Hi,
I am a new poster here, although I have been reading for a couple years. My 2006 e350 base (63000 miles) had a slew of issues arise after a battery light came on. I had the main battery replaced at Advance Auto after testing determined it to be unstable. The battery light remained on, and afterwards in a short time I had ESP failure, GPS position off by hundreds of miles, and sporadic transmission shift issues. I took the car in for routine service and was told the following:
Auxiliary battery needs replaced (went ahead and told them to do that) - ~$240 (labor included on all)
Steering Angle Sensor needs replaced - $516
GPS Antenna needs replaced - $526
Camshaft Solenoid - $197
Transmission Control Unit and Valve Body - $2350 (was told part for valve body alone was $1100 and $500 for TCU, so $750 labor)

This is an awful lot of things to suddenly go wrong with no prior lights, and the only lights currently on were battery and ESP. I asked if they checked their error messages after changing the aux battery, and the answer was no. I was hoping for a 2nd opinion here.

I've read other posts about one thing or the other, and it seems a lot of these issues can be the result of various things, especially bad voltages from the battery. I figured I would get the most relevant advice if you knew my specific case. I am a serious price shopper, and I know for a fact that my local MB is higher than the average price in the state when it comes to parts and even regularly scheduled maintenance. A service ~ $300; B service ~ $550, compared to $250-450 in other cities. Of course I get a loaner car for buying there, so it isn't worth it to go to another city to save $100.

I really appreciate all the information I have gleaned from you guys the past couple of years. It has saved me quite a bit of $$! Thanks again.

 

Then you should already know that your local Indy is going to beat the socks off your dealer 95 times out of 100.

Just search this forum or the other benzo forum for the local indy in your area with high reviews. My guy here in socal is about 1/3 cheaper then most indys, and WAY cheaper then the dealer - plus they are all former dealer techs...

 

These stealers charged you $240 for a bike battery that you can buy at Walmart, Sears for $35! I changed mine after doing research in this forum last year. I'd suggest you go to a good independent shop for a second opinion.

 

I suspected as much about the battery. I knew I could get it cheaper and do it myself. Unfortunately, I was hoping the other issues were related to the bad battery, so I let them do it. They were not related (according to them). As for an indy shop, I will end up doing that. My next thing to figure out is how much I can save by buying the parts myself and just paying the labor at the indy. I didn't have any success finding the parts at a couple of sites. It might be that the parts I am searching for aren't the actual part names. My other alternative is to fix the steering angle sensor (which is the only error message displaying for ESP) and trade the car before I have to fix the other things.

 

I just called a local Indy, and he said to check that Advance Auto put the right battery in the car. He said by not putting an AGM battery in the car, it can cause a great deal of electrical problems. He said figure that out before I bring the car in for repair.

He also said the battery costs around $300. This seems high, as a I see AGM batteries for $90. Any advice on what battery to use?

Advance installed an Autocraft 49H8 Gold. The product specs don't mention AGM. The mechanic said they use Interstate Megatron 49/H8A which runs $300. However, it doesn't mention AGM either.

 

As for a Non AGM battery causing a great deal of problems -- I have a Bosch lead acid in my 06 E320CDI going on three years and have not had any issues with the battery or electrical system. Bosch cost $99 at Pep Boys and has a 3 year replacement warranty and 84 month prorate.

 

Last year my aux battery was dying. I did a thorough search in this forum. There are lots batteries that fit the bill. I went to Sears and bought it (it's just a bike battery). I forgot the model number but if you do a search in this forum, you will find a number of replacements that fits the bill and a lot cheaper than the stealer and your indy shop quoted you. You can easily replace the battery yourself as I did. It's all in this forum!

 

I just replaced my battery and alternator.
The rear battery was very low and I was getting the red battery warning light. I charged the battery and got the same error. Took it to Dr. Benz here in Las Vegas and he SHOWED me the damage on the alternator. He replaced it with the bosch OEM ($400) alternator and all is fine now.

The rear battery is an Interstate Heavy Duty (They charged it for me for free). I would not suggest buying a cheap battery because the w211 taxes the **** out of the charging system and a Pep Boys or Autozone battery wont cut the mustard.

Why go cheap? You didn't go cheap when you bought the CAR right?

As far as service, find a reliable local indie Euro Mechanic and stay away from the dealer unless you enjoy paying for their nice new showroom.

 

Well my Pep Boys "Bosch" battery is doing a perfect job after 3 years of service in my E320 CDI and it was $99 dollars. Pay more if you want -- it is your money. It is really about being informed and knowing what you are getting for your money. The Bosch I got from Pep Boys is a group 49 and has the CCA and Amp ratings required for the car.

 

Well my immediate concern is the main battery. I already had it replaced months ago. The indy mechanic told me to check if I had an AGM battery BEFORE bringing it in to him to repair the specific issues. He stated that a non AGM main battery can cause electrical problems due to the how the car is interacts with it.
He could have just as easily told me to bring my car in for $2000 of repairs, so I'm looking for some response specifically related to that. The battery I have installed is the only Advance Auto recommended battery for that car. However, it is not an AGM. He was very certain that one of the causes of my list of issues could be the battery from his personal experience.

 

I went through the same drill last year, although i never got the Red light on the dash, my batteries were 8 years old. I replaced the small battery with one from Advanced auto AGM, and purchased another OEM AGM battery for the rear. I recall something about a lot of cranking amps needed and that the AGM batteries have a deeper reserve in cold weather. Both where easy to install so saved on the labor

 

If you must go oem - Parts.com has the oem front battery for $100 and rear for $194.
http://www.parts.com/parts/2006/MERC...bgroup=BATTERY

Mike