coolant temp sensor

HKstang · 04-13-2001, 06:43 PM

If my coolant temp sensor was bad, would my car be running rich due to the computer thinking the car is still cold? And also, is this the sensor my stock water temp guage reads off? I'm asking because I just bought another Mustang and the temp sensor isn't reading and my friends saw a puff of black smoke when I got on it.

Thanks
Geoff
90 LX notch

Capri306 · 04-13-2001, 09:55 PM

Yes and no, in that order.

If I read your post correctly, you say your temperature gauge doesn't read anything? So the car's not even warming up at all? Yeah, that could cause some problems for sure, just like what you're talking about. Make sure the radiator & its reservoir are full and that the cap is tested & operating properly. If the engine still won't warm up you need to replace your stuck-open thermostat. I'm willing to bet this is your problem in a nutshell.

Has your check engine light come on??? It should have, since it's probably not going into closed loop. Change your plugs & run some good fuel system cleaner (recommendation: VP Racing Fuels). Good luck.

------------------
Capri306, Moderator, The Mustang Works Online
1979 Mercury Capri, 5.0L -- C4 -- 2.73
1987 Mustang LX Notch

[This message has been edited by Capri306 (edited 04-13-2001).]

HKstang · 04-13-2001, 10:23 PM

I think my car is warming up but the computer just doesn't know it. I'm getting heat from the vents so it's got to be getting warm right? Right?

Geoff

withamc · 04-14-2001, 01:34 AM

The coolant temp sender your guage uses is on the front driver's side of the intake manifold near the distributor. It is not the same sender your computer uses which is in the heater line near the front.
To see if your guage works, pull the plug off the temp sensor and put a 42 or 47 ohm resistor between the plug and ground. Turn on the key and you should see the guage register somewhere below 1/2 scale. If that works, your sender is probably bad. Put an ohm-meter between the sender and ground with the engine warm, it should read somewhere between 40 and 50 ohms. Also if you've got a bad ground between the block and the chassis your guages will read wacky.

[This message has been edited by withamc (edited 04-15-2001).]

04-13-2001, 06:43 PM	#1
HKstang Registered Member Join Date: Feb 2001 Location: Toronto Canada Posts: 44	coolant temp sensor If my coolant temp sensor was bad, would my car be running rich due to the computer thinking the car is still cold? And also, is this the sensor my stock water temp guage reads off? I'm asking because I just bought another Mustang and the temp sensor isn't reading and my friends saw a puff of black smoke when I got on it. Thanks Geoff 90 LX notch

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04-13-2001, 09:55 PM	#2
Capri306 Moderator Join Date: Sep 1998 Location: Grand Rapids, Michigan, USA Posts: 1,001	Yes and no, in that order. If I read your post correctly, you say your temperature gauge doesn't read anything? So the car's not even warming up at all? Yeah, that could cause some problems for sure, just like what you're talking about. Make sure the radiator & its reservoir are full and that the cap is tested & operating properly. If the engine still won't warm up you need to replace your stuck-open thermostat. I'm willing to bet this is your problem in a nutshell. Has your check engine light come on??? It should have, since it's probably not going into closed loop. Change your plugs & run some good fuel system cleaner (recommendation: VP Racing Fuels). Good luck. ------------------ Capri306, Moderator, The Mustang Works Online 1979 Mercury Capri, 5.0L -- C4 -- 2.73 1987 Mustang LX Notch [This message has been edited by Capri306 (edited 04-13-2001).]

04-13-2001, 10:23 PM	#3
HKstang Registered Member Join Date: Feb 2001 Location: Toronto Canada Posts: 44	I think my car is warming up but the computer just doesn't know it. I'm getting heat from the vents so it's got to be getting warm right? Right? Geoff

04-14-2001, 01:34 AM	#4
withamc Registered Member Join Date: Aug 2000 Location: Thousand Oaks, CA Posts: 396	The coolant temp sender your guage uses is on the front driver's side of the intake manifold near the distributor. It is not the same sender your computer uses which is in the heater line near the front. To see if your guage works, pull the plug off the temp sensor and put a 42 or 47 ohm resistor between the plug and ground. Turn on the key and you should see the guage register somewhere below 1/2 scale. If that works, your sender is probably bad. Put an ohm-meter between the sender and ground with the engine warm, it should read somewhere between 40 and 50 ohms. Also if you've got a bad ground between the block and the chassis your guages will read wacky. [This message has been edited by withamc (edited 04-15-2001).]