ok on my 91 3.1 r/s while sitting at idel "like thru a drive thru" brgins to boil over into the radiator reserve tank,.making a loud boiling noise.

So im thinkin perhaps somethin is wrong with my thermostat! not opening properly.,i put in new water pump few months ago and new hoses.,

Does any one have any exiriance with what im talking about?

 

When your car heats up to about 220 put your hand on the top radiator hose in the middle and see if you can feel water passing through it. does it just do it at idle or while at driving speeds as well. Also check to see if your fan comes on could be a bad fan motor.

 

pressure test your cap, too, and see if the spring has gotten weak...

 

spring?? do u mean in the thermostat??

 

there's a spring in the cap, too. its what lets the water go into the overflow tank only when its hot. i would guess bad temp sensor before bad fan motor. but, you never know. what does the temp guage show when it starts doing that?

 

WELL THE TEMP GAUAGE SAYS ABOUT 210 / 220 FAN DOES COME ON AND COOLS IT DOWN BUT I SAW SOME WATER BUBBLING OUT OF THE CAP ..

wHERE IS MY TEMP SENSOR AT??

WOULDENT IF MY THERMO WAS NOT WORKIN PROPERLY IT WOULD BE CAUSE FOR BOILING OVER TOO??

 

that seems about right... have your cap pressure tested, or for the $5 or so, i'd just replace it...

 

I don't and never did like the stock temp ranges. The V6's are more responsive when kept more in proper range. Id get a 195on -185off switch or do some cooling mods.

But sounds like your rad cap is old. Just replace it. Or your system was just tad full and adjusting for the climate changes and needed to spit osme water out. Could watch your over flow tank level. Cause you can hear it when it spits some out. But you won't notice it suckign it back up, unless you watch for it. quiet often once cooled down it will suck about the same ammount of water back in that it spits out.

now if its spitting out so much that the over flow tank is dumping water on the ground in large ammounts....... then id say thermo stat, bad rad, some other heat problem.

 

The fan temp sender for the 3.1's, is the same temp sensor for the ecm. If your ecm's reading it fine, then its fine for the fans.

I would guess.
Rad Cap
T-stat
plugged rad
Bad water pump