Coolant sensor goes off at random times?

[Max777]

Well, I just did a coolant system overhaul because my car was overheating: I put in new hoses, new thermostat, new thermostat gasket, new hose clamps, flushed the rad with distilled, and took the AC condenser out that was blocking airflow to the rad. (Also, I drained the block, and the rad. coolant came out pretty dark, but maybe it's just the Presone Radiator cleaner I put in there?

Right now, when I start my car with the water level all the way filled, and the cap off, coolant DOES NOT burst out of the rad with "excessive force"
I had a thermostat gasket leak before, and the car would not "siphon" the coolant back out of the reservouir, but now that I put a new gasket in, it does it just fine!

Ok, so I start it, warm it up, and drive it around a bit. after about 10min or so, my coolant buzzer goes off, and sometimes STAYS on, while other times, it shuts off, and later comes back on. It's really intermittent, but the car has done it both times I drove it after I redid the coolant system.

Now, notice, the original owner said that the coolant buzzer went off on him too, and he couldnt figure it out. So, he took some wire and just grounded it to the - post on the battery. I hooked it back up, and now it does this.

I'm kinda confused, and think that my engine blew a coolant seal.

Also, there is a "gasoline" kinda smell in my oil. I just changed it about a week ago, and havent really been driving the car too often, but I let it warm up every time, and drive well, too.

EDIT: And I did "let engine idle with rad cap off and heater system set to high to bleed it"

[Phoenix7]

Is your coolant sensor plugged in too? You know, the one that sends the signal to the BUZZER?

[Max777]

yes, that's plugged in. IT was getto rigged, as I said, and I plugged it back in.

[Phoenix7]

well, you reinstalled it but are you sure it's working properly??

have you pressure checked your coolant system?

Our car used to do that and it turned out to be the t-stat was cracked and only leaked under pressure.

[Max777]

Yeah, my neck is pretty nasty.... so you replaced the neck, and it stopped doing this?

I DO have a tiny crack in my neck, and about to replace it actually, but there is not a lot of coolant that I can see coming out of there... like, no puddles, or wet spots, or anything like that. I checked. Do you really think that this could be my problem? I highly doubt it atm.

I read about hitting your coolant sensor with a hammer, and was wondering about how to do that? Is there a possibilty that perhaps there is a loose connection somewhere in the harness?

But then, wouldnt the coolant buzzer go off even when the wire to it is grounded off?

Oh, and I think there is a LITTLE bit of oil in my coolant as well.

[j9fd3s]

a pinhole leak can cause an intermittant add coolant buzzer, particularly on the freeway

[Phoenix7]

yes, It's never buzzed at me since. When the car is cold and not under pressure then you won't find the leak that's causing the buzzer to go off. Do a pressure test and see if you can find the leak.



TUrns out that the hot coolant would evaporate when under pressure and at operating temps so I never say a puddle or leak. When I tested my system I was peed on by the T-stat neck so that's how I found the crack.

[Boostmaniac]

Hmm, mine does the same thing, and I slowly lose coolant also. But I also smell a tinge of coolant near the turbo so I think I might have a small leak down there also. I just always top off the system once a week to play it safe.

Good catch on that Phoenix.

[Phoenix7]

we learn from the mistakes and experiences of others.

[Max777]

Well, I was about to have money to do my brakes (f+r pads, new rear rotors, and a new Master Cyl) as well as a new neck.... but I am about to go pick up a newer engine with only 100K on it, and a new clutch for $200, so my monies are a bit dry, and it looks like the car will have to sit for a little bit. untill I can save up enough for brakes, and to get a new neck. If the neck does not fix the problem, I will park it again, and just pull the old block out.

Here's the thread about it, do you guys see anything I dont? (except the fram?)

http://forum.teamfc3s.org/showthread.php?t=59520

[Phoenix7]

well, get the MAzdatrix replacement. 15 bux more than the stock OEM from Mazda. Had it not been for them having it in stock when I needed it I would have gone with the Mazdatrix version. Just make sure you have the NEW one ready when th eold one breaks again. 100K miles is a lot of miles.

[Max777]

Ok, so I checked it today, the coolant is always lost, but it's not a TON of it, the rad always fills up pretty quick, and also the coolant is LOST pretty quick... like, 15 min of driving the thing goes off. At home for lunch, the upper hose was still cold, but then it got hot like it's supposed to. I noticed that my coolant reservouir has dark coolant in it, and there's like an oil looking thing on the surface. Also, system seemed to have quite a bit of pressure in it, so is it possible that the iron cracked or something, and it OVER pressurizing the system? My overflow bottle DID have a bit of extra coolant before the T stat opened, so...

Also, I'm going to go order the neck from Mazda, but is there any other place cheaper, that can get it to me ASAP? Advanced didnt seem to be able to order the part.

[classicauto]

I think mazdatrix has an aluminum one for the S5.

S4 has an aluminum one stock but its got arad cap cast into it, the m-trix one is just like the s5 only aluminum and cap-less.

[WE3RX7]

S4 necks and S5 necks are not interchangeable either. Its not just the rad cap that makes them different...

[Phoenix7]

the bolt pattern is different. 2 bolts vs. 3 bolts IIRC