Just changed my oil in LR3 car with a recommendation that I should change from solid 40Wt to GTX 5W30. 1 week after the change, the engine light came on as well as low coolant level error. I have added the coolant to the required level but keep going down each time I drive for not too long a distance with engine light still on.

 

Don't believe the two are related. You would be wise to read or have read the codes making light come on. Check oil fluid level, to be sure you are not having a loss (or increase - if gasket leak of coolant into oil). Coolant loss is usually loose hose or clamp, bad gasket, cracked engine head or block. Let's start with the cheap ones, examine engine top and bottom, park over fresh cardboard to spot any drips, etc. If can't find anything, you can do a pressure test of cooling system that pumps air into system, and you watch for leaks. If you suspect something like a head gasket (perhaps you have white smoke out the rear exhaust) there is a chemical test that you can buy from auto parts supplier that will test for exhaust gas in coolant.

Carry a case of bottled water or several jugs of 50:50 premixed coolant with you so you can top off until problem is resolved. Do not drive with low coolant or you will have major engine damage from overheating. You may wish to invest in your own code scanner, that can read codes and reset the check engine light.

Where are you located? If in a very hot area, the owner's manual might spec a heavier oil.

 

I have never heard of using straight 40 in an LR3. Dealers here in TX, where it is very hot always used 10W30, although LR calls for 5W30. Before I changed to something else, I would wonder who, and why was that oil chosen in the first place. I use Royal Purple and a Royal Purple filter with good results so far.

A common failure point on these is a crack in the thermostat housing, the coolant evaporates from the heat, so the leak is not obvious. It would be wise, very very wise to have the cooling system pressure tested for leaks. You might also have a sensor problem, or something else.

Is the temperature normal, high, low, how much, and how fast is it leaking down. These are all questions that are worthwhile investigating.

 

Thanks all for your contributions and suggestions. I think because the coolant level was low so the error message was stored in the memory and probably took time to rectify. The coolant level is normal now without any leaks. As for the Engine light being on, a friend advised that I remove one of the battery terminals overnight and fix in the morning. Crude though! I did that and the light is off without any problem. I live in the hot environment and i reckon the 40Wt works better. The temperature is normal and no more loss of coolant.

Ajibola

 

1. You have a valuable vehicle. Invest the time to download the factory owner's manual and use it for oil advice. See Land Rover site.

2. You cleared the codes, but also any idea of what caused them. Next time, go by just about any auto parts store and have them read, write down the numbers. You ar making repair to the truck more likely, and more expensive.

 

you only clear codes by fixing them. not disconnecting the battery.