Start up behaviour M119

[nic520]

Dear all,

winter time and a topic I have on my „you should ask“ for a long time:
At start up, how does you engine behave (if you suppose your M119 engine is otherwise ok)? I am asking, because the M119 engine on my car turns a little longer as I would expect before firing up. It is not a matter of seconds, but of half a second. I would expect „whowhowhobrooom“ but it always goes “whowhowhowhowhobrooom“. It is frequently driven an otherwise doing fine. No changes lately. I think it has behaved this way always.
Also, when firing up, it is reving up a little at the first 2 seconds before instantly settling for idle rpm.
How does your engine behave?

Nic

 

[195910]

Best to post a video of the startup, we can let you know how it sounds

 

[gerryvz]

Agreed. My experience with a slower than normal startup is either a slowly failing (weak) starter, or a weak battery.

 

[Gatorblue92]

I drove my E420 yesterday for the first time in a few months to clean out the cobwebs and get it turned around in my garage for a few upcoming maintenance projects and it definitely cranked a bit longer than normal. At the moment I’m assuming it’s a weak battery. It’s at least 2 years old and I’m pretty certain it’s actually quite a bit older than that based on what I remember of the maintenance records I got with the car.

 

[sheward]

Agreed. My experience with a slower than normal startup is either a slowly failing (weak) starter, or a weak battery.

+1 I think by now many of our car's starters are becoming due for replacement.

 

[gsxr]

A video would be very helpful.

The starter can be tested with an optical tachometer to check cranking speed.

Higher RPM (~1000rpm or so) for several seconds after a cold start is normal.

 

[gsxr]

At the moment I’m assuming it’s a weak battery. It’s at least 2 years old and I’m pretty certain it’s actually quite a bit older than that...

Load test the battery to verify if that is the problem or not. You don't want to shell out $150-$200 for a new Group 49/H8 AGM and still have a slow starter. 2 years old is brand new IMO, lol.

My beater E420 has a battery dated April-2013 (almost 9 years old), a wet/flooded Duralast 49/H8 from the previous owner. It had been cranking slow for several years. Load tested the battery with a 500A carbon-pile load tester, this showed ~360A at a bit over 10V. This wasn't great, but wasn't bad either. A new 49/H8 AGM should be roughly 400-450A at 10.5-11.0 volts under full load, using the 500A load tester.

I replaced the starter and crank speed went back to normal even with the 9-year-old battery. Might be even faster if I had a new battery in there!

 

[gerryvz]

In general, I'd agree with the @gsxr that a battery that is two years old is pretty much near-new, unless it has been run down.

I would say that on average, if a battery hasn't had active maintenance along the way, a 5-6 year life would be about normal. Every time it is run down, I would take 20% off its life staightaway. If you keep it on a charger or disconnect it between uses, it will last much longer.

I have a battery that is going on six years in our 4Runner, which I disconnect between uses (we only use the truck occasionally, probably 4 times per month). I expect I will get 10-12 years out of it with no issue.

 

[Bogeyman]

My '07 E320 Bluetec built June '06 is on its original battery...fingers crossed.

 

[nic520]

This is the start up with warm engine, cold is not really different.
My batterie might be old: it is a thing with a MB partnumber which must have been bought before 2013…

 

[gsxr]

From that video, the startup time seems normal, but the initial crank is slow - either battery, or starter, or both.

 

[maw1124]

The way the lights flickered during cranking my guess would be battery. Easy check if you have a battery tender at home. Hook it up, put it in Engine Start mode, crank it and see if you recognize any difference. If it’s quick and strong with the battery being helped along, then you know what you know. If the same, then you can look more closely at the starter.

maw

 

[frall]

For me it sounds that the engine is not running smoothly at the beginning. Probably ignition related. But at idle it sounds quite normal. The reason for the (for me) unusual noise at the beginning of the start can also be the exhaust which is probably not original.
The oil pressure is a bit low at idle (for the neutral position).

 

[nic520]

Hi,
yes, it is a different exhaust and I think it is idling like that (soundwise) for the last 20.000 km (without touching the distributer caps). I should have a look into the caps, also since I wanted to add the proper venting for a long time.
Oilpressure is ok from my point of view, allthough it is cold outside at the moment, I came back from a faster testdrive when doing the video. Oil must have been hot at that moment. Eventually I was surprised the pressure was that high…
The pressuresensor by the way is new from MB, the old one from Febi or Metzger (don t recall) lasted only 20k km. The Febi was 25€, the MB part was 116€. The new one shows a little bit higher pressure at any condition. The old one failed by dropping to „0“ at idle, which is scary when it happens at a traffic light.

 

[nic520]

just checked ignition voltages - ok for me.

 

[Gatorblue92]

Load test the battery to verify if that is the problem or not. You don't want to shell out $150-$200 for a new Group 49/H8 AGM and still have a slow starter. 2 years old is brand new IMO, lol.

My beater E420 has a battery dated April-2013 (almost 9 years old), a wet/flooded Duralast 49/H8 from the previous owner. It had been cranking slow for several years. Load tested the battery with a 500A carbon-pile load tester, this showed ~360A at a bit over 10V. This wasn't great, but wasn't bad either. A new 49/H8 AGM should be roughly 400-450A at 10.5-11.0 volts under full load, using the 500A load tester.

I replaced the starter and crank speed went back to normal even with the 9-year-old battery. Might be even faster if I had a new battery in there!

Went back into the service records and my battery is actually 7 years old so might be due for a replacement but I'm sure the starter is also a bit worn out and suspect. Car still started right up but just cranked a bit longer than I was expecting. FWIW I have been getting 13-16 years out of the battery in my 240D which is currently dead and will get a replacement battery in the spring. Not surprising on that one since its a garage queen and doesn't use much electrical power aside from starting and the glow plugs.

 

[TerryA]

This is the start up with warm engine, cold is not really different.
My batterie might be old: it is a thing with a MB partnumber which must have been bought before 2013…

What’s wrong w/ that. Sounds great to me. Starting is not always instantaneous. The engine has to at least turnover once.

It’s not broken don’t try to fix it. If you think the battery is to old replace it and move on!