So... How long does the original alternator last on a '95 E300D? - Page 2 - PeachParts Mercedes-Benz Forum

funola · #16 02-12-2015, 02:10 PM

Quote:

Originally Posted by Maxbumpo

My '95 E300 alternator has no replaceable voltage regulator. The original was a Valeo, the replacement alternator is a Bosch. This is NOT like the earlier 124 cars. I suspect that all '95 E300s are the same.

Mine died around 320k miles, during the summer while driving to Charleston SC from up north. This was either a Saturday or Sunday. We stopped for dinner close to sunset, came out and it was dark, car started fine but after we got back on I-95 I thought that the instrument cluster illumination was a bit dim, so I turned it up. Shortly after that I realized that the headlights were also getting dim, and then the ABS light came on, and I new I had a problem...

Wife and young daughter were with me, so we went over the options: (1) stop and spend the night, fix the next day IF we could find an open parts store; (b) drive home with no lights (another 150 miles to go); (iii) find an open parts store along the way with the correct alternator in stock and install that in the parking lot. We decided on option (iii).

Nearest open parts store was in Charleston (Parks - a GREAT parts store, open until midnight every night of the week). They had the correct alternator in stock, $140. We decided to press on, they were a couple hours away...

Next the SRS light came one, and then the ASD light. Headlights (and presumably tail lights) getting dimmer. Then the two bad things. AC died and the system defaulted to full heat, and there was not enough power to run the windows down or open the sunroof. 80 degrees plus ambient outside, high humidity, full heat into the interior. We shut all the dash vents, but heat continued to pump into the foot wells and through the windscreen defrost vents.

I pulled off with the idea of getting a vicegrips from my toolkit in the trunk and clamping off the coolant flow to the heater core, but I had full-mechanical locked the trunk, and I could not shut off the engine to use the key to unlock the trunk.

We continued on. I stuck in the right lane, following a semi-truck so his lights would be visible over/behind us.

We finally rolled into the parking lot of the parts store, I left the engine running while I went in to get the alternator, and made sure it was the correct replacement alternator before I shut off the car. Took about 30 minutes to get the new alternator installed, then I got a jump from another customer and we were back on the road, 100%.

I have a similar story in a Peugeot. 1000 miles from home and alternator started to charge intermittently, progressively getting worse. It was daylight and on my way to Autozone hours away, it stopped charging completely. They did not have my alt in stock and new one is 3 days away. Didn't want to wait so borrowed their tools, got the voltage regulator out, saw that the brushes were short but the copper braid had enough slack so I can stretch the brush springs and increased their "length" of the brushes just a little bit . Put it back together and lo and behold it started charging! Made it home no problem.

Lessons learned: Inspect the brushes

Jeremy5848 · #17 02-12-2015, 04:26 PM

Quote:

Originally Posted by Maxbumpo

My '95 E300 alternator has no replaceable voltage regulator. The original was a Valeo, the replacement alternator is a Bosch. This is NOT like the earlier 124 cars. I suspect that all '95 E300s are the same.

That is interesting. Most of my experience is with Bosch; the one Valeo I once owned worked OK but I found regulators hard to find and expensive. Seems to be more choice in Bosch, at least in the States.

As previously noted, the regulator is under the black plastic cover. Specifically in the case of the 1995 E300D (W124, OM606NA) the coolant pipes from the thermostat housing run just behind the alternator on their way down to the heat exchanger in the oil pan. These pipes block removal of the black cover in situ; you must remove one alternator bolt and loosen the other so you can swing the alternator outward. (Or remove the alternator and work on the bench.) The black cover will then clear the pipes and you can remove the regulator. Somewhere I have pictures.

My '95 E300D came with a 90 Amp alternator and I upgraded to a 150 Amp. Both Bosch, same regulator. The 150A alternator was a little bigger but there was room for it--I suspect MB designed the engine to hold any one of several varieties and brands of alternators.

The 150A alternator is great for getting the battery back to full charge; even just after starting and with afterglow still sucking Amps out of the electrical system the voltage is back up to 14+ in less than a minute. I did run a second heavy-duty wire from the alternator to the terminal block next to the battery to handle the higher current.

Jeremy

Chris W. · #18 02-13-2015, 02:44 PM

The original alternator is a Bosch, and yes, it has a voltage regulator. I replaced it maybe 6 or 7 years ago, preemptively after reading some stories on this board. I just looked at the VR and the brushes still have plenty of life in them, so that was not the cause of the failure.

That previous VR replacement is memorable for me for a DIY lesson. I pulled the alternator, took it to the bench and blasted the chit out of everything with spray contact cleaner, installed the new VR, and took it back under the car to reinstall. Was right underneath and tilted the alternator to maneuver it into place when a bunch of unevaporated cleaner spilled out right on to my face and partly in my eyes. Gaaaaah! Dropped everything and ran to the kitchen and flushed my face/eyes for a a while. Fortunately no lasting effects.

Rgds,
Chris W.
'95 E300D, 436K

shertex · #19 02-13-2015, 03:04 PM

Quote:

Originally Posted by Chris W.

Rgds,
Chris W.
'95 E300D, 346K

Chris, did you roll back your odo or something?

Chris W. · #20 02-13-2015, 07:42 PM

D'Oh! A touch of dyslexia rears its head. Trust me, it's 436K. Apologies for that, I'll post this instead of editing above.

Rgds,
Chris W.
'95 E300D, 436K

vstech · #21 02-13-2015, 09:31 PM

I fixed it.
You could put it in your sig ya know...

jay_bob · #22 02-13-2015, 10:20 PM

Quote:

Originally Posted by Maxbumpo

...Then the two bad things. AC died and the system defaulted to full heat, and there was not enough power to run the windows down or open the sunroof. 80 degrees plus ambient outside, high humidity, full heat into the interior. We shut all the dash vents, but heat continued to pump into the foot wells and through the windscreen defrost vents.

I pulled off with the idea of getting a vicegrips from my toolkit in the trunk and clamping off the coolant flow to the heater core, but I had full-mechanical locked the trunk, and I could not shut off the engine to use the key to unlock the trunk.

Monday Morning Quarterback but I thought of the following workarounds:
- Open hood
- pull shutoff vac hose from the I/P actuator
- remove key (it would not shut down now that the vac is disconnected)
- open trunk
- return key to switch
- get vice grips for mono valve hose
- get phillips head for blower fuse
- clamp heater hose
- pull blower fuse
- use emergency sunroof open tool to open roof from trunk
- maybe enough amps removed from the system by killing the blower that you could now open a window
- keep shutoff disconnected just in case

Great story!

Skid Row Joe · #23 02-13-2015, 11:59 PM

Quote:

Originally Posted by Chris W.

Answer: 20 years, or 436,364 miles, whichever comes first.

Additional point of interest: a mostly mechanical diesel is a good vehicle to have when the battery dies. After a jump I was able to drive 20 minutes home with basically zero battery. So when the EMP Apocalypse comes, guess what car will still be driving.

Rgds,
Chris W.
'95 E300D, 436,364 miles with lots of current, now

IF, you bought the car new, yeah, I'd say that's pretty good. But......if you bought it used - unfortunately, you'll never know the care and maintenance, etc. the car has received. If, you bought it from new...... Has the car been garaged since day 1? What type(s) of driving the car? City/Highway? Desert Southwest, Eastern Seas/Saltboard, Upper Midwest? Great Plains, Florida......etc. or ??????

Chris W. · #24 02-14-2015, 01:20 PM

Hi Skid,

I'm the third owner but I have all the records from the first two owners and no alternator shows up. Based on the level of detail present in those records, I'd say it was very unlikely that they would not have logged a new alternator. As regards HOW the car was driven by those owners, you're correct, no way for me to know that. As regards WHERE the car was driven, I can make an educated guess from the records where the vast majority of those miles were driven, based on the shops used and the owners' addresses. Not that either of those aspects of previous ownership would materially impact the alternator life, in my opinion.

Rgds,
Chris W.
'95 E300D, 436K (and for vstech, the reason I don't have this mileage in a canned sig is because I put the current mileage on the car in my post for almost every post)