M156 - pre 2011 - how risky?

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6cyl

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I've been looking at C63/E63 with the M156 V8. It has a few inherent design issues, such as head bolts that rust causing head gasket failures or leaking of coolant.
There are also issue with the hydraulic tappets too.

How common are these problems? Would you get the bolts replaced or just take the risk? Do you get the opportunity to detect and mitigate or is it a sudden and catastrophic failure?

The 5.5 TT have other issues?
 
I've been looking at C63/E63 with the M156 V8. It has a few inherent design issues, such as head bolts that rust causing head gasket failures or leaking of coolant.
There are also issue with the hydraulic tappets too.

How common are these problems? Would you get the bolts replaced or just take the risk? Do you get the opportunity to detect and mitigate or is it a sudden and catastrophic failure?

The 5.5 TT have other issues?
I wouldn't do it unless the head bolts have been done with receipts.

I mean the stress of worrying about the issues would kill the experience and enjoyment of owning it unless the issues have been addressed. Try get a facelifted (204) C63 man.
 
Head bolts are a low risk on the 156....and in my opinion it's blown out of all proportion and there are thousands of these on the road with original bolts. Even when they are changed as a precaution they are most times fine with no serious corrosion. If they have not failed by now, over ten years later, you are probably ok. That said....unless the noise is the be all and end all for you the 157 is a better engine in every measurable way....IMO! And the E63 with the 157 (in facelift or pre facelift) can be had for similar money to the later 156 engined ones. Not the case with the C63 205 of course which never had the 157. Just check it has the later cam chain (easily checked through the oil filler cap) and oil control valve.
 
Buy a relatively expensive car which has had the pre-emptive maintenance done (with receipts!) or buy a relatively inexpensive car and budget to have it done. Either way you’ll buy a car with peace of mind on these issues and the added confidence that it’s been looked after.

Don’t buy a “good value” example which hasn’t had top end done and expect it to be perfect for as long as you own it. What @ALFAitalia suggests is true, the headbolts aren’t as common as the Internet rumours suggest. Lifter buckets will be showing signs of wear by 100-110k miles though, and the cam adjuster plates will be worn too.

Therefore if you can, buy a car with well below 100k miles - or well above 110k miles - so top end work is either not due or has already been done. If you do buy a car with say 80-130k miles (without top-end work already done) pay a price according to the risk and keep a healthy maintenance and emergency fund.

They’re worth it.
 
PS Regarding M156 or M157, both have their commonly reported issues. The M156’s issues are the most reported on the Internet though. Both are wonderful engines, but are wonderful in different ways.

If it’s your main car that you use for everything then I’d say the M157 is a better proposition. If it’s an occasional car, then the M156 edges it. If you are into tuning then the M157 will reward you with easy gains. If naturally aspirated engines are your thing the the M156 will be your bag.

The M157 is a great engine, however the M156 will be remembered as one of the greatest. Not because it’s better when driving from Corby to Daventry in rush hour traffic, but because it’s a bit spesh in lots of ways. I would say it’s the closest engine to being the working man’s Porsche 980/01.

PPS M157 is better for that Daventry dash.
 
Hi Bobby Dazzler :

As a matter of interest what premium should a buyer be prepared to pay for a good example car
 
^^^ X2, summed up perfectly

The headbolts are low risk, antifreeze that we use contain anti corrosion inhibitors that prevent corrosion, summer coolant. There are 3 types of headbolts, earlier ones were T55 found from years approx 06 to 08, then from around 08 to 10 they switched to T60 head bolts which had slightly less material and then they made a final switch to E14 headbolts which were the supercedes ones with more material. There are specific engine cut off numbers, I have the number saved somewhere?

M156 is very thirsty and ferroucious. M157 is very refined, better on economy and much much faster. The m156 shares some common linearage to Porsche M80 V10 race engine, headed by Bernd Rambler who worked previously for Mercedes and Porsche. It's the first engine built ground up by AMG.

Both are wonderful engines and both have some weaknesses in design 🙂👍
 
Hi Bobby Dazzler :

As a matter of interest what premium should a buyer be prepared to pay for a good example car
It really depends on the car, the mileage, the work done, who did it, etc.

A properly maintained car - with all preventative maintenance all completed, and all wear items in good order - could easily have had £10-15k spent on it recently.

For that reason, paying £5k more than an otherwise identical car would be a bargain as long as there are genuine receipts from a credible garage with a good reputation.

Even at £7.5k on top it could still be good value especially if the tyres, brakes and other wear items are up to scratch. Few buyers will be prepared to pay more than the cheapest though.
 
Hi , thank you for your swift reply.

I have spent in the region of £5000 on servicing my C207 and if I traded my car in today it worth in the region of £12000.

The car now has 49000 miles on the clock so a reasonable mileage for a 65 plate car.

From my understand what you said people want a top notch car for banger money.

Not a great reason to service cars is it !
 
Out of curiosity how much would it cost someone to get the headbolts and tapets changed and the other bits in one hit.
 
Out of curiosity how much would it cost someone to get the headbolts and tapets changed and the other bits in one hit.
It depends on where you source the parts, what else is found whilst the work is in progress, and who does the work. Labour will vary most.

If any of the buckets are worn then it may cause some wear to the corresponding cam lobes, so the affected cam(s) may need to be replaced.

Similarly one or more of the variable valve timing units will likely require attention, so either replacements or repair kits may be required too.

If paying someone else to do the work then expect £5-15k depending upon how much of that lot needs to be done and who does the work for you.m

That’s a broad range however if you’re going to incur the labour cost to do the head bolts and buckets you might as well do whatever needs doing.
 
These questions pop up every now and again. How reliable is the Mighty M156.

The mighty M156 Is as reliable as any other poxy mercedes engines out there. It's also the only engine built in house at AMG. "Unsure" if this is still the case as don't look into to much of the newer stuff it's not my bag.

This headbolt, cam adjuster wear and god knows what else is blown way out of proportion. It's mentioned like it's open heart surgery like an every day accurance. IT ISN'T, LETS GET THAT STRAIGHT, moving on 😀

Regular engine oil changes and coolant changes prolong any engine but the M156 does love an oil change. Why not, it's that special it deserves them. Keeps it sounding so good. Ready for the next launch 🚀

I have owned mercedes variants that have caused me much more financial hassle than the so called problomatic M156. Won't name them as that will open up another mothers meeting nag nag nag.

Owned mine now coming up 5 years. It's been a delight and I intend keeping it as long as I possibly can. It's not new technology but it sure packs a punch and if you can Tel me a better sounding than engine and exhaust note them I'm yet to hear it!

Hope your all keeping well MB people, M156 Tom, over and out 😀👍
 
I wouldn't do it unless the head bolts have been done with receipts.

I mean the stress of worrying about the issues would kill the experience and enjoyment of owning it unless the issues have been addressed. Try get a facelifted (204) C63 man.
Very low risk worry about it if/when it occurs.
 
The mighty M156 Is as reliable as any other poxy mercedes engine out there.
It's not. The M113 in all its versions beats it, and the even more mighty M157, hands down for reliability.

That said, though, the M113 is an exceptionally strong engine, even tuned versions. Just ask MSL.

I've had lots of them, from 300 to 480 bhp, with mostly over 100K miles on them, and had no problem with any of them.

To be fair, though, none of those engines is unreliable; quite surprising, really, when you consider that all of them in their day were making very high power outputs for the time. Neither the 113K, the 156 nor the 157 will disappoint.
 
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These questions pop up every now and again. How reliable is the Mighty M156.

The mighty M156 Is as reliable as any other poxy mercedes engines out there. It's also the only engine built in house at AMG. "Unsure" if this is still the case as don't look into to much of the newer stuff it's not my bag.

This headbolt, cam adjuster wear and god knows what else is blown way out of proportion. It's mentioned like it's open heart surgery like an every day accurance. IT ISN'T, LETS GET THAT STRAIGHT, moving on 😀

Regular engine oil changes and coolant changes prolong any engine but the M156 does love an oil change. Why not, it's that special it deserves them. Keeps it sounding so good. Ready for the next launch 🚀

I have owned mercedes variants that have caused me much more financial hassle than the so called problomatic M156. Won't name them as that will open up another mothers meeting nag nag nag.

Owned mine now coming up 5 years. It's been a delight and I intend keeping it as long as I possibly can. It's not new technology but it sure packs a punch and if you can Tel me a better sounding than engine and exhaust note them I'm yet to hear it!

Hope your all keeping well MB people, M156 Tom, over and out 😀👍

Was wondering where my M156 good friend had gone to? Welcome back 😃👍
 
Was wondering where my M156 good friend had gone to? Welcome back 😃👍

Nice one badgx 😀👍up the Mighty 156 🏆
 

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