Overheating over 60 mph

Printable View

08-07-2013, 08:16 AM
orbit1

Overheating over 60 mph

Hey peeps I have notice my 95 Miata is heating up when I drive between 65 and 75 mph. Once I reach 65 mph the temp gauge started to rise to 1 o'clock position then to the 2 o'clock position. I slowed down to 60 and the temp started to drop. Slowed to 55 mph and it dropped to normal temp. The AC works just fine, there's no coolant leak anywhere and oil level has not dropped either. Perhaps I need to replace the Water Pump, the Thermostat or the Head Gasket... I'm open for any suggestions.. Thanks guys ::Banana::::Banana::
08-07-2013, 08:26 AM
OZMDD

We need to discuss proper use of the dancing banana, this post wasn't even a single banana, much less a double. When posting, ask yourself: "if I were a fruit, how funny would this post seem?"

FYI, :confused: would be the correct emoticon for your dilemma. Good day, sir.
08-07-2013, 08:28 AM
tailchaser

Is your plastic under tray intact? NA/NB Miatas tend to not fare well in high temps at high speed without the tray, as it disrupts airflow through the radiator.
08-07-2013, 08:33 AM
orbit1

Quote:

Originally Posted by tailchaser

Is your plastic under tray intact? NA/NB Miatas tend to not fare well in high temps at high speed without the tray, as it disrupts airflow through the radiator.

That was the first thing I checked but there's nothing blocking the air flow to the Radiator...
08-07-2013, 08:41 AM
tailchaser

Quote:

Originally Posted by orbit1

That was the first thing I checked but there's nothing blocking the air flow to the Radiator...

No... you need to check for the presence of a plastic undertray beneath the engine compartment. If you can drop a bolt directly behind the radiator and it hits the ground, you don't have said undertray, and it is the most likely cause of your problem.
08-07-2013, 08:55 AM
orbit1

Quote:

Originally Posted by tailchaser

No... you need to check for the presence of a plastic undertray beneath the engine compartment. If you can drop a bolt directly behind the radiator and it hits the ground, you don't have said undertray, and it is the most likely cause of your problem.

The plastic undertray is missing, I will buy it today I just hate the fact that the temp is not normal...
08-07-2013, 08:55 AM
POS Racing

Quote:

Originally Posted by OZMDD

We need to discuss proper use of the dancing banana, this post wasn't even a single banana, much less a double. When posting, ask yourself: "if I were a fruit, how funny would this post seem?"

FYI, :confused: would be the correct emoticon for your dilemma. Good day, sir.

Well said OZMDD! Only you can prevent Banana abuse.......

So how old is the Radiator? When was the last time it was serviced?

I know many in the miata world feel the OEM Radiator should last the life of the car but sadly they don't..... ::sad banana ::
08-07-2013, 09:08 AM
orbit1

Quote:

Originally Posted by POS Racing

Well said OZMDD! Only you can prevent Banana abuse.......

So how old is the Radiator? When was the last time it was serviced?

I know many in the miata world feel the OEM Radiator should last the life of the car but sadly they don't..... ::sad banana ::

I'm sorry if I abuse the usage of the dancing banana...

I'm not too sure when it was the last time it was serviced and also I'm not too sure if it's the OEM radiator but I will check on it.. Most likely it's the original radiator from 1995..

Thanks for your suggestion and again I apologize for the dancing bananas..
08-07-2013, 09:10 AM
hornetball

Quote:

Originally Posted by orbit1

The plastic undertray is missing, I will buy it today I just hate the fact that the temp is not normal...

The undertray is a favorite victim of hack mechanics (especially oil change places) everywhere. Critical part for radiator airflow.

A brand new one at the Mazda dealer runs about $60. Worth every penny.

2 O'Clock on the OEM water temp gauge is HOT!
08-07-2013, 09:37 AM
orbit1

Quote:

Originally Posted by hornetball

The undertray is a favorite victim of hack mechanics (especially oil change places) everywhere. Critical part for radiator airflow.

A brand new one at the Mazda dealer runs about $60. Worth every penny.

2 O'Clock on the OEM water temp gauge is HOT!

Oh wow I didn't know how important is to have a undertray...

Thanks for the help...
08-07-2013, 09:40 AM
sammm

Quote:

Originally Posted by orbit1

I'm not too sure if it's the OEM radiator but I will check on it.. Most likely it's the original radiator from 1995..

OEM radiators are plastic. They are black when new, and then fade to tan/brown as they age. The lighter it is, the older/crunchier it is.
08-07-2013, 09:42 AM
orbit1

Quote:

Originally Posted by sammm

OEM radiators are plastic. They are black when new, and then fade to tan/brown as they age. The lighter it is, the older/crunchier it is.

Hmmm the plastic on the radiator is black and the radiator looks new too..
08-07-2013, 10:14 AM
POS Racing

Quote:

Originally Posted by orbit1

Hmmm the plastic on the radiator is black and the radiator looks new too..

What does it look like on the inside?
08-07-2013, 10:26 AM
orbit1

Quote:

Originally Posted by POS Racing

What does it look like on the inside?

The aluminum fins looks new, the coolant fluid is green and the underside of cap looks clean.. There's no rust or any of the dark brown stuff.
08-07-2013, 10:33 AM
Rogue

Pressure test the cooling system.
08-07-2013, 10:55 AM
jrj512

Quote:

Originally Posted by Rogue

Pressure test the cooling system.

Indeed. It will expose a lot.
08-07-2013, 11:33 AM
orbit1

Quote:

Originally Posted by Rogue

Pressure test the cooling system.

I will do that too... Thanks..
08-07-2013, 11:33 AM
orbit1

Quote:

Originally Posted by jrj512

Indeed. It will expose a lot.

OUCH!... I really don't need that...
08-07-2013, 11:42 AM
hornetball

You've got a clearly identified deficiency. Your undertray is missing. Don't waste time/money on anything else until that's remedied.
08-07-2013, 11:48 AM
POS Racing

Keep in mind if something in the cooling system fails and dumps all the coolant while your going 65 to 75 mph your chances are really good that you will be replacing expensive bits and pieces of your motor shortly thereafter.
08-07-2013, 12:39 PM
black roadster

Quote:

Originally Posted by hornetball

You've got a clearly identified deficiency. Your undertray is missing. Don't waste time/money on anything else until that's remedied.

This...
08-07-2013, 12:45 PM
orbit1

Thanks guys for all your help... I will definitely get the undertray...
08-07-2013, 02:53 PM
altiain

First thing, replace the undertray.

Second step, replace the thermostat. They are cheap, readily available, easy to replace, and known to fail.

Thirs, if that doesn't solve the problem, pressure test the system.
08-07-2013, 03:41 PM
orbit1

Quote:

Originally Posted by altiain

First thing, replace the undertray.

Second step, replace the thermostat. They are cheap, readily available, easy to replace, and known to fail.

Thirs, if that doesn't solve the problem, pressure test the system.

Thanks altiain I will keep that in mind....
08-07-2013, 07:58 PM
TexasStig

Glad you're listening and on the correct path. All's well that ends well as long as those dancing bananas stay off my lawn.

All times are GMT -6. The time now is 05:23 PM.