3Bean is Hot! (Cooling issues)

[POS Racing]

Maybe it's time for a new rad!

Don't you already have a replacement metal radiator? You can get those (as well as the plastic ones) reworked at a competent radiator shop.

Actually, I don't know if it's a replacement...

Reworked?

Isn't it metal? Mazda OEM radiators were plastic.

[Treibenschnell]

Maybe it's time for a new rad!

Don't you already have a replacement metal radiator? You can get those (as well as the plastic ones) reworked at a competent radiator shop.

Actually, I don't know if it's a replacement...

Reworked?

Isn't it metal? Mazda OEM radiators were plastic.

Well... I've never really noticed!

I know it has a plastic drain plug (which struck me as odd... but appropriate if the rad itself is plastic...) I'll take a magnet to it later and see if it's ferrous.

[POS Racing]

Here is a picture (of my car) showing an OEM radiator.

[Treibenschnell]

Ooooohhhh! Pretty...

The radiator looks exactly the same. It must be plastic as well?

[onething]

I'll take a magnet to it later and see if it's ferrous.

Let us know if it sticks to the plastic or aluminum parts. If so, you definitely have a buildup problem

[Treibenschnell]

I'll take a magnet to it later and see if it's ferrous.

Let us know if it sticks to the plastic or aluminum parts. If so, you definitely have a buildup problem

No kidding!

[Treibenschnell]

According to this... the whole process is fairly simple...

And here I thought I had done it incorrectly... although I didn't do the Prestone flush stuff.

[altiain]

Hmm.... I flushed my radiator and changed the cap at the last tech day, changed the t-stat last week, and I'm still getting boil-off in my overflow tank occasionally on a really hot day if I park it after running the a/c. Supposedly NAPA sells a "Stant" cap (part #703-1406) with a higher pressure rating than stock (Part # stolen from the garage section of the pointy board). I think I'm going to try this, and if that doesn't fix it I'm going to buy a new radiator, as I noticed none of the student's Miatas I was in this past weekend ran hot even with the a/c on between runs with only about 5 minutes from one to the next.

[POS Racing]

The OEM Miata cap isn't the best cap around, I change my yearly or when she gurgles whether comes first. I don't like the ideal of putting a higher-pressure cap on the radiator since Yoshi designed it to run at his pressure with a PLASTIC radiator!

Danger, Danger, Danger!

[Treibenschnell]

The OEM Miata cap isn't the best cap around, I change my yearly or when she gurgles whether comes first. I don't like the ideal of putting a higher-pressure cap on the radiator since Yoshi designed it to run at his pressure with a PLASTIC radiator!

Danger, Danger, Danger!

You mentioned gurgles... is that a sign that the cap is going kaput? Mine's been making noise like there's no tomorrow!

[Treibenschnell]

Also, can you pick the caps up at Vato-zone or should I order via Mazdaspeed?

[POS Racing]

The OEM Miata cap isn't the best cap around, I change my yearly or when she gurgles whether comes first. I don't like the ideal of putting a higher-pressure cap on the radiator since Yoshi designed it to run at his pressure with a PLASTIC radiator!

Danger, Danger, Danger!

You mentioned gurgles... is that a sign that the cap is going kaput? Mine's been making noise like there's no tomorrow!

It is a sign! Hey Kestrel what were your results upon a cap change? I know yours was gurgling at the S2K event before last. It's a cheap & easy fix.

[Treibenschnell]

The OEM Miata cap isn't the best cap around, I change my yearly or when she gurgles whether comes first. I don't like the ideal of putting a higher-pressure cap on the radiator since Yoshi designed it to run at his pressure with a PLASTIC radiator!

Danger, Danger, Danger!

You mentioned gurgles... is that a sign that the cap is going kaput? Mine's been making noise like there's no tomorrow!

It is a sign! Hey Kestrel what were your results upon a cap change? I know yours was gurgling at the S2K event before last. It's a cheap & easy fix.

Ok... cheap and easy... but where? I was gurgling at the last auto-x as well... not good.

[bio243]

i aluded to this in an earlier post, but i'm going to reiterate my story. a few months ago i was going to my sister's house in carlsbad NM. when you get way out in west texas the speed limit goes up to 75 and the roads are flat and straight. you can manage to shave an hour or so off the overall trip with a watchful eye and a heavy foot. (besides it's about the only place i know with enough room to see what it will do at triple digits.)...anyway somewhere between andrews TX and eunice NM in the middle of the desert i look down and notice that my temp gauge is pointing at 3 o'clock...not good...push in the clutch, turn off the engine, pull over...after much testing and troubleshooting i determine that it is either my thermostat or my radiator. fortunatly it was the thermostat. after a quick modification (pulled the thermostat completely) i was on my way again (with an eye on my temp needle) and made it the rest of the way to carlsbad where i could find an autozone and buy a new one. tons of fun on the side of the highway

[Kestrel]

Hey Kestrel what were your results upon a cap change? I know yours was gurgling at the S2K event before last. It's a cheap & easy fix.

It fixed the problem... no more gurgles.

[Treibenschnell]

Hey Kestrel what were your results upon a cap change? I know yours was gurgling at the S2K event before last. It's a cheap & easy fix.

It fixed the problem... no more gurgles.

Where did you get the radiator cap at?

[Kestrel]

Where did you get the radiator cap at?

Autozone on Preston, north of Lebannon, near the Albertsons. I just asked at the counter for a cap to fit a 1999 Miata, and he handed it to me. I think it cost $2.99 or something. Nice cheap fix...

[altiain]

Hmmm... the new cap I got from Autozone last week did not fix my gurgling problem. I wonder if it was a bad cap.

[Treibenschnell]

What is the gurgling anyhow? Is that the cap losing pressure allowing the coolant to boil out?

[TurboDuane]

Stock cap is rated at 12 psi. If your coolant gets too hot it will build to over 12 psi, thus the cap will allow coolant to escape to the over-flow, allowing the coolant in the system to boil. The purpose of the over-flow is so when the engine cools, the cap allows the coolant in the overflow to flow back into the radiator. Some of you (not all) don't have experiance with the older cars. They didn't have overflow containers, so in the summer one would have to add coolant fairly often as the radiator would overflow onto the road.

The higher pressure cap (mine is 16psi) allows the coolant to get to a higher temperature before it starts to boil. As water under pressure boils at a higher temperature than water that is not under pressure.

What I'm trying to say is that the boiling over may or may not be related to the cap. The boilover sound could also be caused by other reasons relating to improper cooling.