99 E320 starts intermittently and now: not at all
 

My first MB, perfect CarFax by the way save one window regulator. Has about 118k miles. One year into ownership, the car began not starting immediately upon turning the key. I wasn't sure if it was under the hood or the key as sometimes it seems as if "wiggling" the key helped...but that's not scientific. At any rate, it would always eventually start after at most five or six tries.

Until yesterday, which was also one of our first 40 degree (F) days here in South Central Texas, when it wouldn't start at all. Just a click. Everything electrical inside is turning on-- lights, A/C, radio, etc.

As far as I know, this car might have the original battery on it.

Where do I start? Thanks in advance.

At the battery, most common issue.

Thanks for the prompt reply. When you say "at the battery," do you mean the battery itself, cabling, terminals or any/all of the above?

He means replace the battery. You should be able to tell when it was installed; all batteries are marked to show the inservice date for warranty purposes. If it is the original battery, then you are way past due. Anything more than 5 years is borrowed time. And yes, functioning lights/radio/etc. but no start is a common failure mode for batteries. If you have any doubts, most auto parts stores can load test the battery.

BTW, the battery is underneath the back seat, on the passenger side.

You'll need to resync the auto-close functions on the windows and sunroof after replacing the battery.

Thanks, guys. Turns out even as second owner, I still got a free jump from MB Roadside Assistance--- I was actually trying the number because I found it in the manual while verifying the boost posts under the hood.

So after 20 minutes of self-charging, she restarts.....but I can't for the life of me find the window re-sync procedure (which I had seen somewhere before)....consequently, the windows are stuck in the down position.

Always something, right? Also, it was an Autozone "Silver" battery, 2.5 years old...doubt it will hold a charge very long if it died on me the first time.

[EDIT]
Got the windows re-synced, she's starting (for now).....thanks for the help.

These cars are pretty sensitive to battery voltage. As the battery starts to fail, it won't start but ext./int. lights will work just fine. To properly test the battery you must remove it from the car's electrical circuits and place a load on it with a battery load tester. A simple voltage check isn't useful.

Some other common issues with a failing battery are loss of window and sunroof sync, BAS/ASR errors and other errors such as 'bad oil level sensor'. If you eventfully need a battery I suggest you consider a MB one from dealer (see below).

All MB owners, regardless of whether they are original owners, can call 1-800-MERCedes for roadside assistance. They will jump start the car, replace the battery, add a little gas and change a tire with the spare. The service is free. They will also arrange for a tow but you have to pay towing co.

Good luck.

Go with the OEM MB battery - mine lasted 8 yrs before dying. MB roadside came out and replaced it in my garage then did the re-syncing.

MB wants $150 for their battery! Is it really that different from other, cheaper brands (with the same cold cranking power)?

Not all batteries are created equal; CCA is not the only thing. The cheapest I found was at Sam's Club, around $90. Be sure you get the correct battery if you go that way, the vent kit is crucial.

If you have an Interstate distributor near you (not just a reseller) you can call and see if they have a blem, they let those go for much less. A guy at BW swears by those deals.

Well, got the MB battery yesterday. Just now took three tries to start. What the....?

All I know so far is that the first start today (day after new MB battery) took three tries; two other starts since then it started right up, no problems. I really needed this to be the battery; I'm on unemployment right now with a job scheduled to not start until January....dang. Is the question now what would let the battery take some kind of hit over night?

SO when you say it takes three tries to start, what does it do the first two tries? Does the engine spin? Does nothing at all happen? Does it make some noise, but not the "right" noise? We need a much more detailed description of "not starting" to offer any help.

Good point: tries to start meaning the starter turns over but the engine doesn't catch. (first try). 2nd and 3rd tries no problems: 2nd try after sitting at a destination for 3 hrs. 3rd try after a short drive after the 2nd (good) start.

Been doing more googling on this....could it be the crankshaft position sensor issue that I've seen in several places?