Alright, I have some overheating issues with my car and I've come for some advice here. Its been driving me crazy. I have a 2003 Monte Carlo with the 3.8 engine. I have 202,000 miles. In the last few months, the coolant, thermostat and upper radiator hose have been replaced. I've also replaced the radiator cap. The coolant is the green coolant. But sometimes the coolant level gets low.

What's weird is I don't see any leaks and my heat works well. There's also no milky oil or white smoke. The longer I drive it, the hotter it gets. It does good for a while though. Especially when it's pretty cool outside.

Any thoughts on what else it could be? Thanks

 

try a lower temp thermostat. Do the fan's turn on after >200 degrees? Radiator might have sludge coating the inside preventing thermal transfer

 

Yes, the fans come on at their normal temperature. I thought about that too, but don't see any sludge that I can see

 

After changing my LIM and UIM, my car seems to idle warm, espeiclaly if I am not driving, gridlock driving make the car get warm, so I put in a cold thermstat seems to have done the job.

 

I might try the cooler thermostat. I haven't changed any of the gaskets yet though.

 

I changed out my thermostat to a 180 and it seemed to help, but it's still going 1 or 2 notches past halfway. I'M thinking about changing my radiator next. Is that the right thing to do? Maybe it can't handle the heat anymore.

 

Upper and lower intake manifold gaskets will usually cause this type of issue I had to replace mine I couldn't get around the McDonalds drive thru without it over heating and the fans going nuts.
Sometimes a good coolant flush will help too.

 

I'd use a scan too with live data - guess my 2002 Grand Prix GT (3800 NA) temp gauge and my 2005 Impala's fuel gauge make's me leery of gauges in this era. This can then tell you if the fans are turning on at the proper time.

X2 LIM. Check to see if they are the black plastic. This will cause oil to mix. Maybe not a lot in the beginning.

I guess a lower t-stat could help a bit or give you a longer time before reaching a critical temp.

As far as the radiator - they wear out/get clogged/get dirty in between the fins. How long has your coolant been switched?

 

Right, I've read about the gaskets, I might have to check them.

And my coolant was flushed and changed out in July or August I think. So far changing to a 180 has helped some.

I'm getting a few recalls fixed on my car tomorrow. The kignition and the underhood fire recall.

 

I meant to say my coolant was flushed and changed to the green in July or August of this year.