2006 Volkswagen Jetta VW 2.5L coolant problem

First, you need a new mechanic. The Mass air flow sensor has nothing to do with coolant and now one should have to refill the radiator everyday. The water pump could be leaking. Can you locate aprox where the leak is coming from?

Sorry, I hit send too fast. When you say oil and water were mixing, do you mean coolant was getting into the engine oil?

3 months ago I went to him and he told me that I had to change the intake manifold the whole thing and that my coolant problem would be fixed and that the check engine light would turn off. At the time, I didn't have money to fix it so it temporarily cover the crack. Basically the car was asking for coolant everyday and at one point it started rejecting it and so it was overheating all the time.
My sister tried to do a oil change and the guys at the shop told her that they cant replace the engine oil because it was cracked or something like. So she went another 3,000 miles without doing any oil change ( I don't usually use the car so I had no idea).
Now one day it was over heating and smoke started to come out of the car, and when he came to check it out it seems like some engine oil (or some oil) was getting into the coolant tank so it was mixed with water and oil.
He said we have to fix the oil cooler and the intake manifold (whole thing) so I assumed that after fixing that it would just stop asking for coolant or water but a day after it asked for coolant.
He checked it again and said that the water pump is leaking that we have to change it, and that I have to put water everyday on that coolant tank.
Then he used that machine that detects why the "check engine" light is on, and it was saying that the MAP sensor has to be changed.

Please advise me on where the problem is, because If after changing the water pump and sensor, the engine light or the coolant warning is popping up again, that would be a waste of money.

I have to be honest, you need to determine where the coolant is leaking from. Is there any white smoke from the exhaust? As far as the MAP, is the engine running properly other than the coolant issue?

He is saying that the water pump has to be replaced that s why it is still overheating. No, the smoke happened only once when it was over heating but basically no smoke when I drive.
The car drives good, it is shaky when I accelerate ( I assume its a transmission issue) but except that coolant issue it runs good.
The machine told me that the MAP sensor has to be changed to the engine check light to come off that is why I want to replace it.
I think I will consult another mechanic this week

Hi:

Without me being there, it is hard to determine if the water pump is bad. Yes, they can start leaking, but you should be able to see the leak if it is that bad.