Losing Coolant
Thread Starter
Newbie
Joined: Dec 2019
Posts: 5
Likes: 3
From: Kuwait
ML63 2014
Losing Coolant
Hello,
I have the Top up coolant showing on the display for like every two or three days. Lately, there were so many leaks detected from the system. I found that leak came from the water pump, some leaks from the T houses and i changed them all then made a pressure test and it was good. But the system keeps losing coolant and i fill the tank for like every two days for 0.5Litera of coolant. Checked under the vehicle there were no drops. Also checked if there were leaks inside the engine there were not.
Anymore suggestions?
I have the Top up coolant showing on the display for like every two or three days. Lately, there were so many leaks detected from the system. I found that leak came from the water pump, some leaks from the T houses and i changed them all then made a pressure test and it was good. But the system keeps losing coolant and i fill the tank for like every two days for 0.5Litera of coolant. Checked under the vehicle there were no drops. Also checked if there were leaks inside the engine there were not.
Anymore suggestions?
Newbie
Joined: Dec 2019
Posts: 8
Likes: 2
ML63 W166 2014
Check to see if your oil is milk coloured and if there is any exhaust smell from the coolant reservoir. This would indicate a blown head gasket.
Also, try to smell the exhaust, if it smells sweet, then you are burning coolant.
Also, try to smell the exhaust, if it smells sweet, then you are burning coolant.
Out Of Control!!
Joined: Sep 2018
Posts: 14,694
Likes: 4,584
From: unbegrenzt
2017 GLE350 4MATIC
0.5 liters every two days is a significant consumption of coolant. I don't trust the pressure test that you said was done. There is an external leak (dripping somewhere), or internal leak (head gasket).
Drain 2 liters of coolant and look at it. Is transmission or engine oil in the coolant? As the above poster mentioned, is there coolant in the oil? Drain 2 liters of oil and look at it.
Drain 2 liters of coolant and look at it. Is transmission or engine oil in the coolant? As the above poster mentioned, is there coolant in the oil? Drain 2 liters of oil and look at it.
Thread Starter
Newbie
Joined: Dec 2019
Posts: 5
Likes: 3
From: Kuwait
ML63 2014
0.5 liters every two days is a significant consumption of coolant. I don't trust the pressure test that you said was done. There is an external leak (dripping somewhere), or internal leak (head gasket).
Drain 2 liters of coolant and look at it. Is transmission or engine oil in the coolant? As the above poster mentioned, is there coolant in the oil? Drain 2 liters of oil and look at it.
Drain 2 liters of coolant and look at it. Is transmission or engine oil in the coolant? As the above poster mentioned, is there coolant in the oil? Drain 2 liters of oil and look at it.
Out Of Control!!
Joined: Sep 2018
Posts: 14,694
Likes: 4,584
From: unbegrenzt
2017 GLE350 4MATIC
If coolant is escaping through the heating (HVAC) system, you would notice a smell inside the vehicle, or a drip outside of the vehicle. Do you notice a coolant smell inside the vehicle? What specification coolant are you using to top up with?
Thread Starter
Newbie
Joined: Dec 2019
Posts: 5
Likes: 3
From: Kuwait
ML63 2014
No there no smell inside the vehicle not even drips from outside. Im using the blue one from BMW. Do you recommend to use the red one from MB or doesn't matter?
Out Of Control!!
Joined: Sep 2018
Posts: 14,694
Likes: 4,584
From: unbegrenzt
2017 GLE350 4MATIC
Mercedes fluids are very specific. If it were my vehicle I would follow the manufacturer's specifications. I don't know if the BMW fluid is the same, or different, than the M-B fluid.
Start from the beginning:
- You are losing coolant
-- you drained the engine oil, and found no coolant
-- you drained the transmission oil, and found no coolant
-- you smell no coolant inside the vehicle
-- you have no drips under the vehicle
Where is the coolant going? You must have an idea by now. What do you think?
Start from the beginning:
- You are losing coolant
-- you drained the engine oil, and found no coolant
-- you drained the transmission oil, and found no coolant
-- you smell no coolant inside the vehicle
-- you have no drips under the vehicle
Where is the coolant going? You must have an idea by now. What do you think?
Last edited by chassis; Jan 19, 2020 at 04:02 PM.
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Thread Starter
Newbie
Joined: Dec 2019
Posts: 5
Likes: 3
From: Kuwait
ML63 2014
Mercedes fluids are very specific. If it were my vehicle I would follow the manufacturer's specifications. I don't know if the BMW fluid is the same, or different, than the M-B fluid.
Start from the beginning:
- You are losing coolant
-- you drained the engine oil, and found no coolant
-- you drained the transmission oil, and found no coolant
-- you smell no coolant inside the vehicle
-- you have no drips under the vehicle
Where is the coolant going? You must have an idea by now. What do you think?
Start from the beginning:
- You are losing coolant
-- you drained the engine oil, and found no coolant
-- you drained the transmission oil, and found no coolant
-- you smell no coolant inside the vehicle
-- you have no drips under the vehicle
Where is the coolant going? You must have an idea by now. What do you think?
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Out Of Control!!
Joined: Sep 2018
Posts: 14,694
Likes: 4,584
From: unbegrenzt
2017 GLE350 4MATIC
- coolant loss (you are experiencing this)
- coolant system pressure and leak down test
- cylinder compression and leak down test
- sweet smell from exhaust tailpipe
- white smoke or steam from exhaust tailpipe
- non-uniform spark plug coloration
- so-called "washed" pistons. This means the surface of the piston is clean and shiny, when viewed through the spark plug hole.
- coolant in engine oil or transmission oil
- rough idle, with or without a check engine light, and the rough idle may or may not go away when the engine is warm
- weeping or dripping of coolant or coolant+oil on the outside of the engine
If it were my vehicle, I would do each of these tests and note the result.
Thread Starter
Newbie
Joined: Dec 2019
Posts: 5
Likes: 3
From: Kuwait
ML63 2014
Yes, I agree. There are a number of tests to confirm if a head gasket is breached:
- coolant loss (you are experiencing this)
- coolant system pressure and leak down test
- cylinder compression and leak down test
- sweet smell from exhaust tailpipe
- white smoke or steam from exhaust tailpipe
- non-uniform spark plug coloration
- so-called "washed" pistons. This means the surface of the piston is clean and shiny, when viewed through the spark plug hole.
- coolant in engine oil or transmission oil
- rough idle, with or without a check engine light, and the rough idle may or may not go away when the engine is warm
- weeping or dripping of coolant or coolant+oil on the outside of the engine
If it were my vehicle, I would do each of these tests and note the result.
- coolant loss (you are experiencing this)
- coolant system pressure and leak down test
- cylinder compression and leak down test
- sweet smell from exhaust tailpipe
- white smoke or steam from exhaust tailpipe
- non-uniform spark plug coloration
- so-called "washed" pistons. This means the surface of the piston is clean and shiny, when viewed through the spark plug hole.
- coolant in engine oil or transmission oil
- rough idle, with or without a check engine light, and the rough idle may or may not go away when the engine is warm
- weeping or dripping of coolant or coolant+oil on the outside of the engine
If it were my vehicle, I would do each of these tests and note the result.
its been so long since I done the repairing and finally found the issue of the leaking. I did all the following tests and found no head gasket leaks. at last, it was leaking from the coolant tank it self from the bottom ://. the issue was from the cap, I was closing it so tight that's why the pressure aren't coming out from it, the pressure was leaking from somewhere else from the tank. the dealer said that when closing the cap it need to stop at the mark when it clicks. mine wasn't stopping at that it was going all the way until it tights. changed the cap and solved the problem.
Super Member
Joined: Aug 2004
Posts: 791
Likes: 37
From: Detroit Area
W203 C230, W210 E350, W166 ML63
its been so long since I done the repairing and finally found the issue of the leaking. I did all the following tests and found no head gasket leaks. at last, it was leaking from the coolant tank it self from the bottom ://. the issue was from the cap, I was closing it so tight that's why the pressure aren't coming out from it, the pressure was leaking from somewhere else from the tank. the dealer said that when closing the cap it need to stop at the mark when it clicks. mine wasn't stopping at that it was going all the way until it tights. changed the cap and solved the problem.
Newbie
Joined: Dec 2019
Posts: 8
Likes: 2
ML63 W166 2014
I had a similar problem with my ML63.
it would only lose coolant when warm, traced the problem to a small split in the radiator.
It was the left side right at the mounting point. It was difficult to spot, as it only happened when the car was warm and only left a small telltale marks near the ABS and coolant tank.
‘being a tight ****, I just mixed some epoxy and sealed it up. This fixed it for the past 9 months.
it would only lose coolant when warm, traced the problem to a small split in the radiator.
It was the left side right at the mounting point. It was difficult to spot, as it only happened when the car was warm and only left a small telltale marks near the ABS and coolant tank.
‘being a tight ****, I just mixed some epoxy and sealed it up. This fixed it for the past 9 months.
