What does it mean when your car coolant is brown and thick?

Answer 1

It could be that it is neglected coolant that is rusty, However, engine oil could be entering the cooling system via a cracked head gasket. Check the engine oil dipstick and oil filler cap. If there is a white milky substance on either. see your mechanic right away! Do not run the engine until the problem is corrected. that is an excellent answer but you mite try draining it and flushing out the system until you get clean water coming out let it drain empty then put an anti rust and

fresh coolant in and see what happens, you MAY save some money?!!! That is a good idea IF it can be confirmed that the coolant is not contaminated with oil.first. This is where a qualified mechanic with proven tests and equipment can save money. i was a mechanic for 40 years