ML250 Consuming Antifreeze - where to start?
Thread Starter
Member
Joined: Apr 2007
Posts: 97
Likes: 1
From: Doylestown (Bucks County) PA
2015 ML250, 06 E320 CDI, 2008 GL320 (sold)
ML250 Consuming Antifreeze - where to start?
My ML250 w 75K is consuming antifreeze. Low level warning goes on, top it off and its low again after 500 miles or so. Its not leaking anywhere that I can see. Thanks....
Assuming head gasket but thought I would ask. Need to find an indie in my area....Doylestown PA, 30 miles north of Philly.
Assuming head gasket but thought I would ask. Need to find an indie in my area....Doylestown PA, 30 miles north of Philly.
Out Of Control!!
Joined: Sep 2018
Posts: 14,694
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From: unbegrenzt
2017 GLE350 4MATIC
Yes.
Coolant consumption can either be internal or external.
Extrernal can be confirmed or denied by careful underhood inspection with a bright LED light. Check engine block sides and front for signs of coolant leaks and drips. Do you have drips under the car? Check radiator for cracks and leaking hoses and fittings.
Internal can be confirmed by rough idle, misfire with or without CEL, steam from tailpipe, sweet smell from tailpipe, “washed” top of piston or spark plug, or low compression.
Coolant consumption can either be internal or external.
Extrernal can be confirmed or denied by careful underhood inspection with a bright LED light. Check engine block sides and front for signs of coolant leaks and drips. Do you have drips under the car? Check radiator for cracks and leaking hoses and fittings.
Internal can be confirmed by rough idle, misfire with or without CEL, steam from tailpipe, sweet smell from tailpipe, “washed” top of piston or spark plug, or low compression.
Super Member
Joined: Jun 2022
Posts: 739
Likes: 328
From: WA State, USA
2014 Cummins, 2014 E250 Bluetec
Yes.
Coolant consumption can either be internal or external.
Extrernal can be confirmed or denied by careful underhood inspection with a bright LED light. Check engine block sides and front for signs of coolant leaks and drips. Do you have drips under the car? Check radiator for cracks and leaking hoses and fittings.
Internal can be confirmed by rough idle, misfire with or without CEL, steam from tailpipe, sweet smell from tailpipe, “washed” top of piston or spark plug, or low compression.
Coolant consumption can either be internal or external.
Extrernal can be confirmed or denied by careful underhood inspection with a bright LED light. Check engine block sides and front for signs of coolant leaks and drips. Do you have drips under the car? Check radiator for cracks and leaking hoses and fittings.
Internal can be confirmed by rough idle, misfire with or without CEL, steam from tailpipe, sweet smell from tailpipe, “washed” top of piston or spark plug, or low compression.
OP, check your engine bay when its hot after long run, stop pop hood and take look around with flashlight. If its external it may only display then. Otherwise check you fluids and have your oil tested. Could be egr cooler as well.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,225
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From: V E G A S
1922 Ford Model T / no OBD
Water pumps have small drain hole at the bottom, who is not visible from the outside.
Small leak will run down the hole and vaporize before reaching engine bottom. Only when the leak become bigger, you will notice coolant dripping.
Get a mirror, or snake camera and look at the bottom of the pump for caked coolant residues.
Small leak will run down the hole and vaporize before reaching engine bottom. Only when the leak become bigger, you will notice coolant dripping.
Get a mirror, or snake camera and look at the bottom of the pump for caked coolant residues.
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Thread Starter
Member
Joined: Apr 2007
Posts: 97
Likes: 1
From: Doylestown (Bucks County) PA
2015 ML250, 06 E320 CDI, 2008 GL320 (sold)
no rough idle and no antifreeze smell from exhaust....yet. Don't have access to car until late next week and will dive in. I have not checked oil to see if any water instrusion.
Super Member
Joined: Jun 2022
Posts: 739
Likes: 328
From: WA State, USA
2014 Cummins, 2014 E250 Bluetec
Remember your exhaust does a really good job of removing things, one of those is smell of stuff that has burned up in the engine and the exhaust. It will not be a good indicator of any type of leak that results in a noticable exhaust change more than likely. You could have a head gasket leak or valve seal leak and never know it if the exhaust is intact and functioning properly.
Thread Starter
Member
Joined: Apr 2007
Posts: 97
Likes: 1
From: Doylestown (Bucks County) PA
2015 ML250, 06 E320 CDI, 2008 GL320 (sold)
Remember your exhaust does a really good job of removing things, one of those is smell of stuff that has burned up in the engine and the exhaust. It will not be a good indicator of any type of leak that results in a noticable exhaust change more than likely. You could have a head gasket leak or valve seal leak and never know it if the exhaust is intact and functioning properly.
MBWorld Fanatic!
Joined: Jan 2009
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From: V E G A S
1922 Ford Model T / no OBD
On OM654 the oil cooler seals cost $7, when whole new cooler about $170. It is labor to get there what makes job expensive if you don't DIY.
OM651 has oil cooler easy accessible. My 2 cars with this engine, both having over 100k miles don't leak. (knock on the wood)
OM651 has oil cooler easy accessible. My 2 cars with this engine, both having over 100k miles don't leak. (knock on the wood)
Super Member
Joined: Jun 2022
Posts: 739
Likes: 328
From: WA State, USA
2014 Cummins, 2014 E250 Bluetec
How common is a head gasket leak on ML250 without a causing event? I had a GL350 (2008) that had a leak develop in the cooler that was located in the V of the block. That was an expensive repair and very common from what I understand on the alum block 320 diesel. Hoping this motor does not have that cooler issue and we are looking for a water pump leak. Makes the most sense (if I'm lucky).
I will say that most in my experience head gasket issues is either replacing the heads on diesels (things can go wrong from time to time), for some reason the engine overheats (lost coolant usually), or the MOST common is a bad tune when they delete there diesels. The quickest and easiest way to blow a head gasket imho. My overall experience is not with MB diesels however so .....
Senior Member
Joined: Jan 2010
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1997 E300D
I have a '97 NA 606 that has had a coolant leak from the head gasket for many years. I keep it under control with radiator sealant. I understand that coolant leaks from the head gasket are fairly common on my vintage of diesel straight six. I have seen a fair number on the forums.
Thread Starter
Member
Joined: Apr 2007
Posts: 97
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From: Doylestown (Bucks County) PA
2015 ML250, 06 E320 CDI, 2008 GL320 (sold)
I inspected the water pump and there is no visable leak after driving/heat up. I did look when cold too and no leak. Looking in the overflow tank and it has a foamy appearance on the top after driving. There is no water or antifreeze in the engine oil. So much for an easy fix (water pump).
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,225
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From: V E G A S
1922 Ford Model T / no OBD
Can you take a picture of the foam in reservoir?
Usually with HG leak you will have oil film on top of the coolant, but possible that small leak is not going that fair.
I remember test kits available, who will test the coolant for exhaust gases and oil
Usually with HG leak you will have oil film on top of the coolant, but possible that small leak is not going that fair.
I remember test kits available, who will test the coolant for exhaust gases and oil
Thread Starter
Member
Joined: Apr 2007
Posts: 97
Likes: 1
From: Doylestown (Bucks County) PA
2015 ML250, 06 E320 CDI, 2008 GL320 (sold)
Just spoke to my indie shop and there is a TSB on the engine oil cooler. TSB speaks to replacing the heat exchanger and all the associated tubing.
