Hi,
I just bought an 03 GP GT with 109K on it with the non supercharged 3800. The previous owner has all service records and really took good care of the care. I see this past fall the coolant was flushed, a new T-stat was installed and the system was pressure checked. I question though the coolant temp as shown by the gage. It looks like the T-stat doesn't open until the gage shows anywhere between 220-230. The temp drops down to one tick above 210 which I assume is 215 and will stay there for a couple minutes then jump back up to 220-225. Then it comes back down to 215 and does this back and forth for 10-15 minutes.
I have a 25 mile commute to work and I notice when I come back into town at a stoplight the temp will drop down to 210 then go back to 220 or so. For the most part, it stays at 220. Keep in mind I'm in WI and the temp here was 5 degrees F this morning. It acts the same way when its 40 degrees to.
I've checked the coolant and it is full and clean, the oil has no trace of antifreeze in it, I see no leaks, and I tried to bleed the cooling system with the bleeder on t stat housing. When bleeding, the engine was at temp, the t stat was open and the rad. cap was on. I tried it twice but got no bubbles. I still think there could be air trapped somewhere. I've also replaced the rad. cap. The heater works awesome also.
I talked to a guy at work today with a Bonneville that acts pretty similar. Does this sound normal for a 3800 or should I be concerned? BTW, the upper intake gasket was replaced about 20K miles ago but the LIM is the original from what the service records show. Let me know your thoughts.
I'm a first time poster on this site but have been reading it quite a bit lately.
Thanks, Bob
