Temp sensors are very different
Rock Crawling
Joined: Jan 2021
Posts: 461
Likes: 75
I don’t believe this wild fluctuation should be happening. Sounds like either a bad temp sensor, air in the radiator making its way to the temp sensor, or a wiring problem with the temp sensor.
However, the temp sensor near the T-stat does not control the t-stat (to my understanding). This is the cold side t-stat that monitors the temp of the coolant coming out of the radiator before it joins the loop through the block. This t-stat should always be significantly cooler than the hot side t-stat, which is at the back of the engine measuring the temp of the coolant leaving the block.
However, the temp sensor near the T-stat does not control the t-stat (to my understanding). This is the cold side t-stat that monitors the temp of the coolant coming out of the radiator before it joins the loop through the block. This t-stat should always be significantly cooler than the hot side t-stat, which is at the back of the engine measuring the temp of the coolant leaving the block.
Is there any way to test the t-stat? Hate to go through the effort of fitting a new one and accomplishing nothing.
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Winching
Joined: Aug 2019
Posts: 602
Likes: 164
From: Charlotte, NC
The pressure should be released when the engine is cold, like sitting there for 12-16 hours cold. That is with any car so something is going on.
Only thing I can think of is unplugging the electrical connector to the thermostat housing and checking it with a multi-meter with the ohms setting. I don't know what the correct reading would be.
Only thing I can think of is unplugging the electrical connector to the thermostat housing and checking it with a multi-meter with the ohms setting. I don't know what the correct reading would be.
Rock Crawling
Joined: Jan 2021
Posts: 461
Likes: 75
The pressure should be released when the engine is cold, like sitting there for 12-16 hours cold. That is with any car so something is going on.
Only thing I can think of is unplugging the electrical connector to the thermostat housing and checking it with a multi-meter with the ohms setting. I don't know what the correct reading would be.
Only thing I can think of is unplugging the electrical connector to the thermostat housing and checking it with a multi-meter with the ohms setting. I don't know what the correct reading would be.
Also trying to understand the temp differential I'm observing between front and rear and if it means anything with regards to this or something else.
Rock Crawling
Joined: Jan 2021
Posts: 461
Likes: 75
Your thermostat may be not opening fully if temp sensor 2 it is topping out at 165.
Due to the back order, I elected to put in the thermostat housing from the V8 LR4. This has the same hose connections but has a normal style thermostat (not electric) inside to control the bi-pass and open the thermostat. The thermostat housing for the V6 supercharged 3.0 has an electronic thermostat. Per the workshop manual this is so the ECU can manipulate the bi-pass and thermostat flows without having to wait for the water to heat up to "control the flow and pressure, to protect the engine components." The bi-pass starts fully open on the V8 thermostat housing so the flow is there and the thermostat is 190 degrees when it begins to open vs. "208-2015" to begin to open and "226" fully open.
I took the old electrical connector off the old thermostat housing and made a blank out of it and wrapped it with gorilla tape and then zip tied it secure. No codes, I think it was just an electrical current with no feedback to the ECU.
I like having a lower temp thermostat. I'm coming from the D2 world where Land Rover intentionally ran the engines hotter to comply with emission standards. The negative part is hotter engines over time don't last as long. I believe the same is being done with a lot of newer engines, hotter for emission requirements at the detriment of the life of the engine. Running in in the 190's.
Due to the back order, I elected to put in the thermostat housing from the V8 LR4. This has the same hose connections but has a normal style thermostat (not electric) inside to control the bi-pass and open the thermostat. The thermostat housing for the V6 supercharged 3.0 has an electronic thermostat. Per the workshop manual this is so the ECU can manipulate the bi-pass and thermostat flows without having to wait for the water to heat up to "control the flow and pressure, to protect the engine components." The bi-pass starts fully open on the V8 thermostat housing so the flow is there and the thermostat is 190 degrees when it begins to open vs. "208-2015" to begin to open and "226" fully open.
I took the old electrical connector off the old thermostat housing and made a blank out of it and wrapped it with gorilla tape and then zip tied it secure. No codes, I think it was just an electrical current with no feedback to the ECU.
I like having a lower temp thermostat. I'm coming from the D2 world where Land Rover intentionally ran the engines hotter to comply with emission standards. The negative part is hotter engines over time don't last as long. I believe the same is being done with a lot of newer engines, hotter for emission requirements at the detriment of the life of the engine. Running in in the 190's.
Now that you've fitted a new t-stat, what is the differential between the sensors on yours?
A tech I know says there must be air trapped in the t-stat which's causing all of these issues, but no idea how to get the air out since there's no bleeder on the t-stat.
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Winching
Joined: Aug 2019
Posts: 602
Likes: 164
From: Charlotte, NC
My LR4 is a re-build so I'm just getting it going. I don't have a licence plate on it yet so I've only driven it around the neighborhood. But it is in the mid to upper 190's. Sitting at idle 203.
After everything gets up to temp especially at idle the temps match or are very close.
I don't think you have air in your thermostat, it would have been pushed out by the flow by now. I think your thermostat is just not opening all the way or the bi-pass valve is not closing so not enough flow is going through the radiator to bring up the temps of sensor #2 (just below the thermostat housing).
After everything gets up to temp especially at idle the temps match or are very close.
I don't think you have air in your thermostat, it would have been pushed out by the flow by now. I think your thermostat is just not opening all the way or the bi-pass valve is not closing so not enough flow is going through the radiator to bring up the temps of sensor #2 (just below the thermostat housing).
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Winching
Joined: Aug 2019
Posts: 602
Likes: 164
From: Charlotte, NC
Better place to test that temp is remove the small skid plat. You may have to also remove the plastic guard that is on the passer side. You will be able to feel the large hose coming to of the bottom of the radiator. If it is 80-90 it will not be warm. That is the issue I had, the bottom radiator hose was never warm until I replaced the thermostat housing.
ebay has knock off versions that are not expensive but I'm weary on using one since Lucky 8, Atlantic British or British Parts Utah only stock the Land Rover version. My local dealer said they are on back order until the third week of June.
ebay has knock off versions that are not expensive but I'm weary on using one since Lucky 8, Atlantic British or British Parts Utah only stock the Land Rover version. My local dealer said they are on back order until the third week of June.
Rock Crawling
Joined: Jan 2021
Posts: 461
Likes: 75
So this's what I'm noticing for the past few days. When the ECT is 215-220 F, the t-stat temps is 80-120 F but as the ECT drops, the t-stat temp increases. Yesterday, ECT was 180-190 F and t-stat temp was as high as 170 F. Today however, ECT was 180-190 F and t-stat temp went as high as 180 F. Seems the temp differential gets smaller when idling for extended periods and increases when driving, meaning as ECT increases, t-stat temp decreases. Still no change with the hoses not deflating.
