2019 GLE400 faulty thermostat?
Thread Starter
Junior Member
Joined: Jun 2019
Posts: 42
Likes: 2
From: NJ
2011 Mercedes E550 Cabriolet Sport, 2019 GLE400 4MATIC
2019 GLE400 faulty thermostat?
Good Afternoon everyone,
this may be a common question, but I do not see it on this forum for some reason. Recently I had a low coolant message on my car, I filled the coolant and the message disappeared…but It is taking very long for the car to get up to operating temperature and i am noticing gears are slipping or not shifting like normal …is this air in the coolant or is this a faulty thermostat? I only noticed one time where the gauge dipped to about 70C before coming back to temp while driving …the car runs at temp and doesn’t go above operating…but the car blows warm not hot air through the vents…I know the dealership is going to try and get me for a flush and a thermostat replacement …I want to know if this is the correct approach or if this could just be air in the line?
...so I took it to the dealership and they convinced me to do a diagnostic, instead of the thermostat repair... dealership told me it cant be the thermostat because car isnt registering any codes for a faulty thermostat? ...They said the hoses going in to the radiator is 180 degrees but coming out is 80 degrees...they told me it is a blockage with the silicates rupturing in my coolant system...but that would only explain the cabin temp being wrong correct? would that effect my temp gauge and performance? it still doesnt get up to temp for a while, and if I cut the heat to the cabin it still takes a while to heat up. They want to replace everything, i still think it is a thermostat issue and they're just selling me on parts and labor. What is your guess? Did mercedes really bungle this design that bad they have beads that can rupture in their tanks?
thank you,
skbrod
this may be a common question, but I do not see it on this forum for some reason. Recently I had a low coolant message on my car, I filled the coolant and the message disappeared…but It is taking very long for the car to get up to operating temperature and i am noticing gears are slipping or not shifting like normal …is this air in the coolant or is this a faulty thermostat? I only noticed one time where the gauge dipped to about 70C before coming back to temp while driving …the car runs at temp and doesn’t go above operating…but the car blows warm not hot air through the vents…I know the dealership is going to try and get me for a flush and a thermostat replacement …I want to know if this is the correct approach or if this could just be air in the line?
...so I took it to the dealership and they convinced me to do a diagnostic, instead of the thermostat repair... dealership told me it cant be the thermostat because car isnt registering any codes for a faulty thermostat? ...They said the hoses going in to the radiator is 180 degrees but coming out is 80 degrees...they told me it is a blockage with the silicates rupturing in my coolant system...but that would only explain the cabin temp being wrong correct? would that effect my temp gauge and performance? it still doesnt get up to temp for a while, and if I cut the heat to the cabin it still takes a while to heat up. They want to replace everything, i still think it is a thermostat issue and they're just selling me on parts and labor. What is your guess? Did mercedes really bungle this design that bad they have beads that can rupture in their tanks?
thank you,
skbrod
Super Member
Joined: Nov 2007
Posts: 500
Likes: 137
From: Washington D.C. area
16 GLE400 4matic
You had a low coolant message on the vehicle. Did you check the smaller reservoir that's under the engine cover?
Could be air in the line. I would flush the entire coolant system just to be safe.
One of my older vehicles I had a thermostat stuck open. It will cause the engine to take longer, heater doesn't produce enough warmth, and sometime it will throw a CEL of P0128 (engine coolant temperature is below the thermostat's regulating temperature).
Could be air in the line. I would flush the entire coolant system just to be safe.
One of my older vehicles I had a thermostat stuck open. It will cause the engine to take longer, heater doesn't produce enough warmth, and sometime it will throw a CEL of P0128 (engine coolant temperature is below the thermostat's regulating temperature).
Last edited by amusa; Mar 7, 2025 at 06:05 AM.
