Lot of grief with my W210 E320 Estate today

[Peter DLM]

Driving to a location an hour from home, about 30 mins into the journey the dash claims that the BAS has failed, and then a minute later that ESP has also failed. Then 5 mins after that another warning saying 'Battery/Alternator failure' and 'Visit Workshop'.

Now as the first two problems happened 9 months ago and disppeared by itself I ignored it. I also ignored the battery/alternator one as well, thinking that after I restart the car it'll all be ok.

Left the car parked for 6 hours and when I flicked the ignition on, the Comand system advised starting the car within 3 mins as the battery voltage is too low. I've had that warning for a year, as I only use the car once a week/fortnight for short journeys and after a 30 min drive it was all ok.

Now, I was quite shocked to see it after a sold hours driving. It seems fine and I drove off with the sat nav on and the climate on full. The Battery/alternator warning still on. 2 mins later the Comand turns off... I start thinking 'here we go' Then the car looses a lot of power, foot flat to the floorboards and baring reaching 10mph. I pull over and it all dies. Just a 'dead battery' click when you turn the key.

Wait 10 mins and it starts again, but won't change out of 1st and 20mph is the top speed.

My mate is behind me fortunately, we install his battery into my car. I suffer the indignaty of a V reg Renault Laguna diesel Estate saving my merc..... We drive 40 mins to his house, the battery/alternator warning still on. I'm sure I am running a total loss ignition system and leave everything off. The BAS and ESP warnings are gone, and instead a sold dim battery/alternator warning.

We leave a battery charger on the merc for an hour and deem it safe for me to make the 30 min run home. Mistake !! I make it two minutes before I get the loss of power and 10 mph max speed and just about make it back to his house. The battery is completely dead, the thinking is now that there is some sort of earthing issue and the car was draining the battery all the time it was parked, despite the charger on it.

Another fresh battery into it and I drive home. This time NO batter/alternator warning, but the BAS and EDP warnings are back.

So, what the hell is going on?

Alternator seems ok, but it's charge not making it to the battery. Is there a regulator of sorts to manage the battery charging? Could it be screwed and dumping all the alternators charge to earth? What drained the battery so fast when parked? There were no visible signs, did it all drain to earth as well?

 

[television]

BAS and ESP do need the full 13.8 running volts from the alternator, your other symptoms also indicate a low voltage.

You must have a faulty / intermittent charging system.

I would take it to a Bosch Service center, I can give addresses if needed and ½ the MB price

 

[Dieselman]

How do you know th ealternator is Ok, the regulator is built into the back of it.

My guess says brake light switch for the BAS/ESP warning and the alternator regulator/diode pack or one way pulley for the not charging.

You only had to have the indignity of the Renault saving you because you haven't attended to previous warnings.

anyway..Welcome.

 

[karlefr]

Never ignore warning lights!

Well, you know now what happens if you do!

 

[Peter DLM]

Thanks for the responses chaps.

Yes, I know that it was remiss of me to ignore the warning signs. But, as they went away after a long drive I assumed that I just wasn't using the car enough.

Malcolm, I'd really appreciate the list of Bosch Service Centres.

Dieselman, the car ran after I disconnected the battery, that's what lead me to say the alternator appeared ok. I guess it's intermitant.

 

[fredfloggle]

Thanks for the responses chaps.

Yes, I know that it was remiss of me to ignore the warning signs. But, as they went away after a long drive I assumed that I just wasn't using the car enough.

Malcolm, I'd really appreciate the list of Bosch Service Centres.

Dieselman, the car ran after I disconnected the battery, that's what lead me to say the alternator appeared ok. I guess it's intermitant.

I'd be very wary about disconnecting the battery on a running MB - in fact I'd be wary about disconnecting the battery on a stopped MB.

 

[television]

Never disconnect the battery when running the voltage can rise and dame components.
http://www.boschcarservice.co.uk/


Just enter your post code on the map.

They have super diagnostic gear and charge ½ what MB charge

 

[Peter DLM]

If the damned thing caught fire I wouldn't care right now.

Charged up the battery overnight and refitted it into the car this morning and fired it up. Voltmeter reads only 12volts, and it should be 14+ so I drove it straight up to PC Merc for them to confirm and install another alternator.

 

[Peter DLM]

P C Merc have replaced the alternator with one of their used ones and all is well again. And for a fantastic price.

I bit the bullet and gave them the go ahead to replace the nearside downpipe to finally get rid of the horrendous noise the cat was making, and the engine warning light will also be extinguished. That wasn't so cheap though, £820.

 

[Peter DLM]

Picked up the car this morning. Everything perfect, all the lights are out on the dash, it's very quiet and seems a little faster as well.

So now I like it again, and wouldn't want it to burst into flames anymore.

 

[television]

Picked up the car this morning. Everything perfect, all the lights are out on the dash, it's very quiet and seems a little faster as well.

So now I like it again, and wouldn't want it to burst into flames anymore.

Not too bad all in all then, alternators do not give much problem these days, and they do have to work quite hard on modern cars.

If it goes wrong again, do not set fire to it in your driveway the after mess is unbelievable.

Happy motoring