1992 300E Engine stalling after cold start. Need help - Mercedes-Benz Forum
LinkBack Thread Tools Display Modes
post #1 of 3 Old 09-15-2005, 09:43 PM Thread Starter
Junior Member
Join Date: Sep 2005
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
1992 300E Engine stalling after cold start. Need help

Hey everyone,

In short the problem with my 1992 300E only occurs during the first 10 or so minutes after cold starting. When I drive and get off the accelerator when approaching a stop sign or rolling down a hill, the RPM needle jumps to 0 and the engine stalls once the car slows down.

Now here is a more detailed explanation:

Again, this problem only happens after cold starting. I think this is KEY when diagnosing the problem. I've had it at several certified Mercedes Benz dealers, but none have found anything because the error simply doesn't happen when they check it out. Also because these older models don't have a hard drive (i guess), the error is not recorded and thus makes it so hard to diagnose. Here is some more info on the car:

It's a 1992 Mercedes Benz 300e. Automatic transmission, 125,000 miles. Get's serviced regularly, and otherwise is in a very good condition. Again, I get oil changed regularly and only tank premium gas (93). It runs at around 600-700 rpms when idle. I bought this car new.

Here is what happens in a more detailed descriptions (please bare with me): When cold starting (after the car has been sitting around for 5+ hours) I drive around, and i guess the cold start protection at first doesn't allow me to go very fast. Anyways, I go slow until it finally shifts up and continue driving. I go over a hill and naturally get off the accelerator to roll down. Immediately after i get off the gas pedal, the RPM needles JUMPS (that's right, JUMPS) to ZERO. However the engine doesn't stall at this point. IT STALLS when the car slows down at the base of the hill. That is, the car doesn't stall while I'm moving at a certain speed, only once it falls bellow a certain speed. Since this occurance is quite frequent, I learned to prevent the stalling of the engine, by accelerating furiously. Sometimes, if I'm lucky, the rpm needly gently moves to the regular RPM for the specific gear, and the car runs fine. If I do nothing, or I can't accelerate and I have to slow down, the ENGINE STALLS, all the lights turn on and the steering wheel is hard to turn.

When this happens I stop the car, put it back in PARK, and try to restart the engine. Sometimes it takes a few minutes, other times it starts up immediately.

Again, after this, sometimes the problem doesn't occur again, other times the same thing happens at the next stop sign. But after about 10 or so minutes, the problem is gone. Note, this also happens when the engine has reached normal operating temperature of around ~80 degrees.

While this is the main problem, I've also encountered another problem twice when I'm at a complete rest, and want to accelerate and then the engine stalls immediately. This problem is less frequent yet ALSO only happens during the first 10 minutes of cold start.

I really want to STRESS that the problems ONLY occur after a cold start. I've searched the board and seen people with similar problems, however the suggestions didn't really make sense to me, nor do I think they apply to this problem. If this ONLY occur during the first 10 min after cold start, what could be the problem?

What specifically runs during the first 10 minutes after cold starting that does NOT run otherwise? What happens that simply doesn't happen when the car has been running for a while? I've tried letting the car warm up for several minutes, yet the same problem occurs? This is simply mind boggling and I don't know what to do. Dealerships can't help me as they can't diagnose it. The car overall is in a good condition and I don't want to lose it.

I'm completely at a loss, and hopefully some of you can lead me in the right direction. I would appreciate it SO SO SO much. It's a beautiful car, and I'm scared to drive it, get stuck in traffic, and have it stall in the center lane .

Again, thanks in advance for your help and for reading this.
redrabbit is offline  
Sponsored Links
post #2 of 3 Old 10-25-2005, 04:34 PM
Junior Member
Join Date: Oct 2005
Location: ABQ
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
What "runs" at cold start are cold start injector and idle control valve.

Also a problem are vacuum leaks, which can defect the cold start system's attempt to provide rich mixture.
lkchris is offline  
post #3 of 3 Old 10-29-2005, 09:34 PM
Junior Member
Join Date: Oct 2003
Location: Escondido, California
Posts: 3
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I had the same exact problem but mine stalls after approx 20 minutes of driving. It's like clock work! Had it towed 3 times in 2 weeks. But then I discovered that after letting it cool down for a few minutes, it starts back up again and drives for a few more minutes. I since changed the OVP relay. fuel filter, voltage regulator, ignition coil and finally, ignition module based on inputs from other forums but none fixed the problem. I even replaced all the vacuum hoses and lines but to no avail. Frustrated, I took it in to our local dealer and they found a crankshaft positioner sensor defective. The part was $160 plus 3 hours of labor ($270). I've driven it for two days now and so far, no stalling.

Considering the cost of all the parts I replaced (some used) I could have taken it to them much sooner and saved a bunch but like many of us, I tried to avoid the steep dealer repair cost if at all possible. On the other hand, the parts I replaced are now newer than the car so hopefully they won't fail right away. I hope my experience helps you decide the best option. Good Luck!
bricksb is offline  
Sponsored Links

  Mercedes-Benz Forum > Mercedes-Benz Enthusiasts Forums > DIY/Tech Help

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome