2023 Defender P400 with 2000 miles and the low coolant level warning light started coming on around the 1500 miles mark. Added coolant and warning is back on 2 weeks later. Added more coolant and two weeks later same warning. Took it to the LR dealer to have them check for any leaks, and they could not find any and said new engine probably clearing the air in the lines.
2 weeks later same warning, decided to take it to a different LR dealer who discovered the leak coming from the water pump. Has anyone here experienced a bad water pump on their Defender?

 

I think it is more important to find out what made it a "bad water pump"?!? Was it something simple such as a bad seal? Bearings? Belt slipping etc...Do you keep the car in the same spot regularly? Is there any residue (spots) on the ground? Did you smell any burn-off? More info you can uncover, the easier it is to diagnose.....

 

I could not sense any belt slipping while driving or during idle. The car is usually kept in the same spot but I never noticed any spots on the ground; remember it has that large pan underneath the motor but I suspect the pan will have spots on it, and I will ask the dealer about that. I did smell coolant burn-off and I agree with you that it is important to find out what made it a bad water pump. I will post more findings after the repairs are done.

 

I had a '17 Grand Cherokee SRT a couple of years ago that had a pinhole in the radiator...I could smell the burn-off, and that was about it..No spots, drips or leaks. It was actually others on an SRT forum that pointed out the similar issues they were having that turned out to be faulty radiators.

 

There is a LOT of cladding, fiberboard, front skid plate (if installed), etc. underneath the engine compartment. Unlike my old 1963 Series IIa which leaked a LOT and you could tell where the leak was (sometimes even color!) by putting cardboard under it overnight, the L663 Defender likely blocks most leaks. I suspect the fiberboard even absorbs it to a certain limit. So, finding stuff underneath isn't the same as my "old school cars". I'll have to confirm on TOPIx the locations as I'm not that motivated to climb under to check.

But, I agree with @ZL1Ragtop . Why did they diagnose a leak there? A fault code was probably thrown with the dash warning, but fault codes NEVER tell you exactly what's up. Dealer A just said "whatever" and Dealer B went thru a triage.

 

I had a similar coolant leaking issue, took the car back to the dealer 4 times, and I just got the car back last week, hopefully, this time they fix it.

I had this low coolant warning a few months ago, started off with one or two warnings every second day or so, I checked the coolant container and the coolant level was low. So I took the car back to the dealer for the 1st time they ran a pressure test, could find any problem, top up the coolant and let me go.

A few weeks later, the warning appeared more frequently, but the coolant level under the bonnet was actually ok most of the time. So I took it back 2nd time. They spent a day checking and testing, gave the car back in the afternoon, and told me everything is good now.

I drove the car for about another two weeks, and things started to get worse, coolant have to be top-up every second day. So I took the car back to the dealer 3rd time. They found a small crack in the coolant container and replaced it.

While I thought this is the end of it, the low coolant level reappeared a few days after I got the car back from the dealer, I end up leaving my defender in the dealer's workshop for 2 weeks during the xmas break for them to carry out a long-term test. They found a leak in the radiator and end up replacing a new radiator...

So I hope this time they have fixed it for good...

 

Wow, what an ordeal. I am glad yours is finally fixed. I hope they get mine right. Supposed to be ready this week.

 

my 2021 had a bad water pump before I owned it. Still dealing with the low coolant level and NO ONE can figure out where its coming from, even pressurizing the system for hours at a time, yet when I drive it for more than an hour, the low coolant issue happens. I have 16k miles on mine

 

Did they replace the bad water pump? Another question since you are still dealing with the low coolant issue: are you having to constantly add coolant to the reservoir? What about the coolant sensor? I am astonished that no one can figure it out. Might want to check your state's lemon law or ask for a buy back.

 

yes according to service records it was replaced - you can still smell the coolant burnout too. the closest dealership to me is almost 3 hours away, but I luckily have a landcover specialist/mechanic across the road from me. Right now it sits on MINIMUM while driving, but overflows above MAX when engine is cool. Last time I filled it up was last week. I dont drive far distances really. I bought my defender from Carvana, but have the regular warranty and the Carvana extended warranty too - there are also sensor issues that have been common on these will it gives false warnings (not my case though)