My 1996 sc Saturn is still losing coolant after being in the shop twice change the water pump sensor and thermastat

it is recommended, you will be tearing it down again to change the pump and timing belt if it fails.

Pulling plug wirs is a big mistake unless you know what your doing and you don't sound like you do. It sound like a frost plug is corroded away. You should be able to start your engine even if it had no coolant at al. the coolant only cools the engine ,it does not stop it from running.Now you need a wiring diagram for your engine to see if you have the wires in the right place.......otherwise the engine will not start ever.Worse case ....it could be a head gasket and if that is the case give it to someone whom wants a free car to work on themselves...............Ken

Inside the resovoir is the level sensor that is the one causing the light to flash.Did you replace that one?

II got a dodge 1500 4.7. The problem is, the oil cab is all green and im losing coolant all the time, there's smoke coming out smells bad, but no check engine at all. So I took it to a shop to check it they said, it's a water pump ,I changed the water pump but still losing coolant ............ so is it head gasket, manifold gasket, valve stem seal, piston rings, or something I don't know of??

It sounds as if you may have an air pocket in the system, alot of your saturn and gm vehicles have air bleed on or near the thermostat housing. As you are filling the system you will need to have this bleeder open until a steady stream of coolant comes out.

This may be the first sign that your water pump is failing. First sign is a leak. Crawl on your back under car if you can see if you can see it coming from front of engine near a pully that would turn your water pump. There is a "weep hole" it may be driping from.

What may assist in your diagnostic is a system pressure tester.This has a hand pump to where you can pressure up the system to 12 to 17 lbs and this really helps bring on hard to find leaks. You may be overlooking coolant leaking from the "weep hole" in the bottom of the water pump or a place that might become much more obvious inspecting this system under pressure. The tester also helps diagnostic by noticing if the system holds pressure for a sustained amount of time.A small leak will drop your 12 psi in a matter of a few minutes and you will continually need to pump a few more times to keep that pressure which further indicates the system is leaking down.

first determin where the leak is coming from; whether it is your radiator, hoses, or the water pump. Then change what is leaking.

Try pulling the engine coolant temp sensor, They often crack not sure why but the ceramic tip cracks makes the car hard to start, the car's idle may race while shifting gears, and often smokes. The sensor is on the right side of the engine when looking at it on the head. Easy to change and get too

If your oil is white looking on the dip stick, you will have serious damage inside the engine.