NTG2.5 in W211 E320 CDI

[cd1974uk]

Hi all,

I purchased a 56 plate E320 CDI last June that had already been retrofitted with the NTG2.5 head unit.

The unit has developed a slight issue in that most of the time, when I start the car i.e. when it cranks over, the unit powers off with a disturbing click of the hard drive, then restarts when the engine is running.

I am obviously concerned that this is doing damage to the head unit.

When I first got the car this was not an issue, the fault seems to have developed over time. On the rare occasion it will remain powered up during cranking. This leads me to (hopefully) believe that there is a loose connection in the back or something.

Any help appreciated.

Regards

Chris

 

[richard]

The noise is the auto-protect mechanism on the hard disk.

What is happening (probably) is as you crank the battery voltage is dropping so far that it thinks the power has gone and powers down the drive.

First, get you battery/batteries checked. 56 Plate could have a 7 year old battery in there and as its now cold everything is under more stress when starting.

Cheers

Richard

 

[Troon]

To see the battery voltage (only one battery in a facelift 211), turn the key to position 1, then press the odo reset button three times.

My tired old '06-plate / 125k mile battery shows 11.7V at rest, and drops to 10V on cranking (at least, it doesn't show lower than that). It's beginning to show signs of needing replacement so I'm saving my pennies.

 

[cd1974uk]

Hey Guys,

Many thanks for your help. I was out today pottering around town and I started the car probably 5 times of which the head unit stayed powered up once, when the car was warm.

I can get a Varta H3 silver for around £80, which may be money well spent if it means risking killing the hard drive.

I am finding myself wincing every time I start her up at the minute, so will get the battery checked forthwith.

Regards

Chris.

 

[cd1974uk]

Hi again.

I am seeing a drop down to 10.2V on cold cranking. The battery is 12.4V at cold rest and goes up to 14.4V with the engine running.

Am I right in thinking then that this voltage drop would cause the NTG 2.5 to shut off and I should be thinking about a replacement battery. The car otherwise starts fine with no errors on the dash.

Regards

Chris

 

[richard]

10.2 is low (and in fact it may drop lower). I'd get your battery tested (or look at the date code on it, and if it looks like the original, just replace it).

The date code is on one of the battery posts, and is week number and year

Cheers

R

 

[cd1974uk]

Great.

Thanks again Richard. It saves me ripping my dash apart again.

Regards

Chris

 

[Beardz]

Guys I've jumped in on this thread as I have a couple of queries battery related

1. Does the voltage on the dash only work on face lift 211's I've tried it on mine (pre face lift) and it won't work?

2. Is the varta h3 battery as good as or better than a MB original? I've heard that varta supply MB which if correct I might as well save my pennies and buy from varta?

Cheers Steve

 

[evdok]

Look on eBay, genuine ones are cheap as chips.

 

[GordonTarling]

I have a pre-facelift 211 and the voltage display works on mine. You have to have the correct screen showing before pressing the reset button - IIRC, it needs to be showing either Temp or MPH.

 

[Troon]

As I said in #3, mine rests at under 12V and cranks down to 10V. I have a new Bosch S5 battery on the way thanks to ECP's 30% sale, hopefully to be delivered today. I'll let you know the numbers with the new battery once fitted.

Beardz: temp display, key to position 1 (not ignition position 2), triple-press reset button — the one that resets the odometer and is the cluster dimmer knob.

 

[Beardz]

Didn't have it on temp display doh!
Thanks for your help

 

[cd1974uk]

Hi all,

I went for it in the end and bought a Varta H3 silver for £78 new. The original battery from 2006 was obviously getting a bit tired. My NTG2.5 now stays powered up when starting so no more butt clenching.

I can confirm that the original MB battery removed was manufactured by varta so hopefully the one fitted will give as good service as the genuine.

Thanks again to Richard from command online for the advice.

Regards

Chris

 

[Beardz]

Chris did you have to recode the stereo/command? I've only got audio 20 but no book or codes so slightly put off of putting in a new battery and then having no stereo (will Merc provide a code foc if I don't get them to do it)

Also where did you order the battery from, as the price is a bit cheaper than I have found for that particular battery?

 

[cd1974uk]

Hi there,

I got it from Tayna Batteries, which is just up the road from me so I was able to collect it.

If you order it online it will be around £10 more.

(Sorry if I broke any forum advertising rules, I am no way affiliated to this company)

 

[Troon]

OK, new Bosch S5 fitted. Results after an overnight in the unheated garage:

Key position I, sidelights on (Auto setting): old 11.8V, new 12.2V
Key position II, "ignition": old 11.5V, new 11.9V
Cranking: both drop down to low 10s, but old battery very sluggish, new starts with alacrity
Full charge on drive: both up to 14.2V
Off after long drive (position I): old drops to 11.9V, new holds at around 13.0V for some time.

 

[cd1974uk]

Hi all.

Just to add that no recoding of the ntg2.5 was required, just had to reset the clock on the dash which was a pleasure to watch those little hands whizzing backward and forward.

Regards

Chris

 

[cd1974uk]

Annoyingly the problem is still there but not as bad.

On a couple of the cold mornings that we just had the NTG 2.5 reset when starting the car grr. voltage drop must be just enough on cold winter mornings.

Why do the later W211's not have the aux battery? The main battery is so flipping far away I'm not surprised there is such a violent drop in voltage when cranking over a big V6 on a cold morning.