mbates50

Checked the coolant level in the reservoir, BUT forgot to put cap back on.
Needless to say, after returning from dinner, the "check coolant" message illuminated.

I knew what it was and watched the temp rise to beginning of the red line in the temp gauge, appx 120 degrees. Stopped the car. Started again and limped to a gas station. Temp reading never went into the red, just right at it.

Put some 50/50 Peak coolant in and made it home, temp. normal

Two questions:

1. Did it get hot enough to do any damage? Car ran fine after putting in coolant. No head gasket smoke, etc.
2. Should I get radiator drained and refilled with Benz approved coolant? Far as I can tell this Peak stuff ain't the best. Car only has 23K miles

Thanks

nycphotography

Absolutely drain and flush the peak stuff. MB coolant is lifetime rated and pretty specific.

As for damage, if it didn't blow a head gasket / warp a head you're probably ok. probably.

tandan

Ditto. You did something stupid, I was more stupid. Thoughtlessly added some old coolant in my garage when I became low in my 2005 SL600. Result-- replace radiator.

mbates50

Well, look on the bright side.
At least it wasn't your engine oil you did that with

tandan

You have no idea.

Utopia Texas

There is not one of us on this forum that has not done something stupid in the past!
Here on the farm I have 35-40 pieces of machinery from weed eaters to huge diesel tractors some using diesel fuel, some gasoline and some the gas/oil mixtures. I am constantly catching myself getting ready to pour the wrong fuel into a particular engine.

nycphotography

For future reference, in an emergency, fill with distilled water only.

Then replace with appropriate coolant at the first opportunity.

Prevents the need for a full system flush.

mbates50

Dealer drained and refilled. $120 total.
I tried doing it myself, but my car is so low to the ground, and not having the right tools, could not really see me doing it myself. Can't even find the oil filter.
Sheesh, for the good old days.