TAT,TAT,TAT, TAT,TAT Door Lock Sound on 2006 E350
 

Just recently when I get back in my car after a stop and start driving off, the automatic door lock system on the driver's door goes TAT,TAT,TAT, TAT,TAT as the door lock is going down. Kind of like a machine gun sound. Not making the usual "CLICK" sound like the other doors. I haven't fiddled with it yet,...but want to get an idea as to what it is and is it fixable by me? Thanks!!

Could be the lock actuator going bad. See this link.

https://mbworld.org/forums/e-class-w...lems-help.html

My e320 only did that first time on startup each day. I had my indie replace the lock actuator. Attached are instructions if you want to tackle it yourself.
Mike T.

Search 'bouncing door lock'... most likely a small spring inside actuator broken, costs few bugs but first time required couple of hour DIY. Garages just replace whole actuator, costs couple hundreds of bugs.

After looking at this answer I went out and tried it; "I have the same problem with my 06 E320..... I took the plunger off (just unscrew it) and took some WD40 and wiped the plunger on the outside then put a little in the hole where the treads are- filled almost to the top. Then screwed the plunger back on the rod and gave it a try. It has been working flawlessly for a little over a week. Only thing I can imagine is the plunger was causing some slight binding or resistance and the WD40 fixed it." It seemed to instantly "solve the problem".

I realized I have probably just bought myself some time before having to bite the bullet and install a lock actuator,...as I probably did not "solve" the problem, but rather put a "band-aid" on it. Thanks for your help!!! Carol

Bouncing Door Lock
 

I would just like to share a quick fix that has saved me hundreds of dollars and cost me almost nothing.

My E350 developed the bouncing lock thing on the passengers side. It was ok for a couple of weeks, then it was really pot luck, whether the car would actually lock or remain open, so parking became a russian roulette of sorts.

Anyway, I looked on Youtube for a fix, all I found was a horrendous procedure that I neither have money nor the patience for!, it seemed to centre around the actuator and for me, the 'cocktail stick' wedged down the plunger worked.
(a very bizarre youtube video from Europe) but how reliable is that long term?

My problem does seem to be a lack of resistance on the door lock plunger. So I got some silver DUCK tape (Duct tape) and it fixed my problem.

Method:

1. remove the plunger from the door (unscrewing)

2. tear a small piece of duck tape, you want to cover the rear 1/2 of the barrel of the plunger, anything more and it will get stuck and that won't be good for your door or the actuator who'll have a really hard time.

3. Put the plunger back in. It should have enough purchase against the door and not bounce like Tigger on acid...

Best case scenario: fixed!!
Worst case scenario: it'll buy you some time before it goes kaput.

Note: mine has been working perfectly for the last 3 months...

Hope this helps anyone who has the same problem. It's not the best fix, but it's a cheap bodge. If at the worst you have to buy duct tape, it's going to cost you $4 + Tax and a trip to Home Depot or some other hardware store.

Thank you for the ingenious "fix"! I will keep it in mind for when mine decides to rebel again. The spray lubricant seems to be really working well,....but I know that all good things must come to an end. When it does,..I will employ your "fix". Thanks again!

Just a quick update, The Duct tape thing continues to work!

Thanks for the update. I can report that the WD40 spray is good for about 6 months as well.....till another quick spray. No way am I spending hundreds to "repair" it. Whether duct tape of WD40,...the "tatatatatatatatat" is gone!

Similar to the duct tape method, I just sprayed two coats of plasti-dip on the stem area of the plunger.

The extra thickness/friction works just fine. I already had the Plasti-dip going because I was coating my EZpass, and whaddya know, it's worked fine for the last 6 months or so.

DING, DING!!! We have a WINNER! Best answer yet!!!!!! Thank you so much!!!!! Instead of lubing,..I will dip-coat it in the future. Thank you!!!!

It's definitely not a permanent solution, as I can see where the dip is beginning to be rubbed off. The good news is that dip is cheap, this piece is easy to remove, and i have no problems redoing it if the need ever arises. :y

Do you think 3m double sided foam tape would be enough to hold these on? I'd rather not do a permanent install.

edit. sorry, wrong thread.

move the rod by hand if theres a lot of resistance then check if something is in the way or grease dried up