PewterGreyBenz

I posted a month ago about starting issues with little response and a few funny guys posting without giving viable information at all. I like fun, but to post jokes with real information is simply frustrating and rude.

I have had this problem again and again, sometimes it starts and sometimes it won't right away. So I took the battery out of the car and took it to autozone, where a friend of mine stated the battery was good, and it was at 85%, he stated to put it back in the car and bring it in, so they can check the alternator.

I get this thump, thump, not the normal low battery sound when the engine is trying to turn over, He tested it and said your alternator if going out and it is testing well below 14v.

What is the cost for this item? I would like oem, but are their any other brands worth it? auto zone sells them also, are they any good? is this a diy job, or no, I am not to worried about the stealership, I have a great indy that works at my brother in laws truck shop. Thanks

homeofstone

DYI yes and buy on with lifetime warranty. Have you replaced the CPS unit? If not replace it first. Also, have you had an indie shop that has a Mercedes star scanner check your car? If not do this first and you will not be buying/installing parts you do not need.

vettdvr

Ok,, You are right there are a lot of critics on this site with all the answers but not always to the real questions.

I don't really have enough information to answer you question. But lets start.

IF the engine is running with Head lights on and you have 13.6V or better your alternator is Probably charging. (I can't hook up my equipment to confirm if all 3 phases of the alterntor are putting out voltage)
2) IF while crankin the voltage falls below about 10 Volts you probably have either a bad battery or one that is not fully charged.
3) It is possible on the E series to have the batter control module in the trunk attached to the battery be defective and result in a run down battery. If the car is left for 2 days and the battery is dead totally this might be an issue.
4) IF the engine is turning over normally but won't start the hall effect sensor (Crank position sensor might be defective)
The sensor times when the spark fires and if it is bad you can have fuel but no spark
5) It is also possible to have a fuel pump relay defective and not allowing the pump to supply fuel to the engine

Now where to start. Engine running battery voltage and engine off. You might just have a defective alternator or regulator. Hard to say without putting instrumens on it or reading the codes.

IF it appears to be alternator you should be able to change it and I would consider an aftermarket rebuilt as a possible option vs NEW from MB. There are lots of places that can rebuild an alternator. But check who does the rebuild and totally remanufactured is better than just a rebuild. SO LOOK INTO WHAT THEY ARE SELLING.

IF the regulator is defective buy new.

I bought my MB NEW and drove it for 10 yrs before selling so I have had 1st hand hands on experience in this car. I wish you the best.

PewterGreyBenz

Thank you sir, at 52 years old, I can't get down on my knees as much as I use to. But I appreciate the information, you are right, I need to take it to my mercedes dealer to check it out, my local non mercedes indy is one hell of a mechanic, but he does not access to the necessary scanners as such.

PewterGreyBenz

You have done me a great service and for that I am thankful.



And part numbers and site to get these items would be gladly appreciated. but I won't buy until I go to my indy to scan everything.

vettdvr

You're most welcome and at 67 I don't get under them much anymore either. Just post what the shop finds and we might be able to do more from there.

PewterGreyBenz

lol, you got me their buddy. 67 and still going strong, now i admire that.

vettdvr

Can't be on line too long. I have my plane in the hanger waiting for me to take it out today. Great flying