temperature sensor - The 1947 - Present Chevrolet & GMC Truck Message Board Network

worldofme · 06-05-2002, 04:24 PM

my temperature gauge on my dash is all !@#$&* up. the needle is pointing way past hot no matter if the engine is hot or cold and it stays in that position even when the engie is off. i was talking to my dad on the phone last night and he thinks maybe the temperature sensor has possibly gone bad and to check that. question is, I don't know where to look for. he said it could be somewhere on the side of the engine block and the only thing I can find like that is on the passenger side. my book for my blazer doesn't say anything about a temperature sensor.

so if there is such a thing as a temperature sensor, where should it be located and if not what could possibly be causing my gauge to be all screwy.

this is for a 1977 chevy blazer full

kickinbigblock468 · 06-05-2002, 10:10 PM

there is such thing as a tempature sensor. on small block chevy engines their usually on the drivers side. It will be a plug in the side of the block that has a wire running out of it. im not to sure about big blocks tho. Good Luck

Dan

worldofme · 06-05-2002, 10:43 PM

the engine is a small block 350. the only thing I see that could be considered a plug of any sort is on the passenger side. it has a wire running from it and up over the backside of the engine towards the driver side. im assuming that could be it.

by the way, do you or anyone else know where I can find a good book on blazers for the year 1977? I have a Chiltons and it's ok but I'd like something that gives a bit more detail and covers more info about the engine and it's components.

thanks for the input too.

gchemist · 06-06-2002, 07:15 AM

worldofme,

The sensor in on the driverside head between the 3 and 5 cylinders. If I remember correctly the wire is green. If you want a factory manual try looking at www.ebaymotors.com. I bought a '83 factory manual for $35!! It has more details than the Shiltons will ever have.

When you replace it be sure and not to put any sealant or tape on it. It must ground directly to the block. Either the sensor is bad or the connection on the sensor is bad. Either way your problem is likely a bad ground.

455sd · 06-27-2002, 06:46 AM

From my experiance it probly is not your sender it is most likly the sender wire has earthed out or a bad earth on the rear of the gauge cluster .A electronic gauge will always read maxinum if it is earthed to body.

massel · 07-02-2002, 11:32 AM

I have had problems with the factory gauges on all of the older vehicles i have owned. In my opinion you are better off buying aftermarket gauges such as autometer for oil pressure, water temp and amps. I just put in a new water temp gauge in my 85' it was located between the front most header tube and the second one if you are in front of the engine on the driverse side and it just screws out. Be sure to drain the coolant or it will drain out the hole for the sensor.

Longhorn Man · 07-02-2002, 08:48 PM

Hi there, just passing through from the 67 - 72 board....
If the guage stays pegged while the engine and ignition is off, your guage will more likely than not, be the problem.
However, if the guage goes down while the ign is off, and it pegs when you turn it on, then you have a bad wire that goes to the temperature sending unit. Look real carefully at the wire onvce you find it. Trace it to the firewall. It'll probably be melted to an exhaust manifold, or posably dammaed somewhere else.
I also agree about the aftermarket guages. Even the lower cost ones will be more reliable then your old stock ones ever were.

06-05-2002, 04:24 PM	#1
worldofme Registered User Join Date: Sep 2001 Location: CA Posts: 15	temperature sensor my temperature gauge on my dash is all !@#$&* up. the needle is pointing way past hot no matter if the engine is hot or cold and it stays in that position even when the engie is off. i was talking to my dad on the phone last night and he thinks maybe the temperature sensor has possibly gone bad and to check that. question is, I don't know where to look for. he said it could be somewhere on the side of the engine block and the only thing I can find like that is on the passenger side. my book for my blazer doesn't say anything about a temperature sensor. so if there is such a thing as a temperature sensor, where should it be located and if not what could possibly be causing my gauge to be all screwy. this is for a 1977 chevy blazer full

06-05-2002, 10:10 PM	#2
kickinbigblock468 Registered User Join Date: Mar 2002 Location: Beacon Falls Connecticut 06403 Posts: 31	tempature sensor there is such thing as a tempature sensor. on small block chevy engines their usually on the drivers side. It will be a plug in the side of the block that has a wire running out of it. im not to sure about big blocks tho. Good Luck Dan __________________ 1981 Chevy Silverado 468 cid big block Edelbrock Tunnel Ram Dual Quad Intake (2 600cfm edelbrock) 11.5:1 compression Comp roller cam and lifters Comp cams roller rockers Steel Manley connecting rods MSD-10 ignition with Pro Billet distributor Pete Jackson gear drive timing gears Saveing for a set of Alluminum heads and an 8-71 Blower

06-06-2002, 07:15 AM	#4
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	worldofme, The sensor in on the driverside head between the 3 and 5 cylinders. If I remember correctly the wire is green. If you want a factory manual try looking at www.ebaymotors.com. I bought a '83 factory manual for $35!! It has more details than the Shiltons will ever have. When you replace it be sure and not to put any sealant or tape on it. It must ground directly to the block. Either the sensor is bad or the connection on the sensor is bad. Either way your problem is likely a bad ground. __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

06-27-2002, 06:46 AM	#5
455sd Registered User Join Date: Jun 2002 Posts: 2	*#$%^& temp sender** From my experiance it probly is not your sender it is most likly the sender wire has earthed out or a bad earth on the rear of the gauge cluster .A electronic gauge will always read maxinum if it is earthed to body.

07-02-2002, 11:32 AM	#6
massel Registered User Join Date: Jun 2002 Location: holland, mi Posts: 19	I have had problems with the factory gauges on all of the older vehicles i have owned. In my opinion you are better off buying aftermarket gauges such as autometer for oil pressure, water temp and amps. I just put in a new water temp gauge in my 85' it was located between the front most header tube and the second one if you are in front of the engine on the driverse side and it just screws out. Be sure to drain the coolant or it will drain out the hole for the sensor. __________________ Anyone can buy a truck, It takes someone special to build one! 85' prostreet silverado 350/330 horse crate motor 700r4 tranny, 4:88's in the rear

06-05-2002, 10:43 PM	#3
worldofme Registered User Join Date: Sep 2001 Location: CA Posts: 15	the engine is a small block 350. the only thing I see that could be considered a plug of any sort is on the passenger side. it has a wire running from it and up over the backside of the engine towards the driver side. im assuming that could be it. by the way, do you or anyone else know where I can find a good book on blazers for the year 1977? I have a Chiltons and it's ok but I'd like something that gives a bit more detail and covers more info about the engine and it's components. thanks for the input too.

07-02-2002, 08:48 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Hi there, just passing through from the 67 - 72 board.... If the guage stays pegged while the engine and ignition is off, your guage will more likely than not, be the problem. However, if the guage goes down while the ign is off, and it pegs when you turn it on, then you have a bad wire that goes to the temperature sending unit. Look real carefully at the wire onvce you find it. Trace it to the firewall. It'll probably be melted to an exhaust manifold, or posably dammaed somewhere else. I also agree about the aftermarket guages. Even the lower cost ones will be more reliable then your old stock ones ever were.



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