temp sending unit

[diveplane]

i noticed on my 1994 v6 vortec, 2 sensors in the driver's side engine block,

what one is the temp sending unit to dashboard temp gauge, and what is the other one for? to the computer?

i need to possibly replace the sensor its giving me a false reading in cab.

will be flushing out coolant and buying new radiator hoses i have a new thermostat also to add, may as well replace these sensors.

[diveplane]

anyone have the part number at autozone for this or ebay..

thx guys.

[oldtrucksoul]

Mine's an 88. But, changed mine a few days ago and RA helped a lot.

https://www.rockauto.com/en/catalog/...+/+sensor,4748

[ChevyTech]

If I remember correctly the vortec V6 engine had a knock sensor in each head.

[diveplane]

Originally Posted by oldtrucksoul

Mine's an 88. But, changed mine a few days ago and RA helped a lot.

https://www.rockauto.com/en/catalog/...+/+sensor,4748

is the sensor threads coated in a leak proof coating , so u dont need to add

any tape?

[diveplane]

Originally Posted by ChevyTech

If I remember correctly the vortec V6 engine had a knock sensor in each head.

ah ok so 3 knock sensors on my 94 then one on the cat and 2 on each head?.

i will take a pic to show u guys what they are.

[diveplane]

ok heres pics guys


passenger side has no sensors on it only 3 plugs.

[diveplane]

manual it only shows me a v8 motor version not helping

[diveplane]

wiring diagram think i found what they are


green wire is indeed the coolant sending sensor

but i think the one above is oil pressure sender? to dash..

not a knock sensor only one on my truck that's located at the cat.

later models were outfitted with up to 4 knock units i think.

[diveplane]

Originally Posted by oldtrucksoul

Mine's an 88. But, changed mine a few days ago and RA helped a lot.

https://www.rockauto.com/en/catalog/...+/+sensor,4748

think those are for manifold to computer sensors

one am looking for goes to dashboard reading in cab.

[diveplane]

so am looking for part number for this and a place to buy guys..

[diveplane]

is this the confirmed part here guys?

http://www.oreillyauto.com/site/c/de...1392&ppt=C0039

[diveplane]

dont see any thread leak lock on that part?

[ChevyTech]

The smaller sensor in your photos is a coolant temp sensor. Do NOT use any Teflon tape on it.

The larger sensor in your photos is a knock sensor. If the computer is not setting a trouble code then you should leave it alone. They often sell people the wrong knock sensor. The sensor is more fragile then it looks and people damage the new sensor when they install it.

[diveplane]

can u give me the parts to buy direct fit.

link?

[diveplane]

but in the wiring diagram it says oil sending pressure unit to dash,

it's really a tan wire not black like in photo i uploaded..

only one knock sensor on my truck 94 that's at the cat.

if your saying thats a knock sensor then where is the oil sending pressure to dash?

[ChevyTech]

The oil sending unit is by the distributor screwed into a brass elbow.

There is no knock sensor at a catalytic converter. You are most likely looking at the oxygen sensor.

I don't know where that wiring schematic is from but it does not look like it is from GM. Even GM schematics have errors. A schematic does not give location information and just because the two sensors are next to each other in a schematic does not mean they are next to each other on the vehicle.

[diveplane]

can u give us a link to the part i need to replace temp sending
as its faulty my truck needs replaced.

[Chevyaz]

The orielly part you posted is the correct one.

[diveplane]

Originally Posted by Chevyaz

The orielly part you posted is the correct one.

so this will work for the dash gauge then? temp reading in cab.

[diveplane]

can someone respond here ok i pulled the plug out that temp switch green wire,
and it never did anything in dash the temp gauge still makes a reading wtf is going on here?

when i turn the ignition of i think i get the correct reading as it pegs up half way mark almost, turn ignition on the needle drops down the rises a little.

i replaced my thermostat gasket upper and lower radiator hoses

i need to buy that temp sensor see if it cures.

[ChevyTech]

Dash Temp gauge testing:
Unplug the sensor and the gauge should go all the way to the COLD end of the gauge.
Grounding the wire to the sensor should make it go to the HOT end of the gauge.

[diveplane]

wow fixed it thx very much chevytech and other guys, new sensor in.