MavrickFD

Came on after about an hour of driving and stopping at 3 places. When I got home and shut down, I turned the car back on without starting the engine to turn on my fans right away. After about five seconds later the buzzer sounded. I looked in the over flow tank and it still had some. I decided to wait until the engine cooled down before opening up the radiator cap. After about 45 minutes, I turned on my car again to see if the buzzer sounded again but it didn't. Did I just have air in there or what?

Force13B

iTrader: (19)

Have you done any modifications to your car lattly?

MavrickFD

No. Got it with an HKS intake, BOV, and exhaust already installed.

silverflash2

iTrader: (2)

Check for leaks now under the car,I had a leak from a rat or squiral chewing on my radiator hoses, turbo hose and hose near the back of the UIM near the tranny. Also might want to replace both caps.

Force13B

iTrader: (19)

Make sure you not leaking coolant anywhere, i would bet you got a bubble in the line that just got burped through. Or worst case, the sensor is shorting out.

MavrickFD

haven't been leaking anywhere. By next paycheck I plan on getting the radiator flushed and probably change out the caps. Any suggestions on the caps I should get for a reasonable price?

coolvette

i just ordered a t-stat cap from malloy mazda,it was around 14.00 shipped

adam c

iTrader: (2)

So, you let the car cool, and you opened the cap. What did you find? Was it low? Did you fill it? Did you fill the AST?

MavrickFD

I didn't open up the cap yet because it was still hot and I had to go to work. When I started it back up again the buzzer didn't com on. That's what confused me. I thought you weren't supposed to service it from the AST?

sonix7

Its probably the coolant level is not high enough for the sensor to read it. In the thermostat housing is where the stock sensor is and if your coolant level is not high enough your sensor will go off. Now, if your coolant is low then maybe you just needed to top it off, I believe its normal for a little coolant to burn off, but if you are losing coolant then it could be a number of things. Check the turbo coolant hoses for problems http://www.robrobinette.com/turbo_lines.htm, and the worst case scenario would be a blown coolant seal, but exhaust all other avenues before diagnosing a blown coolant seal.

vellj001

Mine does it rarely. Especially when it is very hot wheather especially in summer. It just as it has been already described. Water dries out off the sensor. It usually does is more often when I flush the coolant but that is because of air bubbles that one has to purge out by adding coolant water for a while after the coolant has been flushed.

Usually I just let her cool down and add water. I would not worry that much if it does it once in a while when it is really hot.

tsmysak1

The buzzer occurs when the coolant is low in the filler neck. Possible causes"

1) Low coolant - *chuckle*
2) Coolant leak somewhere - anywhere for that matter
3) Burning coolant
4) Not returning coolant into the system when cooled

If it is not occuring regularly, then you might expect that the worst has not happened yet. Cross your fingers.

So here is general description for you. System is full. Engine heats up. coolant is not compressable. Coolant expands under pressure and pushes past the rubber seal on the AST, through a hose that runs to the over flow tank. System cools and sucks the coolant through a second valve located in the center of the AST cap. It is the little silver center cap that pulls out and lets coolant back in.

Assuming you start with a full system, there will not be enough vaccum to suck it back completely full. There is always a little hysteresis. There will be a little bit of space left in the system, which collects at the filller neck. This is one of its main purposes in life. If you keep adding a little coolant when totally cool, the level in the overflow will go up and you will go completely freekin nuts thinking you've blown a combustion/coolant seal.

Any vaccum leak anywhere will enhance the effect of leaving more coolant in the overflow. Debris on the cap. Dirty seals, dirty hose connections, etc. etc. etc. yadda yadda yadda. Some leaks will leak out coolant onto the floor. Other leaks will just let air back into the system. Every time you dink with the coolant system, you are going to stir something up and possibly decieve yourself into thinking you've blown a seal. Heart rate goes up and you don't sleep at night.

If you smell coolant in the exhaust, this is bad. There should be signs then of combustion gas in the coolant perhaps maybe sometimes also. Sorry to be nebulous. Not all bad seals do the same thing. At any rate, this can cause low coolant to occur. The combustion gas that pushes past the internal coolant seal replaces coolant in the system pushing it out into the overflow. Then the gas also equlaizes the vaccum that would occur from the coolant volume shrinking at cooling time. Therefore it is never sucked back in the system. Coolant level goes up in the overflow tank, but in this case, it eventually requires an overhaul.

Clean your caps well and also the surface they seal against. They could have oil, grease, dirt, etc. and this will result in an overflow and lack of vaccum to pull it back. New caps are best, but you may be chasing your tail if the sealing surfaces are not clean.

Check for leaks and old hoses. Especially around the throttle body where the engine coolant is piped up to warm the wax rod near the fire wall. Check and or replace the line from the AST to the overflow tank (no small feat).

Have someone start your car cold for you and you stand out behind the exhaust to observe. There will be a mixture of condensation, gas, fumes, etc...Kind of hard to tell. A really bad coolant seal will be obvious.

Well that is all I can think of for now.

Do the simple things first.

adam c

iTrader: (2)

When cold, open both caps. Remove the throttle body coolant line (behind the throttle body). Keep an eye on it to see if coolant starts coming out when you fill the system. If coolant starts to come out, replace the line. Fill the ast, and wait to see if it goes down. Repeat until it does not go down. Cap the ast, and fill slowly at the filler neck until it will not take any more. Cap the filler neck, and TB coolant line. Drive the car, and check again after it completely cools. Repeat the process if necessary. If the low coolant warning continues, then you have a leak, or are burning coolant (bad).