The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Cannot find correct coolant temp sending unit

tucsonjwt · 07-05-2019, 07:24 PM

Yup. I got the whole "nominal" 3/8" vs. "actual OD 3/8" thing you reference.

I am being led down that actual 3/8" diameter hole in the engine path to take the part descriptions to literally mean a 3/8" diameter thread on the end of the sensor. Since I only have a 3/8" diameter hole, I was thinking that the part descriptions referred to the type of thread, not actually sticking a 3/8" iron pipe nipple in the engine, which would require I lot bigger hole.

This engine is actually a Goodwrench factory rebuilt engine, so who knows what mis-mash of pieces ended up on that engine. I still think somebody has the correct sensor somewhere, and given the different temperature response characteristics for the various sensors I would like to get the correct one.

I will say that the old existing sensor is still sending a signal - just an incorrect signal. I guess I could continue looking for an abnormal spike in the gauge relative to its typical setting (135-150 degrees?), but I am very anal about things like this. A big block in the 110 degree ambient desert climate makes me nervous about overheating this beast, so I keep a close eye on the temp gauge. Every part of the cooling system has been replaced, but it doesn't take much of a part failure to roast that engine.

07-05-2019, 07:24 PM	#9
tucsonjwt Registered User Join Date: Jul 2007 Location: Tucson, AZ Posts: 3,188	Re: Cannot find correct coolant temp sending unit Yup. I got the whole "nominal" 3/8" vs. "actual OD 3/8" thing you reference. I am being led down that actual 3/8" diameter hole in the engine path to take the part descriptions to literally mean a 3/8" diameter thread on the end of the sensor. Since I only have a 3/8" diameter hole, I was thinking that the part descriptions referred to the type of thread, not actually sticking a 3/8" iron pipe nipple in the engine, which would require I lot bigger hole. This engine is actually a Goodwrench factory rebuilt engine, so who knows what mis-mash of pieces ended up on that engine. I still think somebody has the correct sensor somewhere, and given the different temperature response characteristics for the various sensors I would like to get the correct one. I will say that the old existing sensor is still sending a signal - just an incorrect signal. I guess I could continue looking for an abnormal spike in the gauge relative to its typical setting (135-150 degrees?), but I am very anal about things like this. A big block in the 110 degree ambient desert climate makes me nervous about overheating this beast, so I keep a close eye on the temp gauge. Every part of the cooling system has been replaced, but it doesn't take much of a part failure to roast that engine.