Soundsvague I know, but I am just trying to figure this out... and its boggling. Car runs fine, watching temp gauge, it doesn't go up to regular operating temp unless sitting idle for a long period of time. That being said, when it does go up to operating temp, it still fluctuates reg temp/ cold (around 160). The heater isn't blowing very hot at all unlessthe car is under load. Coolant is full, thinking bad thermostat ( stuck open maybe?) Any guesses?

 

You are sure there are no coolant leaks, right? My car did the same things and it turned out to be a little elbow pipe that broke, causing coolant to spray everywhere

 

Those are brand new

* update*

I opened the hood and the upper radiator hose sucked in on itsself, I loosened the radiator cap and it immediatly filled back up with coolant and the heater got warm. I felt the hose and it was full of fluid after the radiator cap got loosened.

 

Did you bleed the system?

 

No heat and the car temp being low would point me to a open thermostat. It also sounds like you have a lot of air in the system with the upper hose sucking itself in. I would change the thermostat and bleed the cooling system really well.

 

I'll be watching this thread...my '03 is behaving in a very similar way as what you described.
I've read about checking the elbows so I will visually inspect...but I dont see steam and no leaks under the car.
I'll change the stat and observe for changes.

Has the problem now gone away for you ?

 

and the not paying attention to the forum award goes to.....

 

I don't get your comment...is that thrown at me or to the original poster ?
I'm just wondering what the update might be...sorry if I missed something.

Thx
John

 

https://montecarloforum.com/forum/en...-engine-26459/

^^^I am pretty sure that he is in the process of getting a new engine. Just click that and it should get you up to date.

 

Lmao... greg would be correct.

The problem was, the water pump was leaking and the upper intake manifold had a leak to the inside.

You should change that gasket every 60,000 miles.

I do have a new engine now, but its sad that I had to sacrifice an engine to learn that