I brought my 2000 Chevy Malibu to a shop because I had what I beloved was a water pump the mechanic called me a couple hours later to say it was a water pump and I need it replaced and that my coolant was milky so I'd need a flush I said go ahead with that. A few hours later he called again saying that they had just started up my car and there was a ticking noise coming from the engine and that I need to get my oil changed I told them no not to do that because I change my own oil. Now I'm confused about this why didn't they notice the ticking noise when they were checking for the leak ? What is actually wrong with my car

No he just said milky. I was just confused about the ticking thing because he made it out to be a very noticeable problem just made me think what have you guys been doing since i dropped it off. Also the engine has been running a little louder then it used and also making a bit of a squealing noise. Its also been having a heater issue the air does not seem to heat up. And it has had an issue with the brights turning off and on while driving along with the heater going down in the fan speed. Its like its just slowing down then just picks back up.

Milky coolant indicates oil in the system, The coolant system can be checked by pressurizing the system and look for leaks. This is done without starting the car. Check the oil and see if it is milky. If it is, you may have a blown hear gasket. If you are running the car now, is the coolant "Milky? This may have been caused by a faulty water pump and replacing it fixed that. The electrical may be a lose wire on the alternator or an alternator going out. The heating issue may be air in the system. If you don't feel comfortable with the person that did the work, my all means go to another GOOD garage, explain to them tyhe issues and have them check everything out. The ticking sound could be something hitting the belt or pulley. Make sure all the bolts are tight and nothing is hitting or being hit. And have the mechanic you go to scope the engine to find the tic.