OCD engine cooling

ok, first off, Im not a master ASE tech, i don't work for Mazda, the following is just an experiment I am trying.

Our trucks are "notorious for having headgasket issues."
Every vehicle I've ever gave up on and sold has been from a cooling/head related issue. so, I'm gonna try and be as anal retentive about cooling system specs on my truck as possible, and see how long i can I can stave off a headgasket repair.

actual engine mileage unknown, approx 60-90k on crate motor. odometer was at 234,144 when i got it, so if and when i have overheating issues, i will be going of that mileage. This is a carbed 87 B2200. i dont know if B2000 will have anything different coolant wise, and 2600 is either Mitsubishi built, or based on, so this wont apply.

Again, this will all be my opinion based on what I've researched. I know everyone's driving habits and climate will be different, so i can't guarantee results. I'm just trying to see how long i can avoid the inevitable by going above and beyond to keep everything at factory specs with afforable parts.

When i first got it, the temp gauge didn't work. Can't put off impending doom if i dont know how hot im running it.

part is called "coolant temp sender"
its located on the bottom of the thermostat housing. 1 nipple pin connector. I dont know the wire color off hand cause mine was spliced into several times.

testing wiring:
(i have heard people say dont do this. as far as i know, if done right, it will not cause harm.)
NOTE: WHEN YOU DO THIS, ONLY TURN THE KEY ON FOR A SHORT TIME. JUST ENOUGH TO SEE THE GAUGE MOVE. I DONT KNOW ABOUT MAZDAS FOR SURE, BUT IVE HEARD IT ON OTHER VEHICLES TOO. IF YOU LET THE NEEDLE PING ALL THE WAY TO THE TOP, DAMAGE IS LIKELY TO OCCUR.
key off, engine off. shorted the wire to ground.
get in car, turn key on. if gauge moves, then its the sender. mine too some wire repair before it would move.

part replaced:
Mazda Coolant temp sender:
Oreillys:
brand: BWD
PN: WT515

Engine took forever to warm up, so i guessed someone had left the thermostat out.

read around on here and mazdatruckin, then looked at autozone, oreillys, and advance online. all sources gave me the following mutual answer:

the factory spec on our thermostat is 192*

I know there are other temperature choices, but if i dont fully understand what im doing, i dont feel like taking a chance. Ive installed a lower temp thermostat on another vehicle i had in the past, and it seemed to cause even more cooling system issues, so i chose not to reinvent the cooling wheel. I want to play it as safe as possible and see if it pays off.

I went with a Murray's Ultra stat, part number 15869 from Oreillys.
It was higher on the price range, but not dealership high, and it was rated at 192*, not 190, not 195...
It supposedly has a safety feature where if it overheats once, it will lock the thermostat wide open to prevent more problems. If and when i have an overheat later, I'll update if it works.

patience helps here... or another vehicle. i cleaned mating surfaces, installed thermostat, sealed it, filled coolant, ran it, and sprung tiny leaks behind the thermostat housing...

the second time, recleaned housing surfaces, reinstalled, spring side into motor, jiggle pin up... resealed housing. WAITED A FULL 24 HOURS for the sealant to cure before adding coolant or running/pressurizing system. so far, no more leaks. got a small tube of "thermostat housing sealant" the second time. smaller tube, cost less than the blue RTV also.

While I'm part swapping, might as well do a new radiator cap. the seal on the old one looked older. not bad, but for a few bucks, not worth the risk later.

again, reading between here, mazdatruckin, and all 3 part stores, came up with:

factory spec on our radiator cap is 13PSI


went with Murrays PN 7513 from Oreillys.

rated at 13psi, and a normal cap.

I have tried those safety vent caps in the past... the ones with the red lever to discharge pressure before opening, but have had bad luck with those leaking. so went for regular design.

the correct cap is important. i didnt pick 13psi, someone at mazda did. but our entire cooling system runs off the assumption its at 13psi. when you increase pressure, you raise the boiling point. so our cooling system was designed to get right up under 13psi to operate at its prime. above 13 is vented out into overflow tank, then syphoned back as the system cools. (why its worth having an overflow tank, and having coolant in it)

if the cap leaks or doesnt work, the boiling point of water/coolant drastically drops. that causes overheating. any pinhole leaks anywhere in the system cause the same problem as a faulty cap. thats why one tiny leak can turn into a new headgasket and or head if left unchecked.

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COOLANT:
(and again, this is all my research and my opinion, you dont have to do what i did, im just seeing how it works out for me)
1 gallon PEAK long life concentrated coolant
1 gallon distilled water
1 bottle of radiator flush

B2200 cooling system is 7.9qts with heater core hooked up

I asked on here and mazdatruckin, and got similar answers. 50/50 mix of whatever... that may work fine.
BUT
Knowing our trucks are prone to headgasket and overheating issues, I didn't want to take a chance on something i wasnt sure would work good.
I googled mazda coolant, and found some more articles on various sites. the mazda3 guys seemed extremely OCD about which coolant they would use. maybe minitruckers are more laid back than rice jockeys. either way, for under $20, Id rather know for a fact what I'm doing works, than leave a head up to chance that it might work.

The Mazda 3 guys found 2 options for mazda coolant:
Mazda FL-22 coolant pn: 0000-77-508E-20 "extended life"
or pn: 0000-77-501E-02 "long life"
from mazda dealership
FL-22, as in diluted version, is identical to
Motorcraft Specialty Green, Ford part number VC-10-A. (50/50)
Motorcraft Specialty Green, Ford part number VC-10-A2.(concentrated)
from ford dealership
those being the best 2 options for newer mazdas which are apparently more sensitive than older vehicles...


"The green in most Japanese cars contains no silicates, so it's not the same as the green in the parts store."
"Using conventional North American green coolant in a Mazda is a bad idea. Even German (BASF) coolant technology as embodied in G-05, which contains silicates and no phosphates, is a much better choice than conventional North American green for vehicles with aluminum blocks and aluminum radiators. But a genuine P-OAT coolant, particularly a second generation P-OAT coolant like Mazda FL22 or Motorcraft Specialty Green, is the best choice."
older mazda, and most japanese cars need a "silicate free coolant"
most silicate free coolants just happen to be green, but color doesnt make it right.

"The only aftermarket P-OAT coolants are Japanese OEM coolants from Mazda, Toyota, Honda, and Nissan, Zerex Asian Vehicle coolant, PEAK longlife, Peak global lifetime and Motorcraft Specialty Green Engine Coolant"
(there may be other silicate free coolants that work, this is just the list i found so far)

all coolants have ASTM standards on the bottle:

if you are bored enough to look there, you will find what a specific standard means. some of the ones on the bottle i got were detailing the following
silicate free coolants are designed for mixed iron and aluminum engines. a silicate coolant supposedly doesnt provice enough protection for aluminum parts.
other standards were for things like water pump lubricant. so some coolants apparently keep our water pumps spinning free, while others meant for og v8 timing chain cars wont provide this lubrication...


drained radiator. filled with prestone radiator flush and water.
followed instructions on the bottle, ran it, rinsed it, ran it, rinsed it...
actually rinsed the cooling system til nothing but clear water came out
(something ive never botherd to do before)
washed out overflow tank.
filled engine and overflow bottles with coolant. used gallon up. added distlled water on top of both to finish filling (7.9qts total)
ass down, nose up on juice got radiator cap as the highest point. if your suspension doesnt move, park on a hill, or read alternate bleeding places on this site...
bled all air out. put on cap, op ck good.

I chose parts that stated they worked within factory spec. and i even used distilled water. this may all be overkill, but if it prevents me doing head work later, Ill be happy i took the time...

fan clutch spins too freely, needs replaced

Also, My timing belt is starting to show teeth shadows through the backside, so a few more paychecks, and timing belt and waterpump will be done and info added here too...

Fan clutch came in today.


I priced them at autozone, etc. most were really damn expensive, like over $100.

I ordered it from rockauto.com.
HAYDEN Part # 2562 for manual transmission

available in local stores for way too much. $39 at rockauto.
went with the Hayden one after looking at the info link on rockauto.

hayden cooling parts have 5 year warranty, so i took that as hayden knows how to make cooling system shit, where some of the others may just be like nike trying to make skate shoes.... may work, but they werent confident enough to do more than a 30-day warranty on their own part, so i passed on other options.

when i installed fan clutch, noticed the belt way way too loose, and the alternator was maxed out to the left. got a new belt while i was out today.

while putting the belt on after driving home, halfway through belt change, coolant decided to start pissing out on me.

cant tell if its from the thermostat housing, or the upper radiator hose...
did get about 2.5 more turns on the hoseclamp, so really hoping its that, and not housing seal round 3.

just refilled and bled the air out (and yes, refilled with equal amounts of coolant and distilled water. Im trying to keep my experiment as pure as possible). will probably update tomarrow once im sure of leak location...

Nice thread man, keep up the good work!

turned out it was the hose clamp.
i read somewhere you should replace hose clamps with new ones when you remove them. until now, i thought that was a dumb idea and a waste of money...

the clamp would let me tighten it, but drive a bit, and checked it when i got back home, and its loose again.

also noticed upper radiator hose was really swollen looking with pressure. felt spongy too. so got a new upper radiator hose when i went for clamps anyways.

compared to the new hose, the old one had grown about 1.5 times its size between the clamps.

read a decent article explaining how to check hoses:


I guess my lesson today is dont be stingy and buy new hose clamps.