Koyo Radiator Failure
 

I recently heard the low coolant buzzer going off so I checked to see what was causing it. It seems to be leaking by the threads on the coolant level sensor.
From what I can tell, there seems to be a plastic insert for the threads that some how broke and will not allow me to unscrew the coolant sensor.

My question is, has anyone heard of this or had it happen to them?
If so, HELP!! Does anyone know where they sell replacement parts?

Get a stock radiator, and a stock clutch fan and shrowd. Nothing like this will ever happen to you again.

My wife's vert came with a Koyo. It just started randomly leaking at the point where the bars meet the end plate.

Not too impressed with Koyo at the moment.

I could, but then my radiator wouldn't be as efficient

koyo radiators are 100% pure aluminum they dont use a plastic threads for the level sensor. You sure its a koyo? Now the stock sender piece has plactic threads on it which i think its a shitty design, that could be your stripped peice.

Were you having trouble with the car overheating? If not, your efficiency is basically a waste (lower radiator temps do not make the engine run better).

Because the thermostat controls the engine temperature, as long as the radiator is adequate to keep the car from overheating, it is fully sufficient (a bigger radiator does not make a colder engine).

Actually, the under-engine pan and the skirts coming down from the hood latch make more difference for overheating than the radiator, as they channel air through the radiator at highway speeds.

I in the same boat with RevinRx7, I snapped the plastic bleeder screw on my Koyo, does anybody know any ONLINE store that sells Koyo spare parts?

There's a big KOYO stamped on the top of the tank, so I assume it is :dunno:. I didn't buy it, came with the car.
There appears to be a white nylon ring under the level sensor though, and it turns with the level sensor. The sensor neither tightens nor loosens.

If this piece were stripped don't you think the sensor would come out?

No. It came with the car. I have plans for the car and its a safety precaution

I've never heard anyone recommend a stock radiator for an rx-7. Usually people say thats the first thing that should go :p:

i have heard good things about the stock radiator, and more good things about the stock fan/ shroud. I hear more about over heating with e-fans and aftermarket rads that the stock setup.

Post pics of the broken piece so we cans ee what your looking at, might be more clear then.

Pics tomorrow

I did the same thing some time back. I just replaced it with a bolt and just used the same gasket.

i was having problems with my stock radiator on my TII so i decided to get a koyo and an e-fan. have to say one of the best mods ive done till today.

I had the same thing happen to a koyo. What radiator are you running J-Rat?

You actually sound like you have a completely different problem than I do. This isn't the bleeder screw.
I guess we both may need to find parts.

Something interesting you guys might want to check...

To the OP, it sounds like the sealing washer failed...



-Ted

i got an error on that ted....

It's a PDF file...

Do you have Adobe Acrobat Reader on your computer?

Here, I've converted it to jpg's...


-Ted

Yep I finally got it out today. The plastic threads on the Coolant level sensor were broken. Anyone know a decent place to find a new one?

mazdatrix

I've got the same problem, but mine is much less severe... for now. I can tell coolant is escaping but I have yet to have to add any more (9 months and counting).

Your local mazda dealer. Make sure to use a new gasket!

mine did the same thing.. had to take it to a rad shop to get it welded up

I like to install a sacrificial zinc anode with a new aluminum radiator or a new engine, as well as run a new block ground. The $10 anode is cheap insurance for your cooling system.

This is wrong. Aluminum is more reactive than zinc or iron. So your radiator is sacrificing itself to save your zinc.