Mercedes-Benz Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
115 Posts
Discussion Starter #1
I did a simple coolant replace tonight. Here are the steps:

1. Drained old only via rad drain plug (not the block)
2. Refilled with 50/50 G-05 and distilled water (poured G-05 in first, then water, for the first combined gallon.)
3. Ran the engine - inside thermostat got to 110C, even though the block was still reasonable to the touch.
4. Elevated the front of the car.
5. Ran the engine, saw decreases in coolant level at the same time as the thermostat for engine temp started reading a more reasonable 80C, stopped engine, refilled, etc.

However, after 1 hour of on and off running, with indicated temp at 83-84C, I'm still only getting cold air! The coolant level is stable. For ref., the front of the car is still elevated - could the entry of coolant into the heater core be affected by the front being raised?

In total, I've put about 1.25G in, which is about the amount I got out.

Any thoughts?
 

·
Registered
Joined
·
85 Posts
I would first check the secondary waterpump, that pushes water to the heater core. Second, check the heater control valve under the leaf screen in front of the windshield.
 

·
Registered
Joined
·
2,224 Posts
Is your car is 190E 2.3 ? and do you have heat before this coolant flushed for new ? If you do :
#1- Take advise from RetroScott use your voltmeter see you have 12V at the plug or feel your pump running ( Heater control must be on)
#2- if it's 2.3 then check the cooling supply line ( or return) next to your oil filter area , this very soft line (3/4" rubber) maybe folding or bending some where at that location by accident it easy stop your hot water return from the heater core to engine..
Good luck my friend ..it's cold out side heh
 

·
Registered
Joined
·
115 Posts
Discussion Starter #5
Hi Folks,

Thanks for the ideas so far - let's work through them.

The engine is quite warm - too hot to touch for more than 1-2s, which leads me to believe the thermostat is not stuck open.

The car is a 190D. I did have tons of heat before the flush.

My line of testing will be:
1. Check 12V at the secondary waterpump with heater on.
2. Visually inspect heater control valve.

The other thing I read in the owner's manual last night was "on models fitted with an auxiliary heater, open bleed valve on the auxiliary heater". Does anyone know what this is? Is there is still air caught in there, that would also explain the symptoms.
 

·
Registered
Joined
·
1,757 Posts
On my 2.3, there is a bolt on the head at the front of the engine that you open when filling it with antifreeze. I also take off the small line return line that goes back to the coolant reservoir and elevate it while I'm filling, in addition to squeezing the upper and lower radiator hoses. I have found this works best for eliminating air in the system.
 

·
Registered
Joined
·
115 Posts
Discussion Starter #7
Solved the issue this evening. Short answer is that there was still air to be burped.

Longer answer:
After the initial fill, with the car on level, I couldn't get any 'burp'. Then I raised the car and got a fair bit of air out. However, no amount of running would get the remaining air out with the nose up. So I put the nose down, and promptly got the remaining air out of the heater circuit.

Thanks for the help guys, glad it wasn't anything more serious.
 

·
Registered
Joined
·
69 Posts
Did you jack the car up or park on a incline ? what else did you do? I have the same problem with heat and can't seem to get the air out.
 
1 - 9 of 9 Posts
Top