Coolant issue: perhaps undue paranoia.
 

Having recently acquired a pristine low mileage 450 SEL, I had a local tech flush and refill the cooling system. Under the advice of a knowledgeable neighbor, I went down to the local MB delaer parts dept., and first purchsed a gallon of MB brand coolant. You know, specially formulated for the aluminum head engines.

Well, when my tech did the flush and refill, he afterwards advised that the coolant provided wasn't enough, so he topped-off the remainder using other coolant in the right mixture of coolant and water, etc.

I'm not overheating or anything. I'm in South Florida (90 degree temps), and my gauge usually at cruise is a bit above the 80 mark, and under stop and go going towards the top of the "8" or I guess 90 area.

My paranoia is: will the use of some non-MB coolant cause a head gasket leak or blow-out? Engine has 59K miles. Just want to avoid problems with a good and tight engine.

Please advise. Thanks.

I've read that it's a bad idea to mix coolant.

MB's coolant is unique in that it has a ph of 7, or neutral. All other coolant is not.

Using the other coolant is bad on the water pump, seals, plastic, and rubber parts.

I'd drain, flush, and refill.

Mixing coolants is not a good idea and the MB coolant is specially formulated to protect the alloys and seals used throughout, but these are PROLONGED effects of use (or non-use)!

You can go merrily along for now without worrying about doing permanent damage to your engine...just get the system flushed and refilled as prudently as possible...buy enough MB coolant this time...and have the flush and refill done at the tech's expense!