2016 LR4 HSE new engine starts but temp guage spikes
 

This a 2 year long saga that seems to have no end in sight. My LR4 engine was severely damaged after a sloppy coolant job that did not replace the cross-over pipe. After a long road trip the engine was toast. Since then, I have had a refurbished engine installed which seems to be working. The radiator, thermostat, valve cover gaskets, water pump, spark plugs, supercharger gasket, and battery have all been replaced. As of right now, I think I have sunk more money into this beauty than it is worth! The problem is that the thermostat shows overheating within a few minutes of running the new engine. They have changed the thermostat 3 times, twice at the sop and once at the dealer. They have checked the harness and tested all the electrical connections. The car turns on nicely, sounds good, all systems look great, and BAM! the temp guage spikes.
They have installed a second refurbished engine (both from what I believe is a reputable company in California) and the same problem persists.
Everyone is ready to give up. I love this car. I've had two of them and I truly expected to drive this thing into the sunset of my life.
If you have ANY ideas, please share.
https://cimg7.ibsrv.net/gimg/landrov...b879cf9ebe.png
parts replaced in addition to the engine
https://cimg8.ibsrv.net/gimg/landrov...f63250e6a8.png
work done to date
https://cimg9.ibsrv.net/gimg/landrov...4b5bb98fa3.png
From a cold start it takes about 14 minutes to show overheating.
https://cimg0.ibsrv.net/gimg/landrov...3e948f1c50.png
From a hot start after a few minutes of rest and a centered guage, it took less than 1 minute to reach the top

Well, the signal is coming from somewhere. It would be interesting to see what DTCs are being thrown.

I had a similar issue after replacing the radiator on my 2015 LR4 a year and half ago.

I believe you have air in the system. These engines are very hard to clear it. The actual procedure is vacuum filling it. I bought one but I did not have success using it.

Where I found success was:
1. Filling the fluid and using the bleed screw near the rear of the engine same side as the main battery. You need for coolant to start flowing out of that port.

2. Short trips around my neighborhood going up and down hills as much as possible.

3. Shutting down the engine as soon as I saw the temp rise rapidly. If you see it rise rapidly it's not coming down. So just shut off the engine and be patient to try and drive it some more so it moves out the air.


Note: I suggest getting a ODB2 reader that connects to your phone so you can see live values of the coolant temp.

The V6 has 2 temp sensors. The rear one that is part of the rear crossover pipes and a second that is before coolant enters into the thermostat housing. If the engine's computer does not get sensible readings from the rear sensor it will give I high temperature reading to the instrument display. Problem with this is the engine may have already gotten hot before the computer kicks in to give the high reading.

If you have the GAP tool you can see the temps with both sensors. If you have a generic ODB 2 tool it will most likely only show 1 sensor and that is the rear of the engine where the coolant is coming out and is the actual temp. The other sensors helps the engine know the temp as coolant is coming out of the radiator to help regulate the electrical signal that can influence the thermostat to open or close earlier.

PM me and I can get you the workshop sections that describes this.

Best thing is to use the bleed screw, monitor the actual temps using a ODB2 tool and be patient for the system to "burb" by only driving it your neighborhood so you can stop it at anytime and let the engine cool down when needed.

Good point @keninnc .
​​​​@bigfoot2 said it was at the dealer… you’d think!?!

Frankly, this engine, though efficient needs tender hands and elevated maintenance... It surprises me its such a departure from the 4.2 and 4.4 bullet proof earlier offerings. It would not be my preferred power plant for an excursion around the world.

what is the date code stamp on the genuine thermostat they installed ? if it is pre feb 2024 it is not a good thermostat
date code is stamped on side toward engine block

Time stamp on the thermostat is march-19-2024

Used Autologic BLUEBOX and ASSIST PLUS to monitor dynamic temperature readings from both temp sensors getting consistent readings from both of them.

Front and rear temp sensors should not be consistent (they should not have same temp readings). The sensor in the back of the engine (rear coolant manifold) is measuring the hot coolant leaving the block (this gives you the engine temp reading on your dash), while the front temp sensor just below the t-stat (as I recall) is on the “cold” side of the coolant system measuring the temp of coolant leaving the radiator. Front sensor should be reading temps significantly lower than the rear sensor.


With respect to bleeding the coolant system mentioned above, be aware that you have a rear heater in this car, with coolant hoses traveling all the way back to the cargo compartment. To run the air out of the coolant system, you need to have both the front and rear heaters running during the bleed procedure - at least if using a manual bleed procedure- not sure about the vacuum bleed. I use a manual bleed procedure (taken from the workshop manual) that’s worked fine - important to raise the coolant expansion tank just a couple inches to get it above the highest bleed point if doing manual bleed: https://www.landroverworld.org/threa...-2#post-240252.

Hey Bigfoot, Any updates? Were you able to bleed out your system or do you still have the problem?

@jlglr4 would the procedure you posted be the exact same for a supercharged engine? @Riese still at it with this vehicle... we took a 6 month break to deal with other things and now determined to make the manual bleed work.