00 cadillac deville overheating

[Jeff_125]

I have a 00 deville I changed the water pump and the housing the thermostat and it's housing the radiator and the upper and lower hoses. The car will idel with the heat on high for a hr or more with no signs of overheating.. But soon as I drive it BANG...it overheats. The coolant isn't bubbling out the resovoir at all But it reads on the dash SHUT ENGINE OFF. I'm not understanding this and I don't want to just get rid of it. I had this car for 5 yrs and have yet to have any major mechanical issues with my car. We did the headgasket test. I don't know if the block is cracked or from all that overheating from before something deep down is damage. The car sounds good running the engine dosent have any knocks. You can't even tell the car is running when it's on besides hearing the fans running. It has 200000 on it and it's mostly highway miles. I really need some help on this one.

 

[mymutter]

You either need to bleed the air out of the system, or you could replace the coolant tank. (there is also a screw at the end of the purge line that you need to clean and replace.).

are you losing coolant? is the engine oil still look like engine oil black, no moisture, if it has coolant in it it might look like chocolate milk? is there an oil film on the cap to the resovoir? is there moisture, like smokey exhaust when you go to drive it or it's running, or even at first start?