[1987Firebird]

Hey all,

Have this problem that's driving me up a wall, had a cheap parts store water pump on my engine that was doing a decent job at best temps were around 210-220, i have a 2 core aluminum radiator dual 12inch fans with a shroud, a high flow high pressure 180 T-Stat, Autometer Phantom Gauge and new sending unit

So i finally got around to purchasing a emp stewart stage 2 pump hoping it would solve my problems but it's only made it worse.. Temps jump from 250 to 180 to 160 back to 250+ in the course of a few miles depending how high i rev the engine, really don't know what it could be being that everything is new

I've purged the system several times let it run with no rad cap to get rid of the air and popped the heater hose fitting off the pump making sure no air was trapped in there..

Anybody have any suggestions? i had summit send me a new pump but before i go through the hassle of putting that one on has anybody experienced this before? Ive never had this problem even with the crappy parts store pump

Currently the sending unit is in the intake, should i move it to the head?

Thanks in advance!

[DoubleVision]

What belt system is on the vehicle? While many perfer the sending unit in the intake I perfer it in the head, that way I know whats going on temp wise where all the action is taking place.

[cdminter59]

Where the sending unit screws into the intake clean it good and do not use teflon tape on the threads. Make sure all ground straps are connected. One from engine to body, one from engine to frame, and one from negative battery cable to engine block not altenator bracket. If it still does not work try another sending unit. If new sender does not work replace the guage.

[1987Firebird]

Regular 2 belt system nothing crazy nor do i have A/C..Sending unit is new but Asfar as the threads on it all i put was some black RTV silicone..

However i do have March Underdrive Pulleys would this effect the pump?

I'll check the grounds tomorrow morning

Thanks guys appreciate it

[matt406]

maybe the water is passing through the radiator to fast to cool down try a stock style water pump. im just saying because my friends 65 malibu had a similair probelm and fixed it by going to a stock water pump. he had aluminum heads, aluminum radiator, doule electrice fans, high flow water pump fixed problem by going to stock water pump. also try a thermostate that opens up at a lower temp. or maybe you have a thermostate thats not opening because of an air pocket

[oldbogie]

Originally Posted by 1987Firebird

Regular 2 belt system nothing crazy nor do i have A/C..Sending unit is new but Asfar as the threads on it all i put was some black RTV silicone..

However i do have March Underdrive Pulleys would this effect the pump?

I'll check the grounds tomorrow morning

Thanks guys appreciate it

Get rid of the under drive pulleys!!! They turn the pump too slowly thus not enough coolant flow.

The whole idea behind under drive pulleys is totally bogus on the street. The fabulous horsepower savings only (and I mean ONLY) happens in the high RPM range. Power extracted by the water pump or any other accessory for that matter is always related to RPM and of course load on the device (alternator/AC). The water pump is a place where you can't control the load; that simply goes up with RPM. It is a rather parabolic curve laid on its side where there is a mathematically power (squares/cubes) kind of thing going on. But the power extracted at idle is very tiny so it takes a lot of RPMs before you start seeing this magic 20-30 horsepower gain (5-6 thousand). Think of your washing machine as a parametric data point, it empties a 20 gallon tub in less than a minute with a pump driven by a 1/3 horsepower motor. That's plenty enough and then some to cool a 350 at idle. So this whole idea of getting back 20-30 horsepower from idle up is nothing but advertising non-sense.

Another grind I've developed is Eagle's shiny coated crankshaft where they show this 30 horsepower jump that's linear from idle to 6000 RPM. Anybody that understands engines knows this came out of the advertising office not the dyno room. The add staff probably got a data point from 6000 rpm and just drew a parallel line to an existing dyno chart. It's not so much they lie as it is they just don't know. Their lunch is spent in a cool bar over dry Martini's not sweating over an engine in a hot dyno room with a stale half eaten peanut butter sandwich in one hand and a cold cup of last night's left over coffee in the other.

Bogie

[1987Firebird]

Well the problem's been fixed, silly thing is i don't know if it's the ground or the new water pump.

I'm betting it was the ground lol i found the bad ground asoon as i put the new pump on, ground from the motor to the body was sparking and loose.

Running at a steady 180, couldn't be happier.

Thanks everybody seriously appreciate all the help and suggestions!