Paradox

iTrader: (1)

i'm running my car with no t-stat cause i'm cool, it's been sitting for almost a year now and when i start it up, seems that the engine gets rather warm but the radiator is not that warm at all to the touch.

i just tried some block sealer on my engine because i knew i had a leak in the coolant system somewhere and read of it working wonders in many other cases.

i just replaced my water pump a month or two before it sat. so it should still be functional. this block sealer says it will lubricate the water pump right on the bottle, whereas i've heard from others that it can seize it. mine isnt seized, i can spin that pulley freely with my hand. i'm wondering if maybe the temp sensor is wrong itself, since it reads from the top of the radiator, correct?

if i let my car idle for a few minutes the dash gauage will go almost to the halfway mark, but if i get out and touch the radiator its normal temp, engine feels warm, but i guess i dont normally touch the engine to compare.

any idea's?

i'm trying to save this motor, atleast for a little while til i can strip my SE of everything i need and swap its motor into the GS.

Rx-7Doctor

iTrader: (13)

1). Never run a rotary engine without a T-stat.
The t-stat is like a regulatory valve. In order for the engine doolant to drop in temp it must stay in the radiator while the ram air or fan is cooling it. This is while the coolant in the engine is carrying away the generated heat. When the temp gets to it's predetermined temp it starts to open up and then is fully open at another temp. It now takes the coolant that has been cooling in the radiator and recirculates it thru the engine to cool it back down.
When you do not have a T-stat the coolant that is trying to carry away the generated heat keeps picking up more and more heat becuase it does not spend anytime in the radiator cooling off.

The temp is not read at the radiator, that is the low coolant sensor you are looking at. The coolant temp sensor is on the side of the rear plate just to the left of the oil pressure sender.

If your coolant seals in the engine are bad because you overheated it too much at one time block sealer will do nothing.
Block sealer works on headgaskets, cracks in blocks and other gaskets.

Now if the fan clutch is not operating properly and you let the engine idle for an extended period of time the temp will also rise. If the temp does not go above the 1/2 mark then there is no damage. With the proper t-stat, a working fan clutch, anon slipping belt, the proper mix of coolant/water, and a good flowing radiator, the temp should be less than 3/8 of a way on the gauge. Most of the time it should be below that.

trochoid

iTrader: (6)

Did you feel all over the rad? If the rad was partially blocked due to corrosion, the block sealer can seal the tubes. This reduces the rad's efficiency, leaves it showing cold spots and some hot spots.

flight_of_pain

if your not running a t-stat you MUST block the bypass hole or no coolant will be circulating through the rad, it just loops through the block.

isaac

trochoid

iTrader: (6)

Good point Isaac, that's also another reason to use an oem only thermostat because some of the aftermarket oneswill not block off the bypass. It's one of the odd things Mazda did on thier cooling system.

Paradox

iTrader: (1)

yes bypass is blocked. as for the fan clutch i just swapped that, so it is fine now.

nice to know the proper location of the coolant sensor though. i wired up pretty much all of that manually.

why dont you guys have any faith in the block sealer? i've read so many threads about it working out for years.

i know the only alternative is a rebuild but i have a spare motor, i'm just trying to get this one working as is for the time being.

thanks for the input. you guys are always a wealth of info.

bliffle

ALWAYS use a tstat and always use an OEM tstat. Same goes for the radiator cap. you can get both from mazdatrix.

The correct sealer correctly applied can temporarily fix some minor cooling system leaks. I've done it with 12As that have been temporarily overheated and it can last several months. The correct sealer contains colloidally suspended copper powder and filings and I find it in a clear plastic bottle called "CRC" sold locally and looks like a clear liquid with copper settled at the bottom. The correct application (not the application given on the bottle!) involves getting the interior of the cooling system ultra-clean by repeated use of degreaser and water rinse cycles and then the introduction of the sealer followed by properly setting that sealer so it doesn't wash out. To get it to set properly it's heated to operating temp then allowed to cool down a few hours, being careful not to blow it tout of the leaks by revving the engine.

I use a plastic TEE from the Prestone flushkit ($6) to faciltate the numerous drain and refill cycles. It's inserted into the lower heater hose from the radiator and capped by a plastic cap.

Sometimes (rarely) you have to replace the waterpump after a while. I suspect that the cleaning cycles washout the bearing lube.

Later, when you disassemble the beehive (and usually it's a beehive 12A because the beehive leaks deteriorate the heater hose that runs underneath it resulting in sudden coolant loss, overheating, and internal oring frying) you'll find the 4 orings brittle and broken. Same for the 2 orings in the manifold gasket.