long as I'm moving -- full throttle 30-80 mph bursts which used to bring the temps up to 225 now have literally no visible effect. I now can go to the Monterey meet tomorrow in my Viper, instead of slumming in some other vehicle.

Ted, many thanks!

 

[phiebert]

I'd love to know if there are any certain symptoms of a water pump problem because mine has been a little strange lately too. I've done a number of mods (exhaust, plugs, smooth tubes, etc.) but wondering if there is a problem or if it is normal. It seems somewhat unpredictable as to when the gauge will go up. It pretty much stays at normal when moving but sometimes when moving slowly it really climbs fast. Then the fan kicks in and it drops quickly again. Thoughts?

 

[treynor]

The Fluidyne works beautifully now that I have a functional water pump. I unfortunately can't compare it directly with the stocker, as my water pump was already going bad when I swapped it in, and I've changed too many other things since (thermostat, heads, etc.). However, I'll say that I tried a bunch of short (2-5 sec) acceleration runs last night, and nothing made the temps go above 180 deg. The car's clearly got cooling capacity to spare. We'll see how it does at the 'strip, and later perhaps on the roadcourse...

FWIW, I got my Fluidyne & thermostat through Parts Rack.