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2000 E430 4Matic 142,000 miles
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70 Posts
Discussion Starter #1
Considering replacing the voltage regulator on my 2000 E430, 142,000 miles as preventive maintenence. I have vehicle service records but nothing shows up about alternator. What has been your experience with lifespan on these units? My friend just replaced alternator on his 98 E320 with 115,000 miles. Left him stranded. Any input suggestions greatly appreciated.
 

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E320/E250 Bluetec Ford F350 6.7l
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36,372 Posts
I think you got your money worth on VR.
When they can last 200k miles on CA cars, where you don't use headlights much, no rear defroster, the consequences of failed $45 VR when long distance from home can be devastating.
 

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1998 E320s sedan and wagon
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972 Posts
They usually don’t just quit. Maybe replace it as a preventive measure when you have low voltage indications - battery goes flat, windows out of sync, random SRS faults, etc. it still might not be the cause then.

Sixto
98 E320 wagon 197K miles
 

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2000 E430 4Matic 142,000 miles
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Discussion Starter #5
They usually don’t just quit. Maybe replace it as a preventive measure when you have low voltage indications - battery goes flat, windows out of sync, random SRS faults, etc. it still might not be the cause then.

Sixto
98 E320 wagon 197K miles
I see your wagon has 197k miles on it. Have you had to replace its alternator or VR?
 

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1998 E320s sedan and wagon
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I’ve had this wagon since ~160K miles. Few receipts records so I don’t know if the alternator or VR was replaced. I haven’t touched them. I replaced the battery because there was a good deal on an AGM.

On 126s and 140s I replaced the VR when the ABS and ASR warning lights came on for no seeming reason and the warning lights went away. At that point one brush was dirtier than the other suggesting it was too short or the spring too worn for good contact with the armature. New brushes might haves fixed things but I didn’t care to learn a new skill.

FWIW I replaced the water pump (started leaking), belt tensioner (noisy pulley) and idler pulley (noisy pulley) a couple of years ago, then the thermostat last week. Seems to take forever getting to operating temp in mild SJ winter but the new MB thermostat didn’t change that.

Sixto
98 E320 wagon 197K miles
 

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2000 E430 4Matic 142,000 miles
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70 Posts
Discussion Starter #7
I’ve had this wagon since ~160K miles. Few receipts records so I don’t know if the alternator or VR was replaced. I haven’t touched them. I replaced the battery because there was a good deal on an AGM.

On 126s and 140s I replaced the VR when the ABS and ASR warning lights came on for no seeming reason and the warning lights went away. At that point one brush was dirtier than the other suggesting it was too short or the spring too worn for good contact with the armature. New brushes might haves fixed things but I didn’t care to learn a new skill.

FWIW I replaced the water pump (started leaking), belt tensioner (noisy pulley) and idler pulley (noisy pulley) a couple of years ago, then the thermostat last week. Seems to take forever getting to operating temp in mild SJ winter but the new MB thermostat didn’t change that.

Sixto
98 E320 wagon 197K miles
Thanks for the info! I will post pics of old and new VR's when I get it apart. Hope I'm actually doing some good and not just replacing a slightly worn part.
 

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1998 E320 base sedan @ 160kmiles
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6,214 Posts
Have it load tested. If it passes the rated current test under load, it should be fine. A flaky alternator with worn brushes will not pass due to increased brush contact resistance.
 

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2000 E430 4Matic 142,000 miles
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Discussion Starter #9
Have it load tested. If it passes the rated current test under load, it should be fine. A flaky alternator with worn brushes will not pass due to increased brush contact resistance.
I had it tested by O'Reilly when I replaced the battery 2 months ago. Tested ok. Climatronic shows 13.3 to 13.5 volts with engine running, lights on. So replacing VR may just be my paranoia about getting stranded with a dead car? I've had alternators go out in past on several non-MB cars around 100k to 150k miles.
 

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1998 E320 base sedan @ 160kmiles
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You will get some warning with worn brushes like the ABS/ESP/BAS lights coming on with everything running and coming to a stop or at a stop light. Other things can go wrong too, like the diodes, shorts in the stator windings, etc. It is up to you. That is why I have AAA, up to 100 mile tow service :).
 

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2000 E430 4Matic 142,000 miles
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Discussion Starter #11
You will get some warning with worn brushes like the ABS/ESP/BAS lights coming on with everything running and coming to a stop or at a stop light. Other things can go wrong too, like the diodes, shorts in the stator windings, etc. It is up to you. That is why I have AAA, up to 100 mile tow service :).
Hmmm, 1yr triple a = approx cost of VR...decisions. Kent Bergsma at MercedesSource is a big believer in replcing VR, says they can go at as low as 88k mi. Of course he also sells them on his website,lol!
 

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1998 E320s sedan and wagon
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No idea but it’s another thing that I read fails over time than at once.

If you have a new one, install it then carry the good used one as a spare.

Sixto
98 E320 wagon 197K miles
 

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97 E-420 (180K miles), 97 SL500, (93K miles) 2015 GMC Sierra Denali 2500HD CC/SB/4x4 Duramax(55K)
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on my 97E420 the brushes were worn down quite a bit and the VR was becoming erratic at about 140K miles. Since getting the alternator out of an E420 is a royal PITA I just replace the brush/VR assembly. easy, peazy. Nice thing is that unlike most mfg at least through the 90's MB alternators had a replaceable VR and brushes. Not the case on many alternators.
 

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1996 SL500, 2000 E430
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3,680 Posts
Since my 300E 20 years ago I have replaced them at 150,000 miles or so. I did that on my SL and the brushes, while worn, still had maybe 15,000-20,000 miles left. For some reason one was half the length of the other. I recently bought a 12v extender that plugs into the cigarette lighter and it has an LCD that shows the output voltage. It was pretty cheap at amazon and would be helpful showing a decline in voltage.On my 4300 mile trip it was showing 14.2-14.3 volts - car had 110,000 miles. Of course putting a multimeter on the battery terminals while the engine is running would show the same thing, if you don't mind pulling the back seat out ;-)

I have a feeling though that they will work until one day on the road, usually at the Elephant's Breath Junction - it doesn't.
 

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E320/E250 Bluetec Ford F350 6.7l
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36,372 Posts
You can use climatronic for voltage display, but that not only shows 0.5v lower, but would need setting at each start up.
If you are really technical guy, you might want to add additional monitoring device.
The most popular is ScanGauge, who also works as code scanner, but can be plug permanently and small display can show 4 sensors reading, while you can scroll all others.
The gauge will give you instant mpg and trip mpg as well, so the $150 price will give you lot of fun.
Not to mention that modern diesels require DPF monitoring and prolonging life of $3000 filter can get your $150 back very fast.
 
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