Coolant temp too high at idle
#1
01-02-2012, 05:38 AM
Coolant temp too high at idle
This all started after I had the head gasket replaced.
As long as I'm moving, the temp gauge stays at 3/8 where it's always stayed. When I idle for more than 5 minutes, like in a traffic jam, the needle starts to move up and goes over 1/2 before the fan comes on and the temp comes back down.
I've found fan controllers online, but there are several types and can't find anything in the Haynes book talking about where the fan controller is located, or what it looks like.
I guess question 1 is: is this temp issue a problem, it didn't act like this before the head gasket blew out. It's getting into the 250 degree range when idling.
Question 2: where is the fan controller, so I can tell what type to get to replace it.
As long as I'm moving, the temp gauge stays at 3/8 where it's always stayed. When I idle for more than 5 minutes, like in a traffic jam, the needle starts to move up and goes over 1/2 before the fan comes on and the temp comes back down.
I've found fan controllers online, but there are several types and can't find anything in the Haynes book talking about where the fan controller is located, or what it looks like.
I guess question 1 is: is this temp issue a problem, it didn't act like this before the head gasket blew out. It's getting into the 250 degree range when idling.
Question 2: where is the fan controller, so I can tell what type to get to replace it.
#4
01-28-2012, 06:03 PM
My 98 does this too after a coolant flush and same for a few (3800)Impalas I have driven/sat still in for 30 mins or more. In 2000 they completely changed the engine and trans but In 99 they did relocate the coolant resivior tank from behind the headlight to the strut tower by the belts. IIRC the fans are controlled by the ECU located inside the airbox. Haven't found anthting else that suggests the controler was external. By any chance did you put orange coolant back into the car when you did the head gasket?
*Edit 99-2000 had an issue with the radiator filler neck and radiator cap? when's the last time the radiator cap was tested/ replaced?
*Edit 99-2000 had an issue with the radiator filler neck and radiator cap? when's the last time the radiator cap was tested/ replaced?
Last edited by Merc6; 01-28-2012 at 06:16 PM.
#6
01-31-2012, 01:34 PM
How closely did you compare the new head gasket to the old one?
The reason I ask this is because, if there was a difference in the old gasket as compared to the new one, smaller hole for coolant to pass through could affect circulation volume and increasing engine RPM may just make up for a smaller opening.
I'm speculating here and am not positive that this is what may have happened.
By the way what happened to cause you to need to change the head gasket?
The reason I ask this is because, if there was a difference in the old gasket as compared to the new one, smaller hole for coolant to pass through could affect circulation volume and increasing engine RPM may just make up for a smaller opening.
I'm speculating here and am not positive that this is what may have happened.
By the way what happened to cause you to need to change the head gasket?
#7
02-02-2012, 05:18 PM
Didn't check the gasket that closely.
Replaced the head gasket because intermittent overheating. Kept getting worse, finally catastrophic overheating. Replaced thermostat, then water pump, then took it in and had it checked. They said head gasket.
Replaced the head gasket because intermittent overheating. Kept getting worse, finally catastrophic overheating. Replaced thermostat, then water pump, then took it in and had it checked. They said head gasket.
#9
02-03-2012, 11:50 AM
This came from gaownersclub.com and is primarily based on the 3400, but it should be essentially the same for your car.
3. The coolant MUST be bled of air ('burped') EVERY TIME the level has gotten lower than the bottom of the reservoir. Open the hood and face the engine. On your left is the right side of the car (everything about the car is named as though yer sitting in the driver seat). See the water pump? It's front faces car right, and its 'back' is to the engine. On the back of it a black metal tube sticks straight up, about 1" diameter by about 6" tall, Welded to this tube is a thinner tube that runs horizontally in front of the engine and eventually connects to the t'stat housing (on the back of the engine, car left). On top of the black tube is a pair of hex-headed fasteners, which are black-painted brass. Hold the larger/lower hex still with one wrench, and twist open (counterclockwise) the smaller/upper hex (the bleed screw). Fill the reservoir with water or your AF mix, until it just starts to dribble out the bleed screw. Tighten the bleed screw. CAREFUL!! These parts are brass so they never corrode, but that also makes them soft and susceptible to stripping of threads, rounding of hex corners, and snapping of the bleed screw (which is a PITA).Voila! The system is bled, and the level of coolant is right at the 'Full -Cold' mark on the reservoir. Now drive the car and get the coolant to operating temp, so it circulates thru every part of the engine, rad, and heater core; the air remaining in the system will become trapped in the high part of the system, which is that horizontal-running tube across the front of the engine. Allow the system to cool, open the reservoir cap, open the bleed screw, fill as before, and close the bleed screw. NOW yer done!