92 400E cuts out after cold start
 

I have a 1992 400E (160K miles) that always cuts out after a cold start, after restarting, it runs fine no more cutting out problems. Don't know where to start diagnosing this problem. Oxygen sensor, alternator????

Also can anyone reccomend any particular fluids for this type of high milage mercedes? I've been using Mobil 1 10/30 syn, for about a year now seems fine?

Someone reccomended Redline automatic transmission fluid, but I'm a little weary about that..

Any advice would be greatly appreciated..

Stay with Mobil 1
 

I am grateful that I have not experienced the cold cutoff problem you describe. I do not know where you would begin to diagnose, but keep us posted to your progress.

In regards to fluids, I have been using Mobil1 since 1996 10W30 5W50 etc any Mobil1 that I can get at good price and season allows, now that Mobil1 0W40 is available I switched to it. (I bought it at Mobil1 0W40 from Advanced Auto Parts cheaper than WalMart). I have only changed the the ATF once at 120K mi, I put in Mobil1 syn ATF. I did not bother draining the converted since the ATF and filter were so clean. I am not impressed by redline products.

92 400E 170K mi

Tough to diagnose
 

I'm at a loss to help you diagnose your cold start problem. I don't believe it's O2 sensor related, as the O2 sensor only starts working after it's reached a high temperature - which would take some time even if it's electrically heated.

Fuel pressure / delivery may be something to check.

As far as the fluids go, I like Mobil 1 15W50. California would be a good place for this viscosity - I'd only go to a lower one if the temps got below zero - not too likely in California unless you're vacationing with the Donner party.

I wouldn't waste my $ on synthetic ATF - I don't believe that MB recommends it for this transmission. Drain, change filter, and ATF fill every 15k with MB recommended products should do you fine.

Also - make sure you drain your antifreeze every two years, and use the MB product to refill. All of my BMW and Mercedes mechanics tell me that this goes a long way towards preventing problems.

Good luck finding the cause of your problem - please share your remedy with us if you get it solved.

Troy
1995 E420 75k

cold start
 

I had the same problem with my 400-E. I sprayed an entire can of Holley carburator cleaner into air intake with the engine running of course & the air filter box removed. You'll have to keep the engine above idle speed to keep if from choking on the cleaner. If your not experienced with type of precedure be "carefull" . Don't let the fan blow it in your eyes. Wear saftey glasses. The problem is carbon build up in the intake. Some of these cleaners work much better than others so you may have to experiment to see what works best according to whats availible in your area.

Be careful
 

Make sure that you're not getting carb cleaner on your mass airflow sensor - it can easily foul it, break it, and cost you a pretty penny.

Troy
1995 E420 75k

Mobil 1 5W-30 and 10W-30 are no longer true synthetics. They have changed them to a petroleum base to compete in profit with another oil company that got away with doing it. M-B no longer recommends Mobil 1 5W-30 or 10W-30 oils. You can verify that these oils have changed because the pour points are now much higher than the old ones.

If you must use a light weight oil, Mobil 1 have come out with a new true synthetic called 0W-30. I personally would use 0W-40 in cold weather or 15W-50 Mobil 1 in any temps about zero. These are true synthetics.

15W-50 Mobil 1 has the most anti-wear additives and is used in many types of race cars. I remember seeing a team sponsored by another oil company having Mobil 1 15W-50 added during a pit stop.

Low viscosity oils are pushed by big American and Japanese auto makers to help them with their Corporate Average Fuel Economy (CAFE Averages based on the Moss/Magnusun Act). They make almost no difference in fuel economy in real world situations.

If it wasn't for this bill, you'd never see automotive engineers recommending 30W oils.

mine too
 

My 1992 400E does the same thing in cold weather, Just last night it did it. Ofcourse it was 7 degrees here, so it was damm cold. It started up fine, i put it in reverse, and it died after about 10 seconds. I started it up and it ran fine.

From what I can gather from the 400E after having it in multi-seasonal NY, These cars just dont like cold temperatures.

Run some BG 44k through w/ 1/2 a tank
 

You could have some carbon buildup on your intake valves. While not as effective as cleaning from the intake side, a can of BG 44k fuel system cleaner put into 1/2 a tank or less will help. If you don't have this product available near you, Chevron's Techron product is a good alternative - and it's available at all automotive stores and Chevron stations.

Of course - deposits could have nothing to do with your problem, but I always like to try the quick and easy solutions and move on to the more costly solutions as a last resort.

Troy
1995 E420 75k

Re: Be careful
 

That's hard to do with the M119's intake setup.

Intermittent start/run problem could be that the TD terminal of your tachometer has an intermitent short which makes the fuel pump relay not activate. Detach the connector from the tachometer; if this eliminates the fault, replace the tachometer.

Cold Start Problem Gone
 

Thanks for all the advice. What finally seems to have done the trickwas cleaning my system out with that techron fuel additive.
Ran that thru my system twice and I haven't had a single cut out since. My 400e used to cut out every single morning like clock work.


Thanks Again