vmb

what would the symptoms of a failed thermosensor ?
dont show me how to test it ,i already know i just want to know how the car would react with a bad one.

dre_2ooo

mght be a little rough when engine is cold.... possible bad idle.

when warm, it'll run perfectly. See, when the thermosens0r goes out, it defaults 80*C (174*F) to the ECU, hence normal operating temp.

You would get a check engine light should this happen

vmb

i got the code 9 in my car
it doesnt run weird when its cold though.

MrGoodnight

iTrader: (1)

One decade bump, at least I searched.


Some wierdd things are happening to my NA.
I've driven it 22,xxx miles and it has flooded no more than 3 times.

Drove home from work, stopped by some place and got food. Went out to my car, it flooded.
I was like okay, wierd but no issue. Deflooded it and got it started. It was idling around 2000 rpm, which is where it usually is when it's cold.

Obviously my vehicle was warm, my temp also started to creep up until I started driving then it went back down. I'm assuming that my thermo sensor is bad and thinks my car is cold so too much fuel flooded it? Thinks its cold so high idle? Thinks its cold so my clutch fan was disengaged and no airflow till I started driving?


What are the symptoms?
My fuel economy is fine (20mpg).
Runs perfect no hesitation at all.
No cold start issues at all.

Other threads I have read say poor fuel economy and runs crappy are issues with bad thermo sensors.


S4 NA, 130,xxx miles. Engine %100 stock, emmissons and everything.
Edit: No check engine light as well.

clokker

iTrader: (2)

The thermosensor has absolutely no connection to or effect on the fan.
2000 rpm is awfully high for a "normal" cold idle, mine is @ 1200rpm.

Before making assumptions, I'd wait and see if the flooding becomes a regular occurrence...sometimes **** just happens.

The bit about the temp rising till you started moving is a little worrisome though.
With a warm engine and bay the fan should be fully locked up (at least as much as it ever gets, which IIRC, is @ 80%) and you should be able to sit and idle essentially forever with a stable temp.

MrGoodnight

iTrader: (1)

That's wierd, every time I start my car in the morning it idles around 2000rpm for a couple minutes and slowly works its way down until I reach operating temp. Then it's around 800 or so.


That is true, I will see what happens in the next few days.



Yes exactly, I was unaware that the fan and thermo sensor have no connection.
Maybe my clutch fan is on its way out?
I've never had any overheating at idle problems ever before.
Before I stopped I was at red lights on my way home and my temp was fine as usual. A fluke?

I've only had my car over heat once last year, and it was the thermostat, replaced it and everything was fine.

clokker

iTrader: (2)

The idle should jump up about that high for about 15-17 seconds at full cold start, then drop to @1200 rpm till it warms up.
Maybe check your thermowax adjustment.

MrGoodnight

iTrader: (1)

Okay I'll check that out.

Thanks for the help!

clokker

iTrader: (2)

Well, a qualified "you're welcome".
You won't be thanking anybody (and probably cursing Mazda) because it can't be done with the throttle body in place.
I just went through the procedure with mine but the entire intake was already off, so it was kinda fun.
You can expedite the test process by pouring boiling water followed by ice water through the thermowax loop which will quickly extend and contract the plunger.
Makes setting the cam really fast and easy.

MrGoodnight

iTrader: (1)

Found my problem:



But that's okay, already swapped it out:

clokker

iTrader: (2)

Just for future reference, that is the hard way to check the thermowax.

87 t-66

iTrader: (133)