Coolant missing and can't be found
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2009 CLS63, 2008 ML63, 2011 Camaro 6.2
Coolant missing and can't be found
Hello folks,
I bought a used car 2009 with the 6.2 liter M156 engine and 49,000 miles on the dash recently.
The car keeps asking me for coolant. It loses sometimes more, sometimes less but approximately half a gallon on 120 miles. When I topped it up first I thought it was usual consumption. But when it needed more I knew something was off.
I had the car already at multiple mechanics which tried to look for the usual suspects like, hoses, waterpump, radiator, thermostat. Nothing, the car also never has any puddles or viewable drips. They also checked the heating / cooling system which works fine and does not leak.
Despite the car produces no smoke and the oil and coolant caps look normal we performed a chemical test for the head gasket which came back without problems.
Any other suggestions?
Thanks
Mik
I bought a used car 2009 with the 6.2 liter M156 engine and 49,000 miles on the dash recently.
The car keeps asking me for coolant. It loses sometimes more, sometimes less but approximately half a gallon on 120 miles. When I topped it up first I thought it was usual consumption. But when it needed more I knew something was off.
I had the car already at multiple mechanics which tried to look for the usual suspects like, hoses, waterpump, radiator, thermostat. Nothing, the car also never has any puddles or viewable drips. They also checked the heating / cooling system which works fine and does not leak.
Despite the car produces no smoke and the oil and coolant caps look normal we performed a chemical test for the head gasket which came back without problems.
Any other suggestions?
Thanks
Mik
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12 C63BS Magno Alanite Grey, 25 X5 Msport, 08 BMW E93, Ducati Hyper 698
I would immediately stop driving it and search head bolt issues on here, it is likely one or more headbolts have failed as it is a known issue on pre 2011 m156 engines they corrode and the bolt heads pop off, if it is just one or 2, you will get a small leak into combustion, not enough to really notice at the tailpipe but a slow reduction in coolant like you have will be noticed. They may not even leak at all when sitting but leak a little when warmed up. You will likely need to replace the headbolts with the updated style and if they have already failed you likely need to remove the heads to get the broken ones out - a lot of people replace them one bolt at a time before they fail but one one fails not sure if there is any way to get it out without pulling the heads. Sorry for the bad news but don't drive it would be my heavy advice as it can eventually destroy an engine. Start with a pressure test and an exhaust gas test of the cooling system. That much coolant without a puddle is being burned likely and with the known issue of headbolts failing that model year it is highly likely that is the issue.
Last edited by roadkillrob; Jul 11, 2022 at 06:55 PM.
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2008 E350 4MATIC, 1985 300TD, 2009 ML63 AMG
I was having the exact same symptoms as you and decided to change the head bolts and head gaskets. While disassembling, I found a snapped head bolt on cylinder 5 by the driver's side, with the top of the bolt just rolling around the head... Before disassembly: Coolant pressure was holding, I was not getting white smoke out of the exhaust, pistons were dry on borescope examination, and my oil and coolant were not mixing. Unfortunately, this head bolt issue presents insidiously. I hope the same has not happened to you.
Thread Starter
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2009 CLS63, 2008 ML63, 2011 Camaro 6.2
Thanks guys. I will bring it in tomorrow to check the screws.
do I need to replace the head gasket too or is this optional ?
I see the replacement screws are made by Elring. How many of those will I need to replace them all?
Thanks
do I need to replace the head gasket too or is this optional ?
I see the replacement screws are made by Elring. How many of those will I need to replace them all?
Thanks
Junior Member
Joined: Feb 2020
Posts: 16
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2008 E350 4MATIC, 1985 300TD, 2009 ML63 AMG
20 head bolts, and yes if the head gasket is compromised you must replace the head gasket, it cannot be re-crushed. Along with the bolts and head gaskets, it is recommended to change the camshaft adjuster bolts and camshaft bearing bolts as well. You must remove the intake manifold, so you will need to replace the 10 intake manifold bolts due to being made of aluminum and are one-time use and the 2 intake manifold gaskets. You also need new valve cover gaskets. Depending on how the job is done as some remove the exhaust manifold from the head, you will need new exhaust manifold gaskets and probably new exhaust nuts and studs. There are certainly more parts to go over but I think those are the main ones? Are you tackling this job alone? Otherwise, just have an experienced M156 mechanic handle everything, assuming you have $$$$$, then no need to worry about all the parts.
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2009 CLS63, 2008 ML63, 2011 Camaro 6.2
Thanks, your help is very much appreciated. Great input !
I will discuss with my mechanic tomorrow.
Just ran the parts list and thats already 550 plus new oil. Sucks ***...
I will discuss with my mechanic tomorrow.
Just ran the parts list and thats already 550 plus new oil. Sucks ***...
Last edited by mikxx; Jul 11, 2022 at 09:00 PM.
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12 C63BS Magno Alanite Grey, 25 X5 Msport, 08 BMW E93, Ducati Hyper 698
While you are in there stuff do the pcv as it is cheap and they fail often and are easy when I take is off. Inspect lifters but a good time to replace with updated ones put is 600 or so for them. Injectors are about 250 a set and 50k miles is a good time to change them before they leak and hydro lock the engine. Last but not least since cam adjusters are out if you have startup rattle might be time to rebuild the plate which is like 800 ish for parts.
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AMG C63
Cams (possibly), lifters(absolutely), injectors (may as well, you're clocking 50k and the injectors maybe have another 15-20k of life left), and motor mounts (these always need to be repaired and you're just buying time and saving on labor doing it now) just to start.
Last edited by GarlicBread; Jul 12, 2022 at 10:48 AM. Reason: Nuance
Thread Starter
Junior Member
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2009 CLS63, 2008 ML63, 2011 Camaro 6.2
While you are in there stuff do the pcv as it is cheap and they fail often and are easy when I take is off. Inspect lifters but a good time to replace with updated ones put is 600 or so for them. Injectors are about 250 a set and 50k miles is a good time to change them before they leak and hydro lock the engine. Last but not least since cam adjusters are out if you have startup rattle might be time to rebuild the plate which is like 800 ish for parts.
Thread Starter
Junior Member
Joined: Feb 2022
Posts: 25
Likes: 0
2009 CLS63, 2008 ML63, 2011 Camaro 6.2
Thread Starter
Junior Member
Joined: Feb 2022
Posts: 25
Likes: 0
2009 CLS63, 2008 ML63, 2011 Camaro 6.2
Junior Member
Joined: Feb 2020
Posts: 16
Likes: 5
2008 E350 4MATIC, 1985 300TD, 2009 ML63 AMG
A specialist near me with stellar reviews quoted $4500 for head gasket replacement labor, parts NOT included! They said that if a head bolt is broken, they would charge even more.
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12 C63BS Magno Alanite Grey, 25 X5 Msport, 08 BMW E93, Ducati Hyper 698
MBWorld Fanatic!
Joined: Aug 2016
Posts: 2,405
Likes: 724
12 C63BS Magno Alanite Grey, 25 X5 Msport, 08 BMW E93, Ducati Hyper 698
Member
Joined: Jun 2020
Posts: 208
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AMG C63
There is no shame in admitting you're above your paygrade.
Plenty of people pay other people to do work on their cars. Especially this kind of work.
The world of nuance you're about to enter is incredibly unforgiving.
The wrong decision would be making an ego save attempt and not biting the bullet and eating it.
Everyone gets screwed on cars no matter what so don't take it personally.
If you can't find someone to do the work, your best bet is to cut your losses where they are, sell/trade the car and inform the person you're dealing with what you found.
Plenty of people pay other people to do work on their cars. Especially this kind of work.
The world of nuance you're about to enter is incredibly unforgiving.
The wrong decision would be making an ego save attempt and not biting the bullet and eating it.
Everyone gets screwed on cars no matter what so don't take it personally.
If you can't find someone to do the work, your best bet is to cut your losses where they are, sell/trade the car and inform the person you're dealing with what you found.
