Over heating
 

My 2000 Alero with an ld9 over heats when it sits still the temp will slowly climb but once i start moving it goes down until it reaches normal operating temp. If i crank the heat to max the car temp goes back down to operating temp. I just put a new radiator in less then 3,000 miles ago and just put a new 180* stat in last week and none of this fixed it. I have coolant pressure when i release the cap so i assume my water pump is working and my fans kick on like there supposed to. So what could be causing this air in the system? starting to go bad water pump?

plastic connector under exhaust manifold where the heater core outlet connects to the inlet pipe to the water pump

water outlet leak

head gasket

mine used to do this in stop and go traffic. but that was due to the s/c. If you are running on boost its pretty normal.

If it goes at or above 3/4, there's an issue.

If it runs normally just a hair under 1/2, and when stopped goes up slightly above half, that's normal. (185-196 should be where you're at when not sitting still)

mine goes just slightly above the half mark so I wanna try a new t-stat on mine and see if it changes it

If your Sittin in traffic it will raise and go above the half.

Rob I just changed my tstat and temp sensor.. mine still goes above half on warm days and sitting in traffic.

really, well that makes me feel slightly better. it only goes that high then you hear the fans turn on full blast and it starts to creep down once again its just scary to watch it really.

Ima change it anyways once I get the 15 minutes to do it so I know how old it is

Yeah, all up to you!

its only $15 anyways im sure I have spent $15 on worse things in my life lol

Yeah me too haha

3400 guys need to ignore any temperature/gauge positions I give. Your thermostat is 195. Your cars will run at 200-210 and beyond in certain situations, which is over the half mark on our gauges. On an LD9, it should typically stay at half and below, only rising above half if the car was shut off and restarted soon after (grocery store quick run) or if in traffic for a while.

ya it goes to almost the 3/4 line and my temp gauge got up to 238 then i shut it off.

ya definite issue

Caboose don't forget just because you changed your t-stat doesn't me it didn't fail yet some of them can fail right away before even using them

T stat is good cause my upper rad hose warms up but a new twist is i drove it around until it warmed up (195-202*) then i parked it and let it sit to see how hot it gets. It got all the way up to 238* then dropped down to 188-194* and stayed there. Now my fans were on the whole time when it was parked so what could cause this?

air in the system? I wish our canadian versions said how hot its actually getting instead of just lines

The American one doesn't have number either, he must have some sort of aftermarket gauge. The only difference in the gauge clusters is that the Canadian ones are in KMH not MPH

ya i have an after market gauge and i was thinking i might have some air in there.