1999 chevy tahoe 5.7L vortec 350 new thermostat,new radiator,new waterpump.still overheating?

96 to 99.. Vortec,,,, or any 350 short block,,, use you vortec heads

Your best bet is to get a fuel pressure gauge and see if you have the required pressure at the test port.

Did they replace the thermostat? If so check to make sure that nothing is plugging the radiator or heater core?

Sounds like it could be a dirty or faulty idle air control valve.Take it off and clean it with a wire brush and a non-chlronated brake cleaner or replace it with a new one.Make sure you reset the computer after cleaning or replacing the valve.

The regulator located inside the plastic intake plenum? There is no hose. They just work off the vacuum present inside there.

It sounds like your radiator is quite stopped up with corrosion and or other foreign material. Try flushing it yourself first and if the problem persist take the radiator to a shop and have it boiled out.

First check that the thermostat was installed correctly. It will not work properly if it was installed upside down. If this is the original radiator, it most likely is plugged up with deposits and corrosion. It needs to be replaced with a new one.

while your car is running and, warmed up; squeeze the top radiator hose; if you feel coolant flowing your thermostat is open and your waterpump is working if your waterpump fails it usually drips coolant out of a "weep" hole on to the ground first.

Overheating could be a combo of many thing's.If your thermostat is stuck you will have no circulation which will cause overheating.Also if your eng. has alot of miles your water pump may be in need of replacement.Listen for your radiator fan motor and be sure that's working and also check to see if you radiator is good.If your loosing antifreeze because of a headgasket you will see a white cloud out of the exhuast because it is burning it and sometimes you also get a little in your eng.oil.Using a pressure tester on your coolant system will help to diognos the problem,if you have a leak some where it will not hold pressure.Sign,s of a bad waterpump are poor circulation and a antifreeze leak from a vent on the waterpump.Be sure the eng. is cool before working on it.Hope this was helpfull.

sounds like u might have a blown head gasket is your oil milky colored