Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Confusing owners manual re engine coolant

I was low on antifreeze/coolant for my 2003 Mini Cooper. Supercharged and 1.6L motor.

I looked in the manual and it gives no specification on topping off. It just said use Mini Cooper coolant. The oil section said a little more. Suggest bmw oil but at least states full synthetic. 5w30 or 5w40. So at least I know I can buy non-bmw branded oil.

But what do I do for coolant? I don’t want bmw coolant.

First, how much coolant do you need to add? If it’s more than a trivial amount, then you have a leak or other problem that should be investigated.

Having said that, I think it’s simplest to stick with the manufacturer’s coolant here. When I buy a new car, I buy one jug of coolant to go with it. That’s always lasted me for the eight to ten years that I keep my cars, so it really doesn’t matter to me if that costs more than some generic coolant from the auto parts store.

BMW does not make coolant but they do specify what properties they want in their engines so why would you not want what they recommend ? This might be a good time for coolant change and have the cooling system checked.

Aren’t this gen Mini’s known to have radiator leak issues? As mentioned I will have it checked 1st. For small amounts I usually get away with just adding distilled water, unless you are really in a cold climate.

Also, on the Synthetic oil, I am not sure if all Synthetics sold here would meet the European standard, so something else to check.

I’ll go a little off-topic

The car is 13 years old . . . it’s time for a coolant drain and refill, if it’s still the original coolant

If you don’t want to get bmw coolant, get some aftermarket coolant that meets the specs listed in the owner’s manual

How about zerex g-05 . . . ?

I agree with db, might as well have it replaced anyway. But geez about 8 years ago I bought a gallon of Acura coolant and still have it. (Maybe it should be replaced) I think I paid $10 for it so I need not worry what to put in. Also, be a little careful on the synthetic. If its the same as BMWs, some synthetics just don’t seem to adjust well to that engine. Don’t know why but seems to burn it up fast. I like Mobil 1 but its not good for BMW. Seems to me Valvoline or something worked better. Also sometimes they’ll have information in the owners manual in several places. In the capacities section, they’ll usually give the specs.

I don't want bmw coolant.

I’m assuming BMW coolant is the same product as Mini-Cooper coolant. Please explain, why don’t you want to use it? Is it b/c it costs much more than aftermarket coolants? If so, and the owners manual doesn’t list the actual coolant specs requirements, visit a BMW dealership, ask them to show you a bottle of the correct coolant for your car, and write down the specs of their coolant, which is usually listed on the bottle. Then search for an aftermarket coolant that has identical specs.

You might wonder why the coolant specs are important. It didn’t use to be that way so much, all the typical cars you’d see on the road in the 1960’s could pretty much use any basic coolant you could buy at an auto parts store. But back then all cars used the same coolant gadgets and technology and same gasket material. These days, not so much. Gaskets can be made out of different materials, one car to the next. If you don’t use the right type of coolant it can damage the gaskets and you end up with coolant weeping out of the engine, or even worse, overheating and blown head gaskets. Likewise for the materials used to construct the radiator, passenger compartment heater, coolant hoses, transmission cooler lines, water pump, coolant temperature sensors, thermostats, etc.

The two coolants that in my humble opinion are worth buying from the dealer if you’re unsure just to ensure that you have the right stuff are (1) tranny fluid and (2) coolant. It’s worth the few extra bucks IMHO. There have been too many problems caused by incorrect fluids in these two applications. These two fluids shouldn’t have to be purchased often enough to make the purchase so price sensitive as to preclude the dealer stuff.

Once you purchase a bottle from the dealer, it should list all the technical specifications for the fluid. From there you can decide whether to buy elsewhere using the technical specs or again use dealer stuff.