Alarming tyres on first Merc

[dervmerc]

Hi, another newbie grateful to be a part of this forum. I've been reading the posts and there's a lot of knowledge about Mercs on here.

So, with my first post may I ask a few questions about my 2002 220 cdi?

I've had it a couple of months now and found I was getting nervous about a few things which a quick read of the volume that is the owners manual laid to rest.

Currently I've had alarm immobiliser problems which are embarrassing but I'm thinking it's just the batteries in one of the keys I was using.It would open shut doors but would'nt recognise the key.If I left it a short time it seemed to reset and off I went, would the key batteries be the likely problem?

The other thing thats irritating is a low whine from rear axle area especially when running up to a stop.I took it to an indie and they said it was the tyres. They are all the same make and quite new but a low profile not well known make as far as I know. The tread is a pattern that arcs into the middle,sure you know the design.Would the tyres be the likely cause?

Sorrow if thats a bit much for first post. Thanks for any help!

 

[djb]

does the whine change with power on or off, if no change = tyres
if more whiney with power off, , maybe diff or prop shaft bearing

how manymiles? as merc diffs usually last intergalatic milages.

 

[jberks]

Whine could be tyres - I have similar on mine - sounds like a bearing and there is a slight vibration so I'm not so sure its tyres in my case, but swapping up and down the gears doesn't affect it so it tyres are a candidate - I'm considering fiddling with the pressures to see if that influences it.

On the key front, the key has 2 batteries. One does the open/remote function and that is replaceable. The other is (as I understand it) rechargeable and used for the immobiliser. Its recharged automatically when its in the ignition switch so the problem you describe is quite common when a key is rarely used over a long period. The fix is to simply leave it plugged into the car for a while (as you are finding?) - so leave overnight if you can find a way of securing it obviously - or maybe just go for a long drive.

The other possibility is that the Electronic Ignition Switch (EIS) is faulty. They can and do fail. The normal sign is that its the same with both keys - do you have the other key to try?

If you don't then it would be wise to order a new key anyway - in case yours fails or is lost as it can take a week to get one - not funny if you're parked in a multi-storey! You need docs to order one so speak to the dealer before going down.

 

[dervmerc]

Thanks for reply.The whine seems constant.If I free wheel up to junction it sounds like the noise when your having wheels balanced so could be tyres.It's not excessive but the indie said it was'nt the diff which was a relief.I originally thought wheel bearing but difficult to detect under load on a bend.The specialist Merc people say they get a lot of Mercs with tyre noise so hoping it's that.I can put up with it through life of tyres. It's done 78k miles amd it's a manual.

 

[dervmerc]

Yes I have a second key and am using it now.I've changed both batteries in the key fob I've had trouble with and hope that cures the problem.The charging while key is in ignition is something I knew about but did'nt know if this car had that feature.Can't remember reading that in the manual.I never had a problem first thing when leaving for work or when I left work.It tended to happen when I'd made a stop mid journey and particularly if I'd opened the boot before the drivers door when I returned to the car.After a short time on both occasions it failed,it seemed to reset and then worked.

From what I've read about tyres I'm thinking thats the most likely cause as it does'nt get worse changing gear or speeding up etc.A long trip coming up so I'll maybe know more after that.