What sensor is this?
I'm changing the intake manifold gasket on a 1997 1500 extended cab with a Vortec 5.7ltr. While disconnecting...everything... I noticed a broken sensor. The sensor's location is drivers side, above the exhaust manifold, between the #1 & #3 spark plugs. It has a single purple wire that runs to a plug near the intake. It screws directly into the block. I'm guessing it is some sort of temperature sensor but can not find any info on it. Any ideas?
A picture would help identify it. But, from what you are describing it sounds like the coolant temp sensor. At least that is where mine is located on my 5.3L
I have the same engine. I believe it is labeled as the ECM temp input/fan temp input.
I couldn't find any ECM temp but I did find a Temperature switch. This looks like it. Here's a link to the part. I just want to make sure. http://tinyurl.com/cd7zwdx
Yup thats it. It is one of three possible temp senders on this gen of truck. There is also one below the Thermostat housing and if the truck as an aux cooling fan one on the other side of the block in an identical place.
LOcation of the sensor I think your talking about which is a temp gauge sender
Location of second temp sender for ECM and such.
Location of possible aux sender for optional aux cooling fan. I personally don't have one.
Diagram of the aux sender
Cook thanks. I was pretty sure but just wanted a second opinion. The whole cooling system was, for the lack of a better word, "jacked up". Replaced the water pump, both hoses, upper sensor (it was broken & glued together), lower sensor connection was broken & the rubber boot was slid back over it (I'd guess to hide it) & the intake manifold gasket was spewing coolant, like a natural water spring, out from between the valve cover & intake. I did a compression test to ensure that the head gaskets were good. Luckily there was a secondary temp gage installed from previous owner. It used to have a plow on it from the looks of all the horrible wiring & switches. Thanks again guys!