I'm about to flush my coolant. It's been using Prestone that's not pre-mixed. What are the advantages/disadvantages of using pre-mixed coolant? What do you think is the best coolant to use for an FD.

 

I use the green, long life coolant that is sold under the Mazda label at Mazda dealerships. I've very satisfied with it. There should be a brochure at the parts counter that talks about its claimed advantages. I've been told that it came as the original fill in my '95 FD.

 

searching for this exact question led me here.

just curious, is there a coolant that actually runs cooler than others? ive been running prestone 50/50 already mixed, and then adding more water to make it around 70/30. but im not sure if its the best.

 

rx7.com has some special coolant that they use but its expensive. They say it works best for our heat soaked engines http://www.rx7.com/store/rx7/fdengine_cooling.html

 

Best conventional coolant is the Mercedes green stuff. Next is the Toyota red.

None of the conventional stuff did squat for both of my prior motors in over 10 years. Corrosion and all kind of crap indicated by the 0.5 volts differential between the coolant and block. Both motors had warped housing.

I run the Evans NPG+ 5 years, 20K on the third motor w/o any issues using a 7 lbs cap. $42 per gallon. Almost no voltage differential between the coolant and housing. I also have an electric auxiliary water pump from a VW Passat circulating coolant out of the block after shut off.

 

What do you mean the conventional didn't do squat? You're blaming the coolant for the electrolysis? Sounds like you had some electrical issues.

As far as corrosion, what quality of water did you mix with and how often did you change the coolant?

 

Take a multi-meter. Set it to 1V resolution. Stick the red probe into the coolant. Stick the black probe to the engine block. Read the voltage.

Iron + Alumimnum + electrolyte= battery.

What do they teach kids nowadays in school?

 

I used distilled water with 50/50 mixture. Changed coolant annually for 10 years and 2 engines. Each engine lasted 45-50K. All had the terminal o-ring syndrome.

 

Apparently you were taught to be a ****. That doesn't have **** to do with electrolysis. Electrolysis has some similarities, but current is applied between the two metals, not created by their reaction with the solution. You know, anodes and cathodes... the **** they don't teach us "kids" nowadays.

I was just saying if you're having electrolysis problems, changing to a fancy coolant seems like a bandaid. On top of that, I was having a hard time understanding what your problem is specifically.

 

So, it's the coolant's fault? Even though tons of irons have lasted 4 times longer than that in FC's and almost as long in FD's?

 

I've always been told to never put red coolant into your rotary. I've been using plain old Prestone for years with no issues.

 

I like the original Zerex green. I like valvoline oil so may as well use their coolant

 

Plain ol' Prestone Green, w/ distilled water 70/30, no water wetter, no issues.

 

i dont know about best coolant, but here is an interesting tidbit i just learned. Dont buy the premixed 50/50 stuff. I thought i was saving $2 on getting a kragen type brand, but it turns out, half the damn bottle is water!!! lol.

So by spending the extra couple of dollars you get Twice the amount of coolant, just need to 50/50 it yourself.

Marketing Owned me!!!

 

If you had the cash, id perfer to use the evens non-press. coolant it's well worth the money.

 

Thanks for the compliment. Being a **** is the nicest thing you can say. Much better than "he's a dick, as in dick cheney."

It is notoriously well known that "electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them." See Wikipedia.

Now, I never said that I'm passing a current to my motor. You're the one using the phrase "electrolysis." Are you that dense? Do you realize that in order to perform electrolysis as you infer to "some electrical issues", I would need to attach an DC source (e.g. battery) with the anode to the iron housing and a cathode to the alumnimum (or vice versa, take your pick).

What I am saying is that electron transfer (current =V/R) is generated (NOT inputted) by virtue of the dissimilar metals and the electrolyte (duh - water+eg coolant).

I changed to NPG+ not exclusively for electrolysis as you infer to "some electrical issues." I don't know why my motors failed in this manner so one area to address was the cooling system. Evans NPG+ seem to help even in the 118 degrees Arizona heat.

No thanks needed for bitch-slapping lesson I just gave you as I realize that you might be attending VCU, which as a former Hokie, I can attest that this school is not respected in Virginia for their curriculum in science.

 

Ever since I noticed the little electric auxiliary pump on my Audi TT I've thought it would be a great addition to the RX-7. How did you set yours up? The heater hoses at the back of the engine would make for a great pump inlet, but where do you have it dumping the coolant to? What about electrical controls for it?

 

Bitch slapping lesson. Couldn't have put it better myself.

I'm just going to stop, because you're obviously the kind of person that thinks this is a battle and not a discussion.

 

See https://www.rx7club.com/showthread.p...=electric+pump

The reason VW VR6 motor has these pumps is because the v-angle between the cylinders are about 15 degrees which make for very concentrated hot spots after shut down.

On my car:

Pump pulls coolant from the plastic pipe between the plugs, push into the heater hose through heater core out back into the inlet pipe near the lower radiator hose.

Relay connected to a temp sensor switch set at 200F. Almost five years now. Work like a champ, no temp spike to 285F even in Arizona 118F degree weather. Motor stills getting 455 mm of Hg on the PFC Commander.

Total cost about $160 and 2-3 hours of work.

 

There's also Racecool. www.racecool.com. I think I'm going to try it when I get a vmount.

 

There's a dearth of material on their website describing what the product actually is.

It *isn't* ethylene/polyethelen glycol, but nothing there says what it is.

 

Just wondering if it is alright to use RO(Reverse Osmosis) water instead of distilled water. What are the disadvantages?

 

Seems like it would be fine. As I understand it, RO is just a different process for removing minerals from water. But essentially it accomplishes the same thing as distillation.

 

I been using BMW coolant for years with great results. I have never had a problem with it.

 

This guy has it down....nothing else needed.



LAter