hi,
i own 04 that runs fine beside this issue:
when i run it for 5 km or more at 7000 rpm or more the cooling lamp is on.
i need to reduce speed and rpms to 3000 until it gone.
please help me with your ideas how to get over it.
thx yossef

 

Coolant level?
Air trapped in system?
Air flow to radiator blocked?

 

thanks for the quick replay.
there isn't pro srevice in israel !
can you be more detailed in your answer, so i can pass it on?
yossef

 

Like the BrewMan says, it is probably your coolant level, top it up.

S

 

the level of cooling water is normal and i don't have any links from any where!

 

I'm not sure what sensor is being triggered to cause the light.
It sounds like the engine is overheating so the possibilities are
not enough air reaches the radiator; Simply check for debris blocking the air flow to the rad.
not enough coolant is available; simply check the level visually.
not enough pressure? Cap defective
Air in system? Get the air bled out.

That's all I can think of

 

thanks for the info,
i will check these over and let you know the results
thanks anyways

 

Top it up, it is low.

It comes on at a very high level in the jug.

S

 

i will, thanks

 

Mine does the same thing.

I belive that at that RPM the water pump will be starting to cavitate and not pumping water as efficiently as it should be. When you are running at that high of an rpm for 5KM your engine will not be getting enough coolant to cool it down. If you want to run like that I would suggest getting a underdrive pully.

 

you suggest that i need to check the water pump!
5K for high rpms, it should accpet that, don't you think?
can you inform me with underdrive pully?
t

 

There's no need to check the water pump. It's not malfunctioning. The pump is just spinning to fast at that RPM. Mazda engineered it that way so it's pumping more water than needed pretty much everywhere else. Mazda didn't engineer the motor to be run at 8K RPM's indefinetly. If you were racing, odds are that you would be shifting and dropping the RPM's to 6K RPM's or so every once in a while.

The only way to fix the stock pump is to use an underdrive pully or pully set.

Agency Power Pulley
Unorthodox Racing Pulley Set

These will slow down the water pump (as well as the other accessories) so they aren't spinning as fast when you're pushing 8K RPM's.

 

Are you using straight water or a mix of coolant and water? If you're using just water, that may be your problem. A mix of coolant and water has a higher boiling point than just plain water.

One bit of advice, do not overheat the engine or you may be replacing the engine. These engines definitely do not like to be overheated, and it doesn't take many such incidents to destroy an engine. So, whatever the problem, get it fixed before you stress the engine anymore.

 

Have no fear, the proper water pump is almost here!

And available in Israel too.

 

Doh! I bought a UD pulley just to help with water pump cavatation! This will be yet another blow to the checkbook.

 

yes, i use mix coolnet and NOT stright water.
so i don't think it is the problem,

but my question is is it normal to get hit in such a way of driving the car, or it is not?

t

 

No, this is not normal in my opinion. Assuming you have already ruled out blockage of the radiator fins and oil-cooler fins, it is possible that you have air in the system, which needs to be bled. I know I've seen the procedure on here somewhere. Something about putting the front wheels on stands and inverting a plastic soda bottle full of coolant over the radiator fill neck, and revving the engine.... try searching...

Since it's an 04, it might be a good idea to start with a flush of the cooling system, (there is a bolt in the engine block which allows a more complete drain than just the radiator - do a search). After flush, fill with fresh 50/50 mixture and perform the bleeding procedure for good measure.

edit - the workshop manual doesn't mention the "soda bottle" technique, but here are their recommended procedures for re-filling the system (which appear to be designed to bleed the system).

After refilling....

4 Add engine coolant into the coolant resevoir tank up to the F mark

5 Install the cooling system cap

6 star the engine and warm it up by idling

7 After the engine warms up, perform the folowing steps
---1 Run the engine at approx. 2500 rpm for 5 min.
---2 run the engine at approx 3000 rpm for 5 min, then return to idling. Repeat this procedure several times.

8 Stop the engine, wait until it is cool, and check the engine coolant level. If the engine coolant level decreases, repeat steps 4 - 8.
9 Inspect each area for engine coolant leakage.

 

Almost the single worst piece of advice I have ever seen on this forum.

Never, under any circumstances use an underdrive pulley on the water pump.

The cavitation issue is not going to be solved by this and you are just reducing the efficiency of the cooling system.

Back on topic:

I also have a persistent coolant level light. I've had it on all three engines and we are certain the system is purged of air and the level is correct.
The problem is in the sensor itself.
There is a float at the bottom of the reservoir that is attached to a switch. It is supposed to measure the level of coolant in the bottle.
Unfortunately, it is, for whatever reason, affected by pressure as well.
If you have more than ~.9 bar of pressure (relative) in the bottle, it can trip the light.
This can occur if you have an over-pressure cap (like I do - its 1.1 bar) or a cap that doesn't open at the rated pressure or the sensor is just loopy.
In my case, its actually the switch because if I pressurize the bottle with a pump to just over .8 bar (relative), the light comes on.

The sensor is integrated into the tank, so you would have to replace the whole assembly, which is just as well since it has to come out to even access the sensor.
The part number is N3H1-15-350G. As you can tell by the "G", there have been a host of revisions since '03 on the thing.

 

hundreds of us are using the AP underdrive pulley with no problems ........

 

Outdated information MM !!!!!

is already up to revision H, so it should be N3H1-15-350H



Damn, I wonder what version I have. the coolant light only came on like once and that was like almost 2 years ago. even it comes on I know my system is ok, no air, and I have over 2 gallons of coolant in ....

 

If you're doing track time, turning 7 to 10k rpm constantly I would still strongly recommend use of a 'superior' water pump; one that won't cavitate at all in this range and doesn't need to be underdriven (Compromising efficiency at lower rpms).

Paul.

 

care to elaborate more on the superiority of this water pump u mentioned? what diff is it with the oem?

 

7000 rpm for 5KM or more should heat up pretty good. Even if the coolant level is fine. The stock water pump is pure and simple CRAP! It cavitates and the tolerances internally suck. An underdrive pulley may help the cavitation rpm rise but with such a lousy pump it will affect low rpm operation. As Paul says, get a better pump. They'll have one available shortly and it is something that everyone should do.

 

I've been waiting for that to come ...

I hope it will not cost me an arm and leg ......

 

That's funny. Man you've been jumping all over everyone the last few weeks.

I didn't say that out of ignorant ramblings on some Internet forum, I said that because I've observed it on my own vehicle. You may feel like it is out of ignorant ramblings, but you've made your feelings on under drive pulleys in general known.

I've had that same problem..exactly. I installed the under drive pulley. I've observed that I no longer have that problem. Have I created other problems? I have none as of yet. Will they come up? Maybe.

I don't sit at idle for extended periods so I don't really care if the water pumps under driven state means that it can't keep up at idle. I'm generally cruising at a higher RPM than I should be, but that's for another time. Can the alternator keep up? Sure it can, because I don't sit at idle and I don't have a big booming system.

I decided to try using a pulley for other reasons (mainly just wanted to see for myself what all the fuss was about) and I found out that I don't have this problem anymore. Whether it be from less cavitation, less pressure in the bottle, or whatever. (Edited to not sound so much like a d**k head....sorry everyone)

I don't know from observation that at 8k RPM the pump is cavitating, but many people on this forum with much more knowledge on this subjet than me have stated as much. Now if that's wrong, I apologize for disseminating bad information.

But, if the pump is cavitating at 8k RPM, then it is reasonable to think that if the pump is spinning less, it will cavitate less, there by increasing the cooling capacity of the system at high RPM's. Will it have side effects? Sure it will. Everything is give and take.

He may have a different problem then I did, but this did, without a doubt, work for me.

As is always the case (and as I should have stated before)....your results may vary.

Scott