asaud7

I just took my car to the dealership for the airbag recall replacement and the service advisor listed a slew of repairs including a new intake manifold and throttle body, power steering pump replacement and valve cover replacement.

I still have some time on my aftermarket warranty so I approved the repair work to be done but was shocked when I picked up my vehicle and saw that the valve covers are plastic. When did Mercedes-AMG go with plastic versus aluminum? Wouldn't that compromise the engine in the long run?

Overall, the dealership experience was fine until I noticed that they didn't replace my engine nameplate on the manifold intake and wipe down the engine and some of the hoses

roadkillrob

The black ones started sometime late 2010 early 2011 I think, but I also always thought the silver early ones were plastic also.

asaud7

No, I'm pretty sure they were aluminum, but can't verify.

G_Money

They switched when the facelift cars came out.

asaud7

Ahh, that makes sense. So the PFL's had aluminum and then they switched to plastic. I wonder why?

roadkillrob

Why did they replace the ones on your car, did the crack or warp or something, maybe that is why they switched if they found a flaw in them, haven't heard of too many issues with the plastic ones, but obviously they are cheaper to make I suspect.

asaud7

I think it was a money grab to be honest. The intake was cracked, but I didn't think the valve covers would need to be replaced.

Two years ago it was headbolts and this year it's this. I think it's pretty safe to say that all this engine work will keep this car going for a good while. LOL.

My plan next year was to either sell it and buy a C63s or drive it for another 100K miles.

roadkillrob

Nice, intake was good to get done on someone else's dime, black valve covers look better anyway in my book!

ItalianJoe1

Plastic is better for noise, temperature control, doesn't warp as easily as the long thin metal covers, has many advantages. It's not a downgrade from a metal cover really, and they don't look bad on there.

asaud7

Agreed. The warranty was excellent and even included a loaner from the dealership.

The plastic covers haven't grown on me yet. LOL. However, it's day one, I'm sure I will change my mind down the line.

asaud7

That's good to know. I wasn't aware that MB even made the change. When I saw plastic, I immediately assumed it was a downgrade. Thanks for the insight. It was much needed.

roadkillrob

I would be BS about my builders plaque though - I hope they have one on order for you!

asaud7

I already raised hell about it. The service advisor wanted to pull my old one which is faded out now, so I'm pushing for a new one. Hopefully, they'll repent and do it.

hachiroku

unless your metal valve covers are damaged there is no need to replace them with the updated parts. your MB Service Center might be trying to get a few extra dollars from you. if you do end up replacing them save them as some folks here might want to buy them. they break if installed incorrectly.

Honro

The plastic covers are prone to cracking because of heat cycling the car. But you have at least 80,000+ miles before any sign of that happens

Vladds

Old ones, PFL ones are not Aluminum, but Magnesium alloy. The plastic ones may not really require the Aluminum bolts, those were necessary for the Magnesium ones.
If I had plastic, I would try to backdate them to Magnesium.