Cold Starting Question
 

I am currently in Mammoth Lakes, CA.
Since I have never had my car in the cold (albeit Big Bear a few times)... I have noticed that when the car has sat overnight, and I try and start it in 20 degree F weather... it won't start until you actually release the key.
In detail... I will turn the key and hear the starter going, after about 4 seconds when I notice the engine has not caught on, I would release the key; as soon as I release the key, the engine starts. It doesn't start when I have the starter going, but rather seems to barely catch right when I let go. This has happened multiple times, and if I keep turning the key for 10 or so seconds, the engine will still not catch until I release the starter/key.
No problems, just curious? Thanks!

Are you talking about the CLK? If so, I thought the newer models have a different ignition switch which allows you to just tweak the key to the start position and then let go, and the engine will automatically crank for as long as it needs then stop. Could this be what's going on? It's kind of an unusual thing the first time I drove a car with it (a 2001 ML I was looking at.)

David, you probably have a weak battery. The starter is taking most of the power & the ignition system isn't getting enough power. What weight oil do you use & is it synthetic?

It's a brand new (about 10,000 miles old) Mercedes-Benz battery! And i'm using synthetic oil, Mobil 1 10w 50.

So hmmmm?

I was going to post a similar thread on this.

We drove the 260E up to the mountains and it displayed similar symptoms on cold start only.

I am, as you are, baffled.

Perhaps its the fuel distributor?

Speaking of weak battery.

A few days ago, my 87 300TD took two cranks to start at 33 deg F. That was a bit odd as it had always started on first crank.

Looked at the records and found a new MB battery was installed about 1 year ago. It is one of the maintain type that you add water, etc.

So I opened the holes and filled with distilled water. Oh, boy, it took half a gallon to fill all the holes. The liquid must be seriously low. After adding water, I put on the 1.5 A automatic trickle charger (just purchased). It took about 5 hours for it to fully charge and the charger tuned it off automatically.

Now I cannot believe the difference. As soon as I crank, the engine starts. Also there is no smoke after I glow it once. Before, I always see some smoke at startup.

My conclusion is that the weak battery is not running the glow plugs hot enough and not turning the starter faster enough.

I then used the charger on my other two cars. My 300E has one of these maintenance free type battery that has a hydrometer check on it. It was green and the instruction says it should be 50% - 100% charged (a big range). It took 4 hours for the charger to turn off.

The E320 was even lower on charge. After 5 hours the charger is still on so I went to bad and let it charge over night. In the morning, I checked and the charger was turned off.

You may want to use one of these automatic trickle chargers just to make sure it is fully charged.

David,
I don't mean to be dense but I'm going to ask again. Do you have the "autostart" (not its real name) feature where you don't keep the key in the "cranking" position, you just quickly turn it to the crank position and immediately release it?

I'm sorry 400E, I forgot to answer that question! No, my 1995 C280 does not have the "SmartKey" (TM). ;) They started the SmartKey in 98 for the 202 chassis.
So I'd rule that out as being a culprit.

But it was so weird... yesterday morning, it was 18 dF in the morning when I started my car (BLIZZARD!!!!). It was really weird... because I cranked it for like 4 seconds, noticed that it didn't start, and then when I released the key (/starter), it caught and started right up! After a short drive and coolant temps about 50 dF, I restarted the car after stopping, and it started normally (cranked for only a second or two, me releasing the key when the engine caught).

How strange! I am certainly tapped out but will stay tuned to see what turns up. . .

I was just thinking... my coils are bad....
maybe that is why it did this!? :confused: :o