96 Chevy p.u.

Seems to me I've got an electrical problem. It's reading hot, but it simply isn't hot. Anybody familiar with this type of problem? It's new to me. Changed the pump two days ago, and there were/are no leaks.

After I put the new-new one on, it does the exact same thing. I guess I'll tip my hat to the "it's still got air in it" crowd. Never had this kind of trouble with the 74 Chevy or 87-90 Buicks. I leave for Ames at 0400 tomorrow morning, and it better just be air in the system, or I'll be asking if a new or salvaged engine would be best! Thanks guys.

Allan

Try changing the thermostat first. If that doesn't fix it, then it looks like you've got another water pump to install.

Just thought of one more thing. It's also possible that one of the water pump gaskets got installed upside down. I've done dumber things than that.

Good luck,

OK-AL

The thermostat is the first place to start.

That's exactly the reason I don't like those cheap parts houses.

Maybe he's just got one of those "fluttering" thermostats that can't hold a gradual temp adjustment.

Darned outfits will drive ya crazy sometimes. :>)

Allan

Had a cheapo one time that had the wrong impeller on it. Should have been sold as a v-belt pump, because it totally turned backwards with the serpentine.

Allan

Never given this much thought, but does the pump pull water out of the bottom of the radiator? Then if I unhooked the top rad hose, would it spray water out of that hose when I bumped the engine over?

Thanks Allen, something to think about. I'll be more than happy to put a different pump on if I know this one is bad.

Does the fan clutch screw on (one big thread), or does it have a 4-bolt flange?

I was thinking it would be new enough to be the screw-on fan clutch, and if that fits, it SHOULD ensure you have the correct water pump.

If the fan clutch bolts on with the 4-bolt flange, it's POSSIBLE you were sold the wrong rotation water pump, made for a "V" belt setup, which, while it will still pump, would do so with less pressure and flow than the correct water pump.

I did take the top hose off the radiator and started it up. It then dawned on me I won't get much of anything till the thermostat opens up. Just for the he!! of it, I did run a new wire from the thermostat post over to the ground screw on the inside of the fender---nothing changed. Of course I have no idea what those wires ground in the first place.

Think I'll try another pump and if that doesn't clear things up, I will have saved myself nothing. It was in the dealership getting a broken distributor gear (?) fixed. They noticed the pump leaking and estimated $420 something labor included. I said I could do the pump..... Oh well, Thanks for the help to this point.

Of course, there's always the possibility there's something real weird wrong with the new pump.

2.) Did you disturb any ground wires attached to the engine in the thermostat area?

3.) (And most likely), the new thermostat is the root of the problem. For a couple of bucks more than the generic unit, you could get and OEM thermostat. For the newer vehicles I work on (Ford and Chevy), I have better luck with the genuine OEM thermostats.

Changed pump on Thursday, and have about 30 miles on it since then. Don't recall disturbing any wires doing the pump. Then I had the temp gauge problem , and that is why I decided to change t'stat.

Changed the t'stat today (napa), and there are two wires connected to the front stud. Half a$$ed cleaned the stud before I put it back on. But it still acts like it did before I changed the stat.

I'll go back and look for a ground or any other wire I may have disturbed. I just don't understand how changing a water pump would cause all this. If there was a problem with the pump, it actually would be hot. T'stat didn't affect anything. I did replace the cap (15 lb) and that didn't do anything for me either.

The fan clutch works ok too, however, I haven't stuck my finger in that yet.....