Except for one weird thing, my MY20 P300 has been mint (knock on wood). Whenever I take it offroad, my coolant level in the reservoir tank drops. I was in for an oil change 3 weeks ago and mentioned that my coolant warning popped up and I topped it off. I asked if they could check for leaks. LR found no leaks and they ran a pressure check. I then went offroading last weekend with Gavin C. We spent a good 2 hours in lo range doing typical off-road stuff. My temp gauge never moved, hung out in middle. The temperature outside was 52 degrees, I had my climate control set to 68 degrees and no A/C running. On Monday, something told me to check the coolant level, and to my surprise, I was at half of the tank. I took it to LR today (they offered me a car or uber but I waited it out.) and explained the issue. 2 hours later, they came back and could not find a leak. They ran pressure checks and looked for leaks and found nothing. I even asked them to check the connection to the heater core to see if that was causing coolant to spray into the car. The service advisor and I are stumped. When I am driving it normal, the coolant level hasn't changed. All we can think of is the engine was working overtime offroad but I dont feel that I working the engine too hard with what we were doing. We did stop often to inspect our next line and I kept the engine running but again it wasn't 100 degrees out. Any suggestions or thoughts on why I tend to burn coolant when I am in 4lo would be helpful.

 

I don't know if I'm smarter than you, but I'll take a shot at this.

If you are finding the need to top off coolant but the system passes a pressure test and the heater core has been inspected AND there are no signs of cross contamination in the fluids...It might have been low to begin with and you are merely bringing things up to normal capacity. It's rare, but sometimes they ship slightly under-filled due to an air pocket.

Keep topping it off and watching it over the coming weeks. Also note any leaks under the vehicle when parked.

 

I've no idea what it could be.

*dramatic reenactment

 

There was a technical service bulletin out about this issue. Someone posted it back in October, maybe you can look it up but here’s the TSB number
N576NAS1 - Service Action - Coolant Level Sensor Loose

https://landroverforums.com/forum/20...-loose-108855/


File Type: pdf

N576NAS1 - Service Action - Coolant Level Sensor Loose _ TOPIx.pdf (284.6 KB, 79 views)




 

One thing to consider. When your off-road the one thing that works hard is the transmission. It also has a cooling loop to the engine coolant. Now if it was leaking into the transmission, it would also leave traces of transmission fluid in the regular coolant. Your cooling system gets to max workout when everything is working hard and not too much air going through due to mass airflow from speed. The system in general is as loaded up disposing of heat as it can be. Modern cars seem to have miles of cooling lines, some flexible some hard. The flexible lines do expand and contract as they get hot and cool off. Usually, it is best to check what the true system level is when the car has had an hour or so to cool down and the system to return to normal standing temps. We love sensors, but automobiles in general use the cheapest they can get by with, so they fail on a regular basis. Airplanes are chock full of über expensive sensors and they fail as well. I think my lifespan has been decreased by the stupid things. You always have to react as if it is failing. The T-28 I flew in training was far older than I was at the time, in fact so old, my step father was an instructor in them when they where newish. They had a chip detector, which light up if a piece of metal bridged the gap and made continuity. It was supposed to warn you your engine was coming apart, bad thing. I must have done 15-20 PEL's (precautionary emergency landing). The engines, which where older than the airframes by a decade or so, pretty much the best thing they did was make metal. I had two complete failures in 180 hours, not so good.

My long winded advice is; next time, take a break and see if the level comes back up when it cools. If it has fluid and you get a light, throw a sensor at it, they are cheap. After it cools and there is no pressure, put a twist of paper towel dipped into the fluid and see if the upper part comes back slightly oily. Transmission fluid is usually reddish in color, rather close in color of the special "Rhino Urine" expensive coolant that Land Rover uses. Touch it and rub it between your fingers to see if it is oily. Coolant is more sticky.

 

Thank you and I will keep my eye on it. This is the second time that we topped it off so hopefully it is good to go.

 

All good stuff and I will follow your advice.

 

Thanks for the suggestion. I do know its not a sensor issue as the sensor is not triggering when I have a full/half tank, the issue seems to be loss of coolant.

 

Interesting problem. It's a closed system so the coolant is going somewhere.

I've had similar issues with 2 Jags but I don't know if I'd jump to any conclusions based on yours being off-road related and the water temp stayed normal.

First time I had a leak in an XF, they checked and found no leak. I asked them to check for exhaust gas in the coolant to see if the gasket was blown. That came back negative. They topped it off and sent me home. 2 months later it was low again. They checked for leaks again and found nothing. This repeated until I got tired of it. I Simple Greened the engine and dried it. Ran it really hot and watched. Didn't see a leak but, sure enough, there was a slight residue building next to one of the hoses. The leak was so small the mist was almost invisible. They replaced the hose. No more low coolant. Ironically, the head gasket blew about 10k miles later and the engine had to be replaced (unrelated).

Second time was an F-Pace. Same story, they couldn't find the leak. I found the very small pinhole leak myself same as before. My service advisor said something like, "of course, these plastic JLR hoses are crap".

Like I said, this is probably not helpful in your situation but I thought I'd throw it out there in the off chance...

 

Would an oil sample rule in/rule out a coolant leak into the engine?

I'm very ignorant of these things but perhaps that data would be useful. Would a dealer be able to order one as a diagnostic test under warranty.

A new engine should not be losing coolant in any way. The off-roading was in no way stressful to the drivetrain.

If the oil is sound and there's no tranny fluid in the coolant then it's got to be a hose leak. Diagnosis by exclusion.