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Mercedes Trunk Lid

I recently purchased a 2004 MB S430 4Matic. It’s wonderful, except for the manual release trunk. Opening it, it sounds like a truck, and it’s difficult to close. I had a '98 BMW with a manual trunk, but it was a pleasure to open or close. Are there better pneumatic struts to correct this “problem?” How much would it cost to replace with an automatic trunk (I’m sure way too much). I realize I’m nitpicking, but it’s the only thing on this expensive car that really feels–and sounds–cheap.

This is too vague a description. What do you mean by manual release? Are you lifting the lid from the rear or pulling a lever from within? And what is making the noise? Hinges, cable release, struts, sheet metal? Have someone else help you determine the source of the noise.

It’s possible you can convert this trunk lid yourself to an electric release. There are kits available for as little as $21. See here: but it won’t help you silence the noise until you determine what’s actually causing it.

Thanks for your website. It might help. The manual release is from the car itself (on the driver’s side near the automatic window toggles, and from the key fob. It’s not bad, just annoying (since my '98 BMW 740iL had a manual trunk that was very smooth). Since I don’t know a lot about mechanics, I think it could be the struts, hinges, or cable release. Like I stated, I love the MB S430, except for this. I will eventually take it in to a mechanic or body shop to see if it can be cheaply fixed. The dealership where I bought it showed me other “manual” release trunk lids and all seemed the same. Since I got a good deal on the car, I’m not really too concerned about this–it’s just that I’m obsessing about its faults since I just bought it. Thanks, again for the website you wrote me about.

Using the key fob is a manual release? I always thought that was having to put the key in the lock on the trunk and turning it. I think what you have is an electric release and you may be hearing the servo if it is not one of the things that SteveF mentioned.

It may be an “electric” release, but not electronic. The automatic electronic trunk lid has a button that you push that will automatically (and quietly) close the trunk. The key fob may open mine (clunkyly), but you still need to manually push down on the trunk to close it.

Sorry, that is a little past me, I still crank my windows up and down. The link that SteveF gave you was for an “electric release” it won’t make the trunk shut on it’s own.

If it’s not smooth, it might be something simple like the alignment of the release mechanism or something needing lubrication. If it’s “difficult to close” something probably needs adjusting.

go buy a can of spray silicone lube,

spray some (not alot) right into the lock mechanism. see if it helps the noise.

hey it only costs 3.99 or so to try.

So… I’m not sure I understand where the noise is coming from. The noise occurs when the trunk lock releases, or as the trunk lid moves upward?

The noise happens when I release the trunk. It sounds clunky. There is little noise when I shut the trunk, but I have to push HARD on the “latch handle” to close it; then the “latch handle” goes back into the car. It’s just not as smooth as I would have expected from a MB. I realize I’m obsessing because I just bought it, but I can’t help but compare it to my 1998 BMW 740iL. I could complain about the lack of “sunglass” cases and other “pockets” in the rear door of the MB compared to the BMW, but that would be too much.

If you had and old benz, you could also complain about the lack of cup holders (until recently, they didn’t believe in cup holders).

Definitely try lubricating it before you do anything else.