- Thread starter
- #861
Only a minor update tonight, but that's about all I can muster until spring rolls around.
A couple weeks ago, I was driving my truck and realized that the engine temperature gauge would plummet instantly in cold weather while moving, then return to "normal" after an extended idle (ie: a long stop light). Thinking this behavior was strange, I decided to investigate. I discovered that my temperature gauge had been lying to me for 3 years. My wonderful PO had installed a GM sending unit into an air passageway at the back of my intake manifold, behind the carb.
So for 3 years my temperature gauge had been getting air temperature measurements from an incompatible sender...which ironically had been reading virtually "normal" in most conditions.
I had to place an order from Advance Adapters for my upcoming engine re-swap, so I ordered a GM 1/2in NPT to 1/8in BSPT adapter to hook up a Toyota sending unit in a water passage where it belongs. I also picked up a new IR thermometer, which I will use to confirm the new temperature readings.
After battling with a frozen pipe plug in the sender hole for 3 evenings, a coolant geyser confirmed I had indeed located a water passage. After I cleaned up the mess, I installed the adapter bushing:
Then put some ARP liquid thread sealer on the sender:
And installed:
I'm surprised the adapter bushing doesn't sit lower in the threaded hole than it does. However, I wouldn't dare push it any farther. I was putting what I would already consider too much pressure on the bushing trying to screw it in that far. It is actually seated with about as much (or more) thread engagement as the pipe plug had, and it LOOKS like it should be seated low enough to allow the sender's base to be submerged properly. I guess we will see!
All that's left is cutting the old GM sender connector, and running an wire extension out across the intake. It'll be ugly, but hopefully effective. Unfortunately, I have my my buddy's soldering iron back after last winter's major wiring project. As luck would have it, I found a Weller soldering iron sitting in a "electronics for recycling" bin at work today...so I snagged it. I plugged it in at my desk and it seems to get plenty hot. I'm sure it was tossed for a reason, but I'm not going to argue with a free soldering iron...I'm going to try and get some use out of it!
A couple weeks ago, I was driving my truck and realized that the engine temperature gauge would plummet instantly in cold weather while moving, then return to "normal" after an extended idle (ie: a long stop light). Thinking this behavior was strange, I decided to investigate. I discovered that my temperature gauge had been lying to me for 3 years. My wonderful PO had installed a GM sending unit into an air passageway at the back of my intake manifold, behind the carb.
So for 3 years my temperature gauge had been getting air temperature measurements from an incompatible sender...which ironically had been reading virtually "normal" in most conditions.
I had to place an order from Advance Adapters for my upcoming engine re-swap, so I ordered a GM 1/2in NPT to 1/8in BSPT adapter to hook up a Toyota sending unit in a water passage where it belongs. I also picked up a new IR thermometer, which I will use to confirm the new temperature readings.
After battling with a frozen pipe plug in the sender hole for 3 evenings, a coolant geyser confirmed I had indeed located a water passage. After I cleaned up the mess, I installed the adapter bushing:
Then put some ARP liquid thread sealer on the sender:
And installed:
I'm surprised the adapter bushing doesn't sit lower in the threaded hole than it does. However, I wouldn't dare push it any farther. I was putting what I would already consider too much pressure on the bushing trying to screw it in that far. It is actually seated with about as much (or more) thread engagement as the pipe plug had, and it LOOKS like it should be seated low enough to allow the sender's base to be submerged properly. I guess we will see!
All that's left is cutting the old GM sender connector, and running an wire extension out across the intake. It'll be ugly, but hopefully effective. Unfortunately, I have my my buddy's soldering iron back after last winter's major wiring project. As luck would have it, I found a Weller soldering iron sitting in a "electronics for recycling" bin at work today...so I snagged it. I plugged it in at my desk and it seems to get plenty hot. I'm sure it was tossed for a reason, but I'm not going to argue with a free soldering iron...I'm going to try and get some use out of it!
