Moving the temp sensor

[Mattsfmj]

Hey all my 1984 k10 has the coolent temp sensor down by number one spark plug (green wire). Has anyone everyone moved the sensor up to the intake by the thermostat housing and rerouted the wire to get it away from the exhaust. I guess my question is does it give accurate readings. Or does anyone know a better place to put the sender? Thanks

[Captkaos]

If you want it to be accurate, leave it where it is.

[LTZ C20]

That current location is the factory location and the most accurate. If you are worried about it getting burnt by the exhaust, here's something you can do.

You can re-route it. Obtain some bulk wire that is the same size as the factory wire, also get some plastic wire loom of appropriate size and the matching size heat shrink butt connectors. You shouldn't need more that about 3 feet or so of each but most bulk wire comes in longer bulk length tho. Then cut the wire about 2-3 inches out from the bulk head connector, then cut the end that connects to the temp sensor itself about 1-2 inches from the back end of the terminal. This should give you a short "stub" wire at the bulk head connector and a temp sensor connector with a short "tail".

Then take the new wire, crimp on a butt connector and connect it to the "stub" at the bulk head, then run it with the harness towards the distributor, once you get there, make a left and run it towards the front of the engine between the valve cover and intake, once you get parallel with the temp sensor, make a left and got up and over the valve cover and then straight down to the temp sensor. Cut the wire off the spool, crimp on the connector "pig tail", heat shrink anything that needs to be, put the plastic wire loom over the wire from the bulk head to the temp sensor and connect the sensor.

In short, all your doing is cutting out the old wire and adding new, longer wire. The new wire won't be deteriorated from years of use. Putting it between the valve cover and intake will still be hot, just not serious heat from the exhuast. The plastic loom just adds a little protection and looks cleaner.

Hope that gives you an idea, and the above process applies to V8's. Assuming you have a 350.

[enaberif]

Its been a long time argument over where the best spot for a temp sensor is... Some say the head.. some say near the thermostat.

They say near the head can read higher than normal due to it being near the exhaust and such. Others say near the thermostat gives a better reading because its a straight shot from the radiator.

Either way moving the sensor will require coolant to be drained.

[LTZ C20]

This is true, however, even brand new trucks come with them in the head.

[Irish_Alley]

me and my buddy where just talking about where to put a pyro gauge on the cummins. most put it after the turbo. but the hottest part is the manifold, who cares what the temp is after the turbo cause it probably cooled down by then i want the hottest reading that way i know what is my highest temp. i would think the head would give you the hottest temp

[enaberif]

me and my buddy where just talking about where to put a pyro gauge on the cummins. most put it after the turbo. but the hottest part is the manifold, who cares what the temp is after the turbo cause it probably cooled down by then i want the hottest reading that way i know what is my highest temp. i would think the head would give you the hottest temp

The head has the most  heat yes but its also the most "fake heat" because you have heat from the engine, heat from the coolant, and heat from the exhaust.

[Captkaos]

It is inside the head in the coolant passage closest to the hottest portion of the motor (the combustion chamber).  Outside heat isn't going to impact it in any way.  You don't want to measure the median heat, you want the hottest.

[LTZ C20]

What Capt said.

[Stewart G Griffin]

Read this:
http://www.madelectrical.com/workshop/water-temp-gauge2.shtml

http://www.madelectrical.com/workshop/water-temp-gauge.shtml


i've got the WARNING LIGHT sensor in the head and the TEMP GAUGE sensor in the intake near the thermostat.  Works for me.

[Irish_Alley]

stew didnt you just change your motor because of a overheating problem?

[blazer74]

I moved my sender to the intake next to the thermostat when I did a vortec head swap on my 74.

I used the factory sender for my factory gauge which fit in the vortec intake but the head uses a smaller size and did not want to use an adapter.

I researched and did not find a smaller sender
That had the same resistance.

The only difference I noticed was the temp goes to a hotter reading on initial warm up until the thermostat opens and water starts flowing and the temp comes down and reads normal from then on.

[Stewart G Griffin]

stew didnt you just change your motor because of a overheating problem?

Point taken, however i think the majority of the damage was done over last summer, when the gauge went high AND the warning light came on.   i was able to get them to go down as soon as i was able to break free from traffic.  It was downhill since then.  The last time i drove it, and i may have gone a little hot, i don't think would have made much a difference in terms of total engine damage---most of it was last summer AND the fact that the engine was never rebuilt in 36 years.

[VileZambonie]

The source of heat in your heat engine is the combustion chamber. The temperature of operation is surrounding the combustion chamber area. Operating temperature is going to be most accurately read and give first indication of trouble right in the factory location. The coolant sensor located near the thermostat is not located there to warn the driver, rather to provide input data to the ECM for fuel trim. Leave the coolant temp sender in the cylinder head so that it can provide its intended function.