M156 enquiries

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BuickUS4
Senior
Posts: 58
Joined: Thu Feb 24, 2022 4:35 pm

Greetings everyone, I apologise for revisiting several questions about the M156. I am seeking guidance and have been unable to locate precise responses.

Do the head bolts on a 2012 C63 provide improved quality and hence a reduced danger compared to older M156 models? I understand that the concept of danger may be exaggerated, but I am just interested in obtaining this information.

Furthermore, how can an inexperienced individual such as myself detect any problems pertaining to lifter buckets and cam adjustment plates, assuming they exist at all?!?

The car has had 14 MB services, so there is no need for excessive concern. Despite having travelled more than 90,000 kilometres.

Expressing gratitude!
Martin_Smith76
Senior
Posts: 86
Joined: Wed Nov 11, 2020 9:40 pm

"One of the primary problems that persist in all M156 models is the malfunction of the crankcase breather valve." The primary problem encountered with the breather valve is the gradual degradation of the diaphragm over a period of time. Another problem associated with the breather valve is the degradation and cracking of the hose connecting the crankcase to the valve. These problems might result in excessive oil consumption, emission of thick smoke from the exhaust pipes, and engine misfires. Additional prevalent concerns include early degradation of engine lifters and camshafts, as well as malfunctioning cam shaft adjusters. Typical indications of this issue include the presence of a ticking sound when the vehicle is started in chilly conditions. Additional prevalent problems include intake manifold failure, head bolt troubles in vehicles manufactured between 2007 and 2011, and drive belt pulley malfunctions.

According to Wikipedia, this information may not be required or factual. Approximately 9 minutes into the second video, the presenter demonstrates the visibility of the head bolts after removing the valve cover. In the first video, Alex demonstrates the use of black series cam buckets, which possess a distinct hue compared to the original ones.

I would expect that a 2012 model will be equipped with the latest headbolts. Verification may be conducted using the engine number. Interestingly, in the second video, he suggests that the headbolt failures occurred in engines with lesser mileage and those with extremely high mileage. Therefore, if they have not used a typical motor vehicle, they should be in a satisfactory condition.

In my humble opinion, it is something of a gamble.
BuickUS4
Senior
Posts: 58
Joined: Thu Feb 24, 2022 4:35 pm

Thank you for your excellent response.
Martin_Smith76
Senior
Posts: 86
Joined: Wed Nov 11, 2020 9:40 pm

I have made a revision. The video lasts a few minutes and shows the head bolts, which are visible when the cam cover is removed. Uncertain whether any prospective seller would let someone to remove the valve cover for a brief inspection.

Are you enquiring about workshop invoices and photographs?
BuickUS4
Senior
Posts: 58
Joined: Thu Feb 24, 2022 4:35 pm

Thank you, Martin_Smith76. There is no documentation of any engine maintenance. Therefore, I will make it a priority to inspect the engine as soon as possible and carefully listen for any signs of engine malfunction.
BuickUS4
Senior
Posts: 58
Joined: Thu Feb 24, 2022 4:35 pm

Unfortunately, after completing my YouTube training on identifying faulty cam adjusters by sound, I have determined that the vehicle in question does indeed have this issue. Therefore, I cannot proceed with purchasing the car.

Does it cost around £3,000 to resolve?V
mortimerPAS
Senior
Posts: 92
Joined: Sun Sep 15, 2019 8:45 pm

Based on my little investigation, it seems that the majority of engine problems are related to the upper portion of the engine. Issues such as cam lobe wear, lifter problems, bucket wear, and corrosion of magnesium manifolds. A brief rattling sound from the camshafts upon starting the engine might sometimes assist in identifying certain camshaft problems, however it may not reveal all difficulties.

The headbolts were replaced once the engine reached serial number 60-060,658 or a similar number. Indications that the bolts are missing include a decrease in coolant levels, the presence of coolant in the oil, and oil in the coolant. Additionally, the appearance of check engine lights serves as a warning indicator.

It is advisable to replace the engine mounts about every 40,000 miles due to the occurrence of leaks and sinking. It is also recommended to replace the gearbox mounts simultaneously. There are other mounts available that have a longer lifespan and do not need frequent replacement.


Additionally, doing preventive maintenance tasks such as replacing the fuel injectors is highly recommended, since they have the potential to get stuck and cause engine flooding.

The PCV breather valve is a well-documented problem that may be addressed by replacing it while removing the magnesium manifold. The plastic material of the valve can become fragile and prone to breaking, resulting in leaks.

The engine manifold is composed of magnesium, which is susceptible to corrosion.

Finally, the transmission itself may provide issues. I have encountered problems with my vehicle and I am planning to return it to the dealership for inspection and resolution.
BuickUS4
Senior
Posts: 58
Joined: Thu Feb 24, 2022 4:35 pm

Thank you - that information is quite helpful. Are the bolts suitable for this FL?

I am not very worried about the MCT box as it has been serviced and is capable of handling 1050nM in my E63 without any issues.

In my research, I have found that the problems with the camera are the most worrisome.
BuickUS4
Senior
Posts: 58
Joined: Thu Feb 24, 2022 4:35 pm

I am now questioning myself. Can anybody confirm if the noise that occurs upon starting up is the same as what I previously described?
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