Question for M156 owners (potential newbie here)

[dannyfiveforty]

good morning, I have already done some extensive research all thanks to a youtuber highlighting design flaws to the M156 specifically the head bolts.

I am considering purchasing a CL this summer (I haven’t found the car yet) but these horror stories are putting me off. I have spoken to MSL in Birmingham (remapped my 350cdi) and they quoted £3,000 to replace the head bolts, they advised to not bother replacing them until one fails.

Trouble is, how will I tell if a potential car am viewing has a failed bolt/bolts? Is it a major concern or has it been hyped?

What are fellow M156 thoughts?

Thanks, Daniel

 

[daveenty]

For every one which you hear about failing, there are many thousands which haven't and are still running fine.

There's no hard and fast rule to find out if they've been done or not, unless the owner is in possession of a genuine receipt. I would however be tempted to look at the M157 Bi Turbo, especially in a CL as it would suit it a lot better...

 

[John Laidlaw]

As Daveenty says, loads never had an issue at all but engine numbers 60658 onwards should be clear
I’d also endorse the later Bi- Turbo, much more flexible and MSL will remap beautifully should you need a bit more power!

 

[Rotorhead500]

As above, with a CL, nice lazy bi-turbo torque available for superior waftage.

Failing that, and I don't know if it was ever an option on the CL M156, but if there was an AMG Performance Pack, then that had the SLS head bolts fitted anyway, so problem avoided!

 

[alexanderfoti]

You can check engine numbers affected, but by now, most of them will have been giving symptoms

also +1 for bi-turbo in the 216

 

[GordonTarling]

So, what symptoms could be expected if one bolt failed? Similar to those seen with a failed head gasket?

 

[AMGeed]

So, what symptoms could be expected if one bolt failed? Similar to those seen with a failed head gasket?

Coolant low warning is usually the first indication all is not well I have read.

 

[GordonTarling]

Thanks.

 

[mbzclk]

Go for the Bi Turbo!!

 

[gstar888]

As above, with a CL, nice lazy bi-turbo torque available for superior waftage.

Failing that, and I don't know if it was ever an option on the CL M156, but if there was an AMG Performance Pack, then that had the SLS head bolts fitted anyway, so problem avoided!

Question about performance package on M156 engines. I have an ‘08 S63 with factory P1,P2,P3 packages. My VIN also fits within the problem head bolt number range.
This post is the first I’ve heard about performance packages having SLS head bolts. If this is true, it would take a huge burden out of the back of my head every time I go on a decent road trip.
Anyone know how to confirm this?
Car is from the states. Has 115k miles on it now but I have never had heat problems in the last 50k miles outside of a radiator crack.
LOVE this forum!


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[Rotorhead500]

Question about performance package on M156 engines. I have an ‘08 S63 with factory P1,P2,P3 packages. My VIN also fits within the problem head bolt number range.
This post is the first I’ve heard about performance packages having SLS head bolts. If this is true, it would take a huge burden out of the back of my head every time I go on a decent road trip.
Anyone know how to confirm this?
Car is from the states. Has 115k miles on it now but I have never had heat problems in the last 50k miles outside of a radiator crack.
LOVE this forum!


Sent from my iPhone using Tapatalk

I'm sure one of the Indie's on here can probably clarify... But maybe an email to MBUK is also worth a punt?

 

[alexanderfoti]

Question about performance package on M156 engines. I have an ‘08 S63 with factory P1,P2,P3 packages. My VIN also fits within the problem head bolt number range.
This post is the first I’ve heard about performance packages having SLS head bolts. If this is true, it would take a huge burden out of the back of my head every time I go on a decent road trip.
Anyone know how to confirm this?
Car is from the states. Has 115k miles on it now but I have never had heat problems in the last 50k miles outside of a radiator crack.
LOVE this forum!


Sent from my iPhone using Tapatalk

lifter buckets wont fail overnight, so I wouldn't be concerned with them on a long road trip. Far more likely to have issues elsehwere (tyres etc!)

 

[gstar888]

I'm sure one of the Indie's on here can probably clarify... But maybe an email to MBUK is also worth a punt?

Thanks for the suggestion Rotorhead500, I’ll shoot out a note to MBUK with some of my VIN details.
Now that I know this might have been a head bolt option, I’ll keep poking around for more info.


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[Rotorhead500]

Thanks for the suggestion Rotorhead500, I’ll shoot out a note to MBUK with some of my VIN details.
Now that I know this might have been a head bolt option, I’ll keep poking around for more info.


Sent from my iPhone using Tapatalk

No worries - my reference has been a W204 era C63... so knowing that engine was used across various platforms, you may be ok... [crosses fingers]

 

[alexanderfoti]

To add, the PP engines do have SLS buckets.

 

[Amin white c63]

Hi all. New here

I purchased a c63 w204 and 2 months down the line it broke down.
Mercedes Stratford suspect it's a gasket failure and I beleive it's all down to the headbolts. I had leaking coolant prior to breakdown.

Mb stratford wont give me an official quote as they need to strip down the engine in order to officially diagnose it which could apparently run into 10hours labour or £2k before I could find out what's exactly wrong!

I've got mb warranty on the car but I'm not willing to gamble £2k before finding out how much the full repair will cost. Also gaskets isnt covered under warranty but I beleive the bolts are (if anyone can confirm?)

Daniel, was the £3k quote from MSL including parts and labour? And were they arp bolts or oem standard ones?
Thanks

 

[AMGeed]

Daniel, was the £3k quote from MSL including parts and labour? And were they arp bolts or oem standard ones?
Thanks

Sorry to hear of your engine woes. If you have a Mercedes warranty, the head bolt should be covered.
If the dealer suspects head gasket failure, he will have to strip out the head bolts anyway. Dig your heels in. This needs to be acknowledged its warranty work.
I believe a few years back MSL used ARP studs to replace the OEM bolts,but a new design is now used.
Almost sure the cost quoted was parts & Labour.
Have a chat with Acid about your problem and get his opinion. He has seen this this occur more than once.
0121 772 5572

 

[Amin white c63]

Sorry to hear of your engine woes. If you have a Mercedes warranty, the head bolt should be covered.
If the dealer suspects head gasket failure, he will have to strip out the head bolts anyway. Dig your heels in. This needs to be acknowledged its warranty work.
I believe a few years back MSL used ARP studs to replace the OEM bolts,but a new design is now used.
Almost sure the cost quoted was parts & Labour.
Have a chat with Acid about your problem and get his opinion. He has seen this this occur more than once.
0121 772 5572

Hey thanks for such a quick response. Will give Acid a call tomorrow and have a chat. I think I'll also be popping over to mercedes soon and demand to sit down properly and iron out what exactly they'll cover / not cover. And the costs of those parts that are not covered. I have a feeling they didnt want to do the job and did their best to scare me off with the costs.

 

[Rotorhead500]

Remind them that it is also a well recognised issue on that engine, of that age... quite well documented.

 

[alexanderfoti]

yes I agree, put pressure on them.