CLK230 W208 boot locking problem

[kardanclk]

Hi all,

I have a rather pressing issue (due to its nature).

I recently bought a clk, it's a lovely car, nearly everything is perfect, but I have noticed that there is a boot locking problem. Here's what happens:

When I use the electric car key and lock the car, the doors lock perfect etc. But, a few days after buying it, being a bit anxious whether everything was closed, I checked the doors (closed indeed), and then checked the boot. I pressed the boot lock in and... it opened! No amount of f*** words helped.

So, below is the list of things I tried:
1) took the metal key out of the electronic one, and tried to lock it manually. To no luck, as it doesn't turn (should it? should it not? - from my understanding of the owner's manual it should). So, I sprayed in the WD40 for the extra magic, but no luck (I did it a few times - nothing happened).
2) Now, I thought - well maybe there's some electrical glitch, so I disconnected the battery, waited a few minutes, connected again, nothing happened.
3) Ok, so fuses left. Checked the fuses (all of them). None was burnt. But, worth mentioning that the car had a few other electrical issues, which I sorted out in a garage (like windows and mirrors not working). Now, two days ago, I thought - I'll go and check the fuses again - the ones in the boot only. Fuse number 5 was one recommended on some forums to be responsible sometimes for the boot problems. Checked it, not burnt. Checked the diagram on the fuse box, it was a wrong fuse in. So, I started to check all the fuses in the boot (a bit of a fuse mess tbh), put them all in the right places, bought some extra ones to put them in order. Then, the engine compartment fuses. A lot of f*** words later, I put them all in order again. Now, this explained to me the previous electrical glitches - some idiot just put the wrong fuses in (e.g. 30A instead of 5A - really makes a lot of sense why things didn't work).

Extra information:
The central console boot opening button works fine. The boot opens when pressing the electronic key. It just doesn't lock.

Any suggestions would be really welcome, before I take it to MB to allow them to rape my wallet.

 

[Dec]

The first thing to do is to get the key to work in the boot key lock, open the boot lid and flood the lock through a straw as illustrated in the two small pictures at bottom of the picture below with WD40, keep the boot lid open to allow the oil to seep down into the lock, repeat and wiggle/turn key regularly, your lock is probably seized due to lack of use.

It can take hours to free up a seized lock, keep the lid open all the time.

I think your key hole slot should turn to the horizontal position, so when the lock is freed up turn the key to the Right so its in the horizontal position and extract the key in that position, this will lock the boot, while the key hole slot is in the horizontal position neither the remote fob or the switch inside the car will open the boot… only the key blade will unlock the boot.

The key may also turn from the vertical position to the 10 o’clock position… I think, is your car a convertible or coupe? Year?

Dec

 

[kardanclk]

Thanks Dec for your help.

It is a coupe (post face-lift 2001).

Spent a whole day yesterday spraying WD40 into the lock, and then I've read that the brake cleaner is a stronger solvent, so I continued with this one.

Still no results. I've put the key into the driver's door's lock, noticed how much of it gets into (this lock works spot on), and then put it back into the boot. There's approximately 1mm difference between the two (with the boot lock being the one where the key lacks the last 1mm to be even able to turn).

I was thinking to hammer the key into the lock to get through this 1mm, but having read somewhere how bad MB car keys are in terms of quality, I might not go ahead with this.

Any further suggestions? Or just keep spraying stuff into the lock?

Many thanks.

 

[davidsw]

The wrong rating of a fuse should not affect anything , as long as it is not too low and keeps blowing! Moving the fuses and getting things to work more than likely points to bad contact rather than wrong fuse rating. I wonder if the boot barrel has been changed but they are known to jam up due to lack of use .Some have had success by oiling the lock and vibrating the key with something like an orbital sander .This jiggles the lock and sometimes frees it up.

 

[Dec]

Keep spraying stuff into the lock, I would go with penetrating oil, as its names implies penetration and that’s what you need right now.
A gentle few taps with the head of a light screwdriver would be ok but don’t use anything heavy like a hammer, Keep the boot lid open all the time so as the oil spread around the lock properly, it wont get to where its needed if the boot is closed.

As you said it’s the last mm that’s the problem, that key wont turn until it fully enters the lock barrel, that is, to the same distance as the door lock.

Its better to get the key working in the lock, this might then reveal why that boot is not locking when its slammed shut.

When you slam the boot shut can you immediately hear a vacuum pump running or any other clicking?
If you put a digital camera (or a recorder) inside the boot with the sound turned on you will hear anything that goes on immediately after the boot is slammed shut.

Dec

 

[kardanclk]

Thanks for all the tips. The car was yesterday in a garage for wheel bearings, and I asked them about the boot lock as well. They ended up saying that I'd probably need a new boot lock. New one from Merc is around £360 (inlc. VAT), as it needs to be made to car's VIN.

What do you think? At this price, I'll keep on spraying the lock as you said Dec. Haven't checked the vacuum pump, but it's a good suggestion - I will.

I hope that it's just jammed and it will start working again. I don't have orbital sander, but hopefully I don't have to go to these lengths to make it work.

 

[Dec]

The important thing is to get the key to go the full distance into the boot lock key hole as the door lock, it should turn when it’s fully in the lock.

See this here… http://www.mbclub.co.uk/forums/general-discussion/90291-cant-get-into-boot.html
While pliers may give you a better grip of the key, don’t apply any pressure until your sure that the key blade has fully entered the keyhole, if you over do it and apply too much force you will snap the key in the lock.

When you lock the car in the usual way with the remote, you say you can open the boot by pressing the lock inwards… do you hear the vacuum pump running for about 2 seconds when you press the lock inwards?

Is the keyhole slot in the vertical position like in the picture above?

Nobody knows your boot is not locked so you are bluffing it for now, try a little while longer to free up the lock, replacing the lock will cure the seizure of the lock but the fault might be elsewhere like with the vacuum pump.

Dec

 

[Mil1194]

The important thing is to get the key to go the full distance into the boot lock key hole as the door lock, it should turn when it’s fully in the lock.

See this here… http://www.mbclub.co.uk/forums/general-discussion/90291-cant-get-into-boot.html
While pliers may give you a better grip of the key, don’t apply any pressure until your sure that the key blade has fully entered the keyhole, if you over do it and apply too much force you will snap the key in the lock.

When you lock the car in the usual way with the remote, you say you can open the boot by pressing the lock inwards… do you hear the vacuum pump running for about 2 seconds when you press the lock inwards?

Is the keyhole slot in the vertical position like in the picture above?

Nobody knows your boot is not locked so you are bluffing it for now, try a little while longer to free up the lock, replacing the lock will cure the seizure of the lock but the fault might be elsewhere like with the vacuum pump.

Dec

Hi,

I know this is an old thread but I bought an old 320 and locked the keys accidentally in the boot.
The RAC came out and broke in and took the rear seats out and gave up when they saw the pumps etc for the roof. They called a locksmith (cost me £90) and they couldn't get into the boot lock either as apparently nobody uses it as you normally use the buttons etc. We broke a light to get in and got the keys out but being as we never use this car - have a cl500 as a daily - whenever the battery is flat on the 320 have to use the jump point under the bonnet and then lock/unlock the car on the button and then switch the ignition on and off so you can access the boot (with the interior switch....) if the battery was completely knackered you'd be screwed as my key won't go all the way in.... Now my roof is playing up - the pump will not switch off and im convinced it's to do with the headrest switch- the car has only 3000miles in the last 10years and I even found a set of false teeth!!

 

[Dec]

The metal key is for emergency entry into the boot, it is vital that it can open the boot, if as in your case, the vacuum pump has become faulty.

The lock is probably seizes, open the boot lid and keep it fully open and flood the lock key hole with WD40 as often as possible.

You will need to examine the vacuum pump in the boot for damp/wet and check the electrical connections for corrosion.

Is the car always garaged or out in the open?

Dec