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Why is my lil' Na6 running nice ? - Coolant sensor broken !!
Posted: Mon Aug 30, 2010 9:23 pm
by kazjim
Hey all, got a strange one for you ....
Most mornings my lilttle Na6 with Loch Stewart intake is a little 'lumpy' and usualy stalls as i get to the end of my street .... no biggie ..
But i noticed on the weekend that the coolant sensor on the thermo housing was cracked and sitting 'loose' in the nut ..
Took it out, disconnected the wire and took it for a drive ... it runs nice
so, i started it this morning (cold start in Gosford ... a bit chilly) and it didnt stall !
So, i ask you ... what has happened, and should i bother fixing it !
havnt taken it for a long drive yet, so dont know if fuelling / Fuel usage has been changed
Cheers
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Mon Aug 30, 2010 9:56 pm
by jerrah
Is it the front or the rear sensor that controls the fans?
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Mon Aug 30, 2010 10:05 pm
by kazjim
Hmmm, I"m guessing the front one ...
its small, one wire and vertical... sits above the thermo housing
so, it only controls the fans ?
No worries then
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Tue Aug 31, 2010 1:15 pm
by manga_blue
I'm not sure what the setup is on the NA6 but on the NA8 the engine coolant termp sensor (ECT) feeds a temp signal to the ecu. The ecu uses this to determine mixtures and to control the fans (among other things). If you disconnect the sensor then the ecu falls back to an assumption that the engine is a bit coolish and sets things a bit rich. Maybe if your ECT sensor had been feeding bad signals then the ecu may have been doing all sorts of things wrong and the fallback position is better, although you could now find fuel economy is awful. For my car I'd get a new sensor asap - about $90 from Mazda (ouch), unless someone knows of an aftermarket alternative that works (usually around $10-20).
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Tue Aug 31, 2010 2:12 pm
by jerrah
NA6 has two sensors. One for the fans and one for the ECU. The fan sensor controls the fans directly without ECU involvement AFAIK?
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Tue Aug 31, 2010 4:53 pm
by jerrah
miataturbo.net seems to say the front one is the fan control. Are your fans still switching on?
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Tue Aug 31, 2010 9:51 pm
by kazjim
Cant really say, been too cold here and I've only made short trips .... will know tomorrow - off to work in the city ...
Cheers all
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Wed Sep 01, 2010 12:37 am
by manga_blue
jerrah wrote:NA6 has two sensors. One for the fans and one for the ECU. The fan sensor controls the fans directly without ECU involvement AFAIK?
Yeah, my bad, just checked the NA6 service manual, Jerrah. You're right. For the NA6 this is just the fan switch. NA8 is very different.
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Wed Sep 01, 2010 5:18 pm
by mazdatenfive
I have a spare one of those sensors if you would like it, pm me.
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Wed Sep 01, 2010 9:43 pm
by kazjim
Well, funny story ....
So you know how today was a bit warmer ?
Guess who got stuck in traffic ?
It got a bit hot so hard-wired the fan switch to permanently on.....
saved the overheating i think, but I"ll be PM'ing MazdaTenFive any second now
Cheers all
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Fri Sep 03, 2010 7:15 pm
by meta
ironically, i have exactly the same problem and am after one of those thermo switches!!!
If anyone else has one pm please!
Thanks Meta
Re: Why is my lil' Na6 running nice ? - Coolant sensor broke
Posted: Sat Sep 04, 2010 8:57 pm
by kazjim
Picked up the sensor from MazdaTenFive this afternoon, will be fitted tomorrow ....
Thanks again, appreciate the help...
Free Bump for Meta !