CLK 63 AMG - Pre-Purchase Questions
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GL450 (2012) ; E320 Cabriolet (1995)
CLK 63 AMG - Pre-Purchase Questions
I am very interested in purchasing a CLK 63 AMG but am anxious to avoid some of the known problems.
Of particular concern are the headbolt and valve lifter problems with the M156 engine:
I understand that most early vehicles had these parts retrofitted under warranty, so I would just need to check service records to make sure that this was done. Is this a valid assumption?
I also understand that, from a certain point, MB started installing the new and improved parts such that they would not have been replaced - from what engine number (or other identifying number) did this occur?
I want to screen out cars that were fitted with the bad parts, and did not have them replaced.
I've also read about transmission problems in early vehicles - is this true and, if so, how do I screen out problems here (from what engine number onward was the problem resolved)?
Are there any other major defects that I should (and can) screen for when considering cars?
Thanks!
Of particular concern are the headbolt and valve lifter problems with the M156 engine:
I understand that most early vehicles had these parts retrofitted under warranty, so I would just need to check service records to make sure that this was done. Is this a valid assumption?
I also understand that, from a certain point, MB started installing the new and improved parts such that they would not have been replaced - from what engine number (or other identifying number) did this occur?
I want to screen out cars that were fitted with the bad parts, and did not have them replaced.
I've also read about transmission problems in early vehicles - is this true and, if so, how do I screen out problems here (from what engine number onward was the problem resolved)?
Are there any other major defects that I should (and can) screen for when considering cars?
Thanks!
Member
Joined: Nov 2013
Posts: 170
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2001 Clk55 AMG
The factory didn't change the parts until 2011 model year cars. Mercedes also didn't fix the early cars unless they failed. I would not assume the car was repaired. Most never have had a problem. Very few clk's have the m156 motor, so for motor specific questions you may have better luck asking in the c,e,s class forums.
Member
Joined: Jan 2007
Posts: 226
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From: Cape Cod
CLK63, E550, SL500 Silver Arrow,Corvette LT1,ZR1
None of the CLK 63 cars had the deadbolts replaced unless they failed while under warranty. I also read about a few owners that got some"goodwill" help from MBUSA and the dealer, however I doubt they would do that now as the last of the CLK 63's were 2008. I had all the deadbolts pre-emptively replaced on my car and it was just shy of $6,000.00. I told that is a deal versus what you pay if the engine fails or worst case hydro-locks! Good luck they are great cars and absolute beasts.
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Newbie
Joined: Aug 2016
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GL450 (2012) ; E320 Cabriolet (1995)
This is very helpful, albeit disappointing feedback, thank you! It appears I was given overly optimistic information regarding the extent to which these engine problems were addressed by MB.
In essence, any purchaser of a CLK 63 AMG at this point has two options:
Pay the purchase price, plus $6-8k to replace the headbolts and valve lifter which, left unattended, could result in catastrophic engine failure.
OR
Take your chances and hope that your car's parts are not defective; if you're lucky, great, if not you could face a repair bill that comes close to equaling the car's value.
Is there any indication that the problem doesn't occur past a certain mileage? E.g. if the headbolts or valve lifters are going to fail, they will have done so by 50k miles. I'm trying to stay optmistic :-)
I wonder if AMG keeps stats on this issue, and if they are willing to answer questions. I tried to find contact details online, but nada ... does anyone have an email address?
Thanks!
In essence, any purchaser of a CLK 63 AMG at this point has two options:
Pay the purchase price, plus $6-8k to replace the headbolts and valve lifter which, left unattended, could result in catastrophic engine failure.
OR
Take your chances and hope that your car's parts are not defective; if you're lucky, great, if not you could face a repair bill that comes close to equaling the car's value.
Is there any indication that the problem doesn't occur past a certain mileage? E.g. if the headbolts or valve lifters are going to fail, they will have done so by 50k miles. I'm trying to stay optmistic :-)
I wonder if AMG keeps stats on this issue, and if they are willing to answer questions. I tried to find contact details online, but nada ... does anyone have an email address?
Thanks!
Member
Joined: Jan 2007
Posts: 226
Likes: 3
From: Cape Cod
CLK63, E550, SL500 Silver Arrow,Corvette LT1,ZR1
You could check on the AMG Private lounge, but I doubt that information is floating around. The best bet for information is on the C class forum. There are a ton of differerent threads on the 156 engine issues/ concerns.
MBWorld Fanatic!
Joined: Nov 2009
Posts: 3,589
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From: Texas
C63 507 AMG DA Car #19
You might be able to pull a valve cover to see if the head bolts were replaced. From what i read here the bolt tops are different if replaced. Maybe they can run a borescope to see this?
MBWorld Fanatic!
Joined: Oct 2012
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From: Florida
2002 CLK 55 AMG cabriolet Eurocharged
There was a AMG resource engineer searching for failed head bolts in this forum a couple of years ago.
Some 6.3 engine owners have replaced them with ARP stud kits.
I believe it can be done on a strong healthy engine one at a time in sequence without disturbing the head gasket. (theory)
Studs have superior clamping abilities as opposed to cap screw bolts. Most all race engines are prepped with studs.
I would collect all warranty information before modifying though.
2 cents, Gator
Some 6.3 engine owners have replaced them with ARP stud kits.
I believe it can be done on a strong healthy engine one at a time in sequence without disturbing the head gasket. (theory)
Studs have superior clamping abilities as opposed to cap screw bolts. Most all race engines are prepped with studs.
I would collect all warranty information before modifying though.
2 cents, Gator
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From: Carrollton Texas
clk and e coupe
There was a AMG resource engineer searching for failed head bolts in this forum a couple of years ago.
Some 6.3 engine owners have replaced them with ARP stud kits.
I believe it can be done on a strong healthy engine one at a time in sequence without disturbing the head gasket. (theory)
Studs have superior clamping abilities as opposed to cap screw bolts. Most all race engines are prepped with studs.
I would collect all warranty information before modifying though.
2 cents, Gator
Some 6.3 engine owners have replaced them with ARP stud kits.
I believe it can be done on a strong healthy engine one at a time in sequence without disturbing the head gasket. (theory)
Studs have superior clamping abilities as opposed to cap screw bolts. Most all race engines are prepped with studs.
I would collect all warranty information before modifying though.
2 cents, Gator
The head bolts were an issue but it isnt as common as some people make it out to be.
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MBWorld Fanatic!
Joined: Feb 2002
Posts: 1,311
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From: Manchester, CT
At this point in time and the car's ages.....if it ain't broken yet don't worry about it. Just my 2 cents. Only a very small numbers of engines thru certain numbers (AMG lounge has/had the affected engine numbers) actually had bolt failures. If you got the cash and want to be pro-active the APR head studs are the way to go. I know of a few local MB mechanics who off-duty have the done the head bolts (new factory upgraded ones) for 2500$....I was concerned too when I bought my 63, but 4 years later I can say that the concern was not warranted.And from the few other M156 owners I know who HAD the bolt problems it was because they tracked/beat on their cars...which is really what AMG intends, yes?
