Cooling System Issues

**CSteen85** · 06-22-2010

Hi Guys,

I haven't been around in a while... I was spending too much time/money on my car and there was really nothing wrong with it at the time, lol. I'm just a perfectionist, but I had to stop trying to make a 14 year old car perfect.

Before I get into what's wrong, does anyone have the short answer to: How do I empty the coolant reservoir?

Recently, I started having issues where my car would reach operating temp and then ONLY at a stop light, the temp would quickly rise ALL THE WAY up to just about the red section. I started to get really nervous that it would overheat and I even turned the car off completely while sitting at a light every once in a while.

Anyway, last night on my way home (about a mile drive) my low coolant light came on, which had me totally scratching my head, because I had just topped it off and I didn't see any puddles anywhere on the ground. THEN, I noticed coolant was pooling up on top of the intake. I assumed my gaskets needed changing, but then I noticed some bubbles coming out of one of the screws on top of the gasket. I torqued it down and then noticed sludge building up on my radiator cap and on the neck of the tube. I decided to flush out my cooling system.

I think I did alright, but all I had on hand was the green coolant. So, I mixed it with water and poured it in and it only took about half the gallon. How much should I need to fill it completely?

My other issue is, there's still the orange coolant in my reservoir tank. I can't figure out how to drain it so I can fill it with the green coolant. Any ideas??

BTW - since I torqued the intake screws, the top is dry.

**Silver GTP** · 06-22-2010

My opinion is still the same as last time this came up. The LIM gasket needs to be replaced. With the GM 3.1, 3.4 and 3.8 V-6's, it is not a matter of if, but when it will go. I have 2 cars that I am doing this repair on this month. You should try and get this taken care of ASAP or it could end up ruining your engine. Coolant and oil mixing is not good for making your car last. Since you have the N/A 3.8, I would replace the upper intake while you're at it. The Dorman one comes with all the gaskets needed for the upper and doesn't cost that much more than all the gaskets bought separately. Good luck.

**2000 Grand Prix GT Blue** · 07-28-2010

I dont have that same issue but i have a similar one.. one day my 2000 grand prix GT 3800 overheated into the red zone in my driveway. right away i changed the thermostat and did a flush and fill just to be safe. Since then it has always run hot. driving at about 40 mph it stays about 210 -215 but when idling or slow driving it runs anywhere from 210-230. i recently changed the water pump and the coolant temp sensor and same problem occurred.. i thought maybe it had an air pocket in it but ive bled it out several times and tried to burp it but nothing has helped my problem. It is 80-90 degrees outside right now... is this normal or can i do something to bring the temp down below 210? PLEASE LET ME KNOW! thanksss

**Widetrack** · 07-28-2010

Sounds familiar. 1997 GP 3800 SE still rolling at 175,000. Cooling fans on radiator don't come on. Changed water pump and thermostat, still no fans. I believe they should come on when a/c turned on but still no fans. Going to check the coolant temp sensor and see what happens. When vehicle is moving the temp is fine as per dash guage. In slow traffic guage rises to 210/215 and fans don't kick in. Will be back.