View Full Version : Adding an Electric water Pump 95 Northstar

07-03-09, 06:39 AM
I am interested in adding an Electric water pump to replace or augment the existing water pump in a 95 STS Northstar. Has anyone installed one? Any recommendations for pump, fittings, plumbing?

07-03-09, 06:50 AM
Crickets... I've never seen that option considered or discussed here or for any car. What would you gain with an electric pump?

07-03-09, 07:57 AM
I've only seen electric water pumps on race engines. It's to gain that extra 0.00001 horsepower to get you to go down the track one thousandth of a second faster.

07-03-09, 08:36 AM
Save your cash. The "Kool Factor" isn't worth the heartburn IMHO.

07-03-09, 10:28 AM
:hmm: Why?

07-03-09, 10:53 AM
Not necessary and the specially manufactured piping and water pump housing changes would cost more than the car is worth. Do you know what and where the water pump is on a Northstar ??? .......and how it goes in and comes out ???

Have you looked at the Northstar water pump and bypass setup and determined that it all bears NO resemblance to ANY form of water pump setup in a timing cover on the front of an engine? An electrical pump would have to be some sort of part-time booster pump in the heater circuit, but no room, no power gain whatsoever, and what for ??? Bling ?? Look what I got ???

07-03-09, 04:15 PM
I am quite familiar with the hydronic system utilized in the N* system. I am well versed in where the WP is located, its removal and installation, thank you.
I have an idea for a unique product, and I would like to validate my theory. It would be a great help if someone has some information about actually using an electric waterpump in this configuration. Thanks in advance.

07-03-09, 04:40 PM
.................lotsa luck, and again the prime question: Why ?? The installation would gain nothing in exchange for a decrease in system reliability.

(BTW - In all the time CF has been in existence, no one has successfully installed an electric WP in a FWD Northstar drivetrain. MAYBE in a sand rail or some sort of hybrid kit car, but not in a daily driver.)

07-03-09, 04:47 PM
Yes, injuring minds want to know.

07-03-09, 05:26 PM
Patience fellow CF members...patience...and the sooner I find out some plumbing implementations that have been tried, I shall certainly share sooner , in the mtm I will be researching and evaluating on my own....as this should be of interest to a few members...

07-03-09, 06:30 PM
I remember the guru at one point saying something like, at 6000rpms the stock waterpump will fill two 55 gallon drums of water in one minute (probably not his exact words, correct me if I'm wrong).... That's pretty impressive if you ask me. I don't know what you're going to gain with an electric waterpump. They're normally just set to high speed for racing because it needs to be able to disperse the heat of WOT quickly.... But in a daily driver, I suppose you would only lower the normal engine temperature. Which would cause the car to constantly run rich. Which would cause spark plug fouling, burned valves, and fun stuff like that. This is pretty close to being equivalent of running the engine without a thermostat (except that in a northstar it's possible to actually overheat by running without the thermostat).

So... Why are you trying to do this? What is there to be gained?

07-03-09, 07:01 PM
I am intrigued Krash...do tell why a N* would overheat without a thermostat?
Is this based upon some heat transfer properties? Interesting do tell....let me know more.
Regarding electric water pump, why must it be only run at full speed?
I also do not understand why a richer running engine would have burnt valves? It sounds like I could learn a lot here in this forum.
This enquiring mind would lie to know more...


07-03-09, 07:34 PM
Stop being such a condescending idiot and learn something about Northstars.

Krashed is trying to tell you that the N* loves to run hot - 200 degrees or so, and running it colder will upset the temperature controls in the PCM. You know darn well that the temperature controls have absolutely nothing to do with heat transfer - that's just your smoke and mirrors showing.

Yes, rich fuel/air mixtures create cool combustion chamber temps while lean mixtures burn valves.

The bling of an electric pump is totally wasted in a Northstar. Cutesy on a street SBC or Ford 302, but WHY ???

07-03-09, 08:30 PM
....do tell why a N* would overheat without a thermostat?Do tell? You would do well to lose the attitude.

Below is a quote from a three or four year old posting by a qualified and respected former forum member.

And if your question above is sincere, and you are really do not know the answer, I suggest you are facing some time-consuming research before returning to the water pump question.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * *
The Northstar has the thermostat on the water pump
inlet. Most thermostats you are used to on other engines
are on the exit side of the coolant from the engine, not
the water pump inlet side like the Northstar. In
addition, the Northstar has a large coolant bypass
passage to allow coolant to recirculate thru the engine
to minimize hot spots and maximize flow. Only a portion
of the coolant flow goes to the radiator. The thermostat
controls all of this besides just controlling engine
temperature. If you remove the stat and drive without it
the coolant flow will be totally screwed up and very
little will go to the radiator. There is a spring loaded
paddle on the Northstar stat that controls the bypass
flow independent of the thermostat position or coolant
temperture. Without the stat this paddle is missing and
the bypass port is wide open. You do NOT want to run a
Northstar without the stat. It will cause it to run hot
and overheat.

07-04-09, 02:07 AM
The guy that wrote that was the leader of the GM Powertrain design team that was responsible for the NorthStar cooling system.

07-05-09, 02:46 AM
Electric Water pump from Cadillac Hotrod Fabricators:


We finally received the item we needed to remove the water log from the back of the Northstar engine. We have worked with Meziere to develop a remote mounted electric water pump with a thermostat built in. This allows the engine to warm up properly and run the heater!!

We already manufacture a set of cnc plates that mount over the water inlet and outlet on the rear of the block. Have your hose sizes coming off and back to the radiator ready when ordering.

List $693.77 Our Price $682.15 for black. Fittings $18.00 each, specify red, blue or black

1-1/4", 1-1/2", 1-3/4" hose and AN-10, -12, -16, -20, -24

Pumps also come Polished, blue, or red, anodized, with an up charge.

07-05-09, 10:21 AM
The OP asked for electric water pump recommendations for a '95 Cadillac STS with a Northstar engine. There are no recommendations for that vehicle/engine either here or from CHRF.

You can do anything you want to an engine in a sand rail or a custom Fiero package - all it takes is time and money. The FWD sidewinder engine in a Cadillac is a different story.

07-05-09, 10:41 AM
all it takes is time and money.
And apparently lots of it.

07-05-09, 11:03 PM
Yes, rich fuel/air mixtures create cool combustion chamber temps while lean mixtures burn valves.

Whoops.. I had it backwards. :p

07-11-09, 10:42 AM
Thank you IXSLR8, I appreciate you taking the time to answer the question I was asking.

Submariner, you are funny...your self confidence needs no crutch! I did not understand some of the comments Krashed had made and requested clarification. Conflicting information piques my interest as there is always something to be learned....by those that are interested in learning at least. The information posted about removing the thermostat was contaradictory to what I have witnessed, and wanted to understand more; especially if there was some theory or explanation that could be shared. You apparently feel better by calling people names, making sardonic comments, ....and demonstrating your keen insight and vast comprehension.
For the other individuals here on the forum, the experience that was conflicting is as follows. A friend's 95 ETC N* had experienced a problem where his thermostat would not open. This occurred in the not so distant past in March on a Sunday eve. The thermostat when subjected to 212F boiling water would not open. He needed the car for a trip the next day and he requested that I put the engine back together w/o the thermostat. Although I suggested he wait til the AM, I did as he asked. After putting it all back together and filling with coolant, the vehicle drove fine except for minimal heat (passenger compartment heat) and longer warm up times . He drove the car for several weeks covering several thousand miles highway and city bumper to bumper, w/o any other observed issues. He finally came back to me end of June to install a new thermostat. I did and all was fine. I used the car over the weekend w/o the thermostat and similarly did not notice any problems except for running cooler than normal, but never overheating.
I checked the new thermostat and it opened in advance of the water boiling. I installed it and he is driving it currently. I don't suggest driving a car w/o a thermostat for all the obvious reasons. A N* doesnt like to run HOT, it likes to run at the temperature it was designed for. Any engine needs a properly functioning thermostat to achieve its warmup characteristics, heat, emissions, performance, etc....I wanted to share my empirical observations which is contrary to the statements made in this thread.
I look forward to sharing and learning more from the members of this forum as I believe thats what this forum is for as opposed to flaming. We all ask questions in different ways in the interest of learning.
Thanks again for the information.

07-11-09, 11:00 AM
................better than being a condescending idiot.


05-07-16, 09:56 PM
these engines do not circulate coolent the pumps cavitate and flow stops thats why the heaters stop puting out heat. thats why hes asking about an electric pump. not for the bling factor

05-08-16, 09:34 AM
This thread is 7 years old.

If the purge line is clear (and the HG is not leaking), the WP will pump coolant all day long with no problems.

05-08-16, 10:25 AM
These engines do not circulate coolant when the pump cavitates and flow stops due to either air, gas or low coolant level. That's why the heater stops putting out heat. That's why he's asking about an electric pump. But, if the Northstar cooling system is clean, with a properly functioning water pump drive system, the factory water pump will correctly cool the engine in Saudi Arabia at noon at 130 mph in August.

Fixed .................

.......... and, as long as we are dredging up ancient info, a FWD Northstar thermostat is set to begin opening at 188 degrees and is fully open at 206, so a properly functioning system will maintain 190 - 205 degrees all day long - UNLESS you are sitting in heavy traffic with the HVAC (A/C compressor) OFF, in which case the coolant temp will rise to 224 degrees, fans go to Slow, the engine cools to 213, fans turn Off, the cycle repeats. Normal.

The bars or ticks on other FWD Northstar car temp gauges correspond to the ones on this annotated 2002 Seville gauge..........

05-09-16, 08:18 PM
My electric water PUMP is a Mezire 55 gallon per minute free flow. I do not run the original water system. I send cold water to the heads first then thru the block to thermostat then to top of radiator down flow 18" X 20" walker 1932 ford radiator, have a heater bypass at the pump, and a overflow canister. Runs at indicated Stewart Warner electric temp gage 195-205 with a stock type thermostat. It shortened up the engine length about 6 inches to fit in the chassis, it is by no means nothing but a custom deal, not a FWD or a RWD NorthStar chassis. Just some info.


12-07-16, 08:35 PM
I can only speculate that the original poster was wanting to implement an electric water pump to try to solve the head gasket overheating issue by providing a constant flow of coolant even with exhaust gas air bubbles.