caddy over heat

[Papa_Jon]

OK I got given a 99 sts by the guy that owns the company I run. He has had Radiator,Water Pump,T-stat replaced. Still over heating after you drive it for 15 miles ONLY if your running the A/C. Once you turn a/c off it starts to cool down.
I have try pressure test cooling system holds good pressure. flushing the cooling system. Anyone know poop about a North star beside don't buy one lol

 

[sweetk30]

1 or 2 cooling fans on the rad system ?

if 2 then gm has set them up as 1 fan main for engine .

then 2nd fan if for over heat or a/c use.

so if hot unless you use a/c then i bet fan #1 not working.

now same is true for not cooling down with a/c

if you have to much heat and then add more to the system with a/c there could be a lack of cooling from the fans. like 1 not working.

if you can get your hands on a good scanner and watch the data stream to the computer and see what the temp comands fan on and see the temps and possible find a bad temp sender unit not telling the true temp for false on/off temps then that might be the problem also.

 

[Papa_Jon]

it has 2 fans both come on when car is running .. which i thought was wierd but i guess with a north star thats normal...I have hit it with my gauge and it reads a normal temp
190 and when it starts to over heat goes as high as 250

 

[Yay!Gurrr]

Make sure you follow any special coolant fill and bleed procedure. May have air pockets.

 

[Papa_Jon]

It was a the purge line... was cloged stop the over heating sold car the free car for 4500