W204 C63 Headbolts in 2024
Discussion
I remember these being an issue about ten years ago. Have seen and read lots of threads so know that there is a changeover year around 2010 etc etc.
My question… is this a part that fails eventually on all old cars or are the majority of cars with the original bolts absolutely fine? Any more recent research/articles that I should be reading?
And what happens when they go? Is there enough of the body of the bolt left to just remove the head and twist out or is it a major issue with the block? £2k/£3k bill?
Would be good to hear thoughts. I assume most replies will be from owners saying their car is fine…
My question… is this a part that fails eventually on all old cars or are the majority of cars with the original bolts absolutely fine? Any more recent research/articles that I should be reading?
And what happens when they go? Is there enough of the body of the bolt left to just remove the head and twist out or is it a major issue with the block? £2k/£3k bill?
Would be good to hear thoughts. I assume most replies will be from owners saying their car is fine…
Lack of regular antifreeze changes exacerbates the problem. If you have the early bolts just gave them changed as they will eventually weaken.
Signs of failure are typical headgasket symptoms, and by that stage there is a risk of head warpage due to uneven clamping load. If a bolt head snaps then it isn't the end of the world if caught early but does means heads off. The longer the bolt is left with a snapped head the longer the rest of the bolt is exposed to coolant, which can make them more difficult to remove.
Owners have changed the bolts without removing the heads; by replacing the bolts one at a time. I haven't heard of any subsequent issues when that approach is taken.
Bolts (if early) and cam adjustment plates should be replaced as a matter of course, especially if over 60k miles.
Signs of failure are typical headgasket symptoms, and by that stage there is a risk of head warpage due to uneven clamping load. If a bolt head snaps then it isn't the end of the world if caught early but does means heads off. The longer the bolt is left with a snapped head the longer the rest of the bolt is exposed to coolant, which can make them more difficult to remove.
Owners have changed the bolts without removing the heads; by replacing the bolts one at a time. I haven't heard of any subsequent issues when that approach is taken.
Bolts (if early) and cam adjustment plates should be replaced as a matter of course, especially if over 60k miles.
Thanks for coming back.
Aware of the one-at-time approach from a few years ago. My take on that is I suspect that so many years down the road, the chances of multiple ones snapping on removal must be a lot higher. At that point I’d imagine only really worth going into it being ready to replace one or both heads.
Just curious if there any great sources on the subject. A bit like Hartech on the 996/997.1 engines.
Aware of the one-at-time approach from a few years ago. My take on that is I suspect that so many years down the road, the chances of multiple ones snapping on removal must be a lot higher. At that point I’d imagine only really worth going into it being ready to replace one or both heads.
Just curious if there any great sources on the subject. A bit like Hartech on the 996/997.1 engines.
Tommie38 said:
Thanks for coming back.
Aware of the one-at-time approach from a few years ago. My take on that is I suspect that so many years down the road, the chances of multiple ones snapping on removal must be a lot higher. At that point I’d imagine only really worth going into it being ready to replace one or both heads.
Just curious if there any great sources on the subject. A bit like Hartech on the 996/997.1 engines.
I'm not aware of anything other than Tasos Moschatos discovering and documenting issues earlier on. Aware of the one-at-time approach from a few years ago. My take on that is I suspect that so many years down the road, the chances of multiple ones snapping on removal must be a lot higher. At that point I’d imagine only really worth going into it being ready to replace one or both heads.
Just curious if there any great sources on the subject. A bit like Hartech on the 996/997.1 engines.
mwstewart said:
Tommie38 said:
Thanks for coming back.
Aware of the one-at-time approach from a few years ago. My take on that is I suspect that so many years down the road, the chances of multiple ones snapping on removal must be a lot higher. At that point I’d imagine only really worth going into it being ready to replace one or both heads.
Just curious if there any great sources on the subject. A bit like Hartech on the 996/997.1 engines.
I'm not aware of anything other than Tasos Moschatos discovering and documenting issues earlier on. Aware of the one-at-time approach from a few years ago. My take on that is I suspect that so many years down the road, the chances of multiple ones snapping on removal must be a lot higher. At that point I’d imagine only really worth going into it being ready to replace one or both heads.
Just curious if there any great sources on the subject. A bit like Hartech on the 996/997.1 engines.
Cam adjuster plates I think I would be willing to take on. I replaced the head on my first car 20 years ago. Not scared of doing again, just the hassle and the need for tooling.
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