Boiling Coolant?

Can someone tell me why my rad fluid was bubbling (boiling?) today after driving it spiritedly in the middle of the day?

• Coolant level looks good.
• Is about a year old and a 60 H2O / 40 AF mix.
• Temp gauge stayed in the middle the entire time.
• It started bubbling after I pulled into the garage and turned the car off.
• Guess it could have been doing it as I drove?
• No leaks or overflow loss.
• I turned a fan on to run air throught the radiator and left it to sit and cool down.
• Drove it tonight and no problems or bubbling.

It was a rather hot day, perhaps the outside temps pushed the radiator fluid a bit and it bubbled... I've had it happen several times now. No overheating, but close enough to cause a slight concern.

When was the last time you replaced the radiator cap? It was the cure for my car.

YMMV.

Quote:

---

Originally Posted by POS Racing

When was the last time you replaced the radiator cap? It was the cure for my car.

YMMV.

---

You're the second person to tell me that. Time for a new rad cap.

Sounds like that should work. ;-)

A new radiator cap and t-stat should help.

Still, don't forget that after a "spirited drive", if you shit the car down and park it, the coolant stops circulating. It's not uncommon for the coolant in contact with the block to boil under those kind of circumstances, when the engine is really hot.

Quote:

---

Originally Posted by altiain

... if you shit the car down...

---

You do what? ;)

Mine boiled/gurgled one day last week after a 'spirited' drive home from work. Coolant, T-Stat and radiator cap are all less than 1 year old.

Quote:

---

Originally Posted by sammm

Mine boiled/gurgled one day last week after a 'spirited' drive home from work. Coolant, T-Stat and radiator cap are all less than 1 year old.

---

Same here... although I think if I replace my underbelly tray it won't happen as often.

Quote:

---

Originally Posted by altiain

if you shit the car down.

---

Quote:

---

Originally Posted by Treibenschnell

You do what? ;)

---

I don't think pooping on your car is going to help! :shock:

I'd try the Radiator Cap first!

You can switch to a rx-7 cap. That will bring you up to a 16lb system instead of a 13lb pressure

Quote:

---

Originally Posted by POS Racing

I don't think pooping on your car is going to help! :shock:

I'd try the Radiator Cap first!

---

Dammit! I need to detail the car now thanks to Iain! :oops:

After I hose off all fecal matter I will buy a new radiator cap.

Any idea on what year RX-7?

I know it's only a 3 psi increase but can the OEM plastic radiator handle the task? :scratch:

Quote:

---

Originally Posted by POS Racing

I know it's only a 3 psi increase but can the OEM plastic radiator handle the task? :scratch:

---

I thought consensus was that it couldn't deal with it... that Miata OEM was best.

Sorry, I've got an aluminum. I keep forgetting about the stock limitations.

I have an aftermarket all metal radiator. Anyone know what year model RX-7 rad cap fits the Miata?