different temp gauge sender for relocated sensor

I moved the temp gauge sender down to the block drain plug when I did my engine swap, and now the temps are showing about 40 degrees higher. This makes sense because the sensor is right next to the crank, where the coolant is going to be the hottest. Anyways, I need a different sender, probably one with higher resistance. Anybody else run into this and found a fix?

I guess I need to call Summit or somebody that sells guages.

ehall said:

I moved the temp gauge sender down to the block drain plug when I did my engine swap, and now the temps are showing about 40 degrees higher. This makes sense because the sensor is right next to the crank, where the coolant is going to be the hottest. Anyways, I need a different sender, probably one with higher resistance. Anybody else run into this and found a fix?

I guess I need to call Summit or somebody that sells guages.

Click to expand...

I would think the hottest coolant is at the head or at the thermostat housing, just before into goes to the radiator. That's why they are located from the factory where they are.

The engine hot spots are around the cylinder walls (the combustion chamber) and the exhaust ports on the head. The current sender location is right in between two of the cylinders so it's going to be really hot down there.

I don't have much to contribute to this discussion other than the fact that the Renix ECU gets the feed for that circuit from a coolant temperature sensor that lives in one of those block drain plugs. On the HO they moved it (essentially the same sensor AFAIK) up to the thermostat housing. I guess what I'm saying is that if Jeep used each of the holes for the same purpose, could there really be that much difference in temperature? It seems like both sensors did the same function...unless maybe the Renix and OBD-I ECUs just liked a different reading. I'm not sure...good luck figuring it out though Eric, that's a mind boggler.

It also might be a case of a lack of good circulation at the drain plug for the water jacket. They put the drain at the lowest corner of the jacket, if you were to imagine the flow through a box, the corners would likely be the worst for circulation and flow. i.e. cool fluid flowing in isn't mixing into those corners and they stay hot.

I've also heard that the Head takes the brunt of the heat and will the indicator of the hottest part of the motor.

I went to my electrical mechanic about something else and while there we plugged up his scanner to look at the temperature from the ECM sensor on the tstat housing. It was showing 203, while the gauge was showing around 225. So yeah it is about 20 degrees off.

He said that we could hook up a resistor and potentiometer to adjust the guage reading, then map the resistance to his catalog and find a sender that would work. I'm glad he offered, cause I sure wouldn't want to do all that.

I did email Standard last night to ask if they knew of a sender that would work for this, but they haven't responded yet.

I am looking for a solution to relocating the sensor. Did you ever hear back from them??

The problem was the sender I was using was not good. I bought another Standard and it was also off. I pulled some from the junkyard and they were all over the place. Finally bought the cheapest part at Autozone to test and it was dead on.