hot hott hottt

ok im stumped, my buick gets hot. only if im in an idleing situation...i.e. drive thru, gridlock. the temp comes almost all the way up to red, then ill turn on the climate control and the temp will go back down again...what gives?

ive changed the therm. and the heater core has been flushed.

 

Thermostat, Waterpump or Airlock.

I think the Buicks had some vacuum controlled water valves as well, so you might check that.

Airlocks usually happen when you refill the antifreeze from way below normal or a complete change of coolant.

Waterpump sounds possible, so check visually for a leak near the pump housing.

Thermostat is the most likely culprit, if all the above were OK before.

My logic is this: If the engine normalizes with speed, the vacuum picks up and a weak vacuum-operated valve would open up a wee bit. If that doesn't exist on your car, then the waterpump is most likely, if its leaking. If its not leaking then the thermostat isn't opening properly, but the speed of the car is cooling the block off.

Also check for a rad hose that might be collapsing (soft, greasy, old) That could do it too. The water just can't move around and can cause an airlock.

 

My take on this is one that creates another question.

Does it cool down when moving and only heat up when stopped? I'm not familiar with your Buick or what year it is but if it's a later model it could be that the climate control is causing the cooling fan to run and when off the fan won't run.

Is it an electric fan for the radiator? If so the thermistor that causes it to run may be bad but the climate control makes it run. Often times on newer cars with electric fans the fans run all the time with the climate control but only when required with the climate control off.

If it's an engine driven fan then maybe the fan clutch is bad and the climate control is causing the water to circulate through the heater core resulting in a cool down of the temp. or the cooling effect of the condensor is assisting the radiator in cooling the water when the climate control is on.

 

Never thought about that one. Of course, I don't have one in mine.

 

i think we have it! its has 2 electric fans. the climate fan runs with the CC on and the main fan only runs when it is unplugged from the temp sensor!!!! bought a new one, im gonna change it tomarrow when the engine cools down!

 

TBird! You the Man of the day! :2_thumbs_up_-_anima

 

I'm just happy I could help. I've received plenty of help here.

 

ok im getting frustrated....the sensor has been replaced and still nothing.

if i am moving it doesnt get hot.
if i am sitting for a min or two it starts to climb
if it starts to climb and i turn the climate control on while sitting it drops back to normal (fan turns on)
if i unplug the sensor the fans come on.

HELP!!!! :banghead3:

 

You said the heater core was flushed, but what about the rad and engine?
You'd be amazed at what can collect in a cylinder head.
Or not, I don't know!

 

yeah... but the issue doesnt seem to be coolant flow ... because when the fans do come on it drops to normal very quickly, so something is preventing the fans from turning on as they would normally.

 

is there a relay in the system that connects to the temp sensor? i don't know about "buick specific" but i would guess there would be something like that somewheres in there.

 

Maybe the thermostat is stuck, or sticky?

 

try burping the system like someone suggested also, could be an airbubble in the system. or just wire the fans on all the time hehehehe

 

one of the guys here in town that is part of the impala ss club said there is another sensor that is between #6 and#8 cyl's that is the one that siganls the guage. we hooked an obd 2 up to the comp and at 225deg the fans come on without help. but the guage is reading in the red. he( the mechanic) says the redline on that guage should be 240-250 deg not 225 so it appears i am either dealing with a bad reading sensor or a bad guage. but now i have bigger more pertinant problems..

...i have a loud rear-end ( no fart jokes... im being serious). it started as what i thought was tire noise when i bought the car. and it has recently gotten louder and louder. today it is now loud enought to hear over the radio ( at a normal level). im hoping it is something simple like rear wheel berings. and not something more expensive like a rear end rebuild. Lord willing ill be ok. i dropped it off at the shop this evening. :banghead3::banghead3:

 

good luck..... cause i sure as hell don't know whats going on in buickland!