1998 300D - Puzzle - PeachParts Mercedes-Benz Forum

TX76513 · #1 01-31-2023, 03:25 PM

This one has me stumped so any random thoughts or ideas are acceptable

1999 300D Not a daily driver but frequent driver. Went to turn into driveway and the engine stopped just like you turn key off. Tried to restart several cycles and no go. Got tractor out and pulled into driveway and it started and ran for about 10 minutes and stopped again.
Things I looked at/checked/tested
No codes on my simple OBDII reader
Battery checks good with meter and load tested good.
No obvious wiring defects, unplugs, anything obvious out of order. Car is kept pretty tidy under hood.
Fuel Filters replaced in November 2022

I was hoping to catch a code to give me some where to start but nothing written or pending. It started right up this AM and was looking under hood when it shut down. Its just like someone turned the key off.

Thoughts, Ideas?
John

shertex · #2 01-31-2023, 03:45 PM

If you've never done so, I would replace the K40 relay. Notorious cause of hard to diagnose issues...including engine dying randomly.

TX76513 · #3 01-31-2023, 03:59 PM

Its a good thought - I had 3 W210's and ran across that before but another issue like you mentioned. Now down to two the 300D and a 2000 320. I have a spare K40 will have to look at the part number as it was out of a non turbo 300D. Been selling off a lot of the heard

when you get close to that 70 mark it gets a little more of a chore to work on these girls.

JHZR2 · #4 02-01-2023, 01:23 AM

Is the base idle still settable on those 606 engines? I know the 603 despite having electric control still has a base idle setting.

On my Dodge cummins, when I first got it, the idle was too low. It idled ok, but steering too much, IIRC in reverse without throttle, could stall it very easily. Bumping the base idle up helped a ton.

engatwork · #5 02-01-2023, 07:52 AM

How old is the crankshaft position sensor?

jake12tech · #6 02-02-2023, 11:49 PM

K40 or crank sensor.

treetops · #7 02-05-2023, 06:43 PM

X3 for crank sensor. No experience with K40, so cant comment, wiser heads than me here.

TX76513 · #8 02-27-2023, 03:52 PM

Quote:

Originally Posted by engatwork

How old is the crankshaft position sensor?

Replaced last in December of 2016 - I am suspect of CPS. and it's on the list. I did swap out with a known good K40 as I have a twin to this vehicle and the condition repeated in front of me.

When it stops it's just like someone turned the key off - identical. Now after 30 minutes, I can start the car again (like a CPS will allow you for a while). My experience tells me CPS doesn't produce a code for older girls.

I started to lean toward a fuel pump relay but haven't looked up the specs to test it. Poor excuse but this is one of my garage queens. Both parts of inexpensive but have never been one to just keep piling on parts to fix.

When testing the resistance on a CPS if the meter is 0.0 it's shorted. Obviously, this needs to be tested right after it fails while running right? Or is there a test resistance that states operational margins?

John

engatwork · #9 02-27-2023, 05:16 PM

Im assuming this is a 98 E300 turbodiesel? Dont waste your time looking for a fuel pump relay if it is

Diesel911 · #10 02-28-2023, 02:03 PM

Quote:

Originally Posted by TX76513

This one has me stumped so any random thoughts or ideas are acceptable

1999 300D Not a daily driver but frequent driver. Went to turn into driveway and the engine stopped just like you turn key off. Tried to restart several cycles and no go. Got tractor out and pulled into driveway and it started and ran for about 10 minutes and stopped again.
Things I looked at/checked/tested
No codes on my simple OBDII reader
Battery checks good with meter and load tested good.
No obvious wiring defects, unplugs, anything obvious out of order. Car is kept pretty tidy under hood.
Fuel Filters replaced in November 2022

I was hoping to catch a code to give me some where to start but nothing written or pending. It started right up this AM and was looking under hood when it shut down. Its just like someone turned the key off.

Thoughts, Ideas?
John

I am going to go with fuel filters.

I have seen a new fuel filter last not even an hour when the fuel is contaminated.

Another issue is your fuel supply lift pump and or the pressure relief/overflow valve.
The pressure relief/overflow valve some of the newer ones have some plastic spacer that warps or gets damaged.

tgemilwaukee · #11 03-01-2023, 12:18 PM

I had a 97 E300D that would act the same way. Random shutdown, and then would restart and run fine. Replacing the K40 Relay fixed mine. Never had the same problem again.

Cae808 · #12 03-01-2023, 06:20 PM

mine was the crank shaft sensor. On my 3 one now.

TX76513 · #13 05-06-2023, 04:35 PM

Quote:

Originally Posted by jake12tech

K40 or crank sensor.

That dude is 2 extensions down

What size T is that Bolt? What a POS place to mount.

chronometers · #14 05-07-2023, 02:28 PM

Any luck?

TX76513 · #15 06-03-2023, 10:10 PM

Quote:

Originally Posted by chronometers

Any luck?

Unfortunately No - did order the CPS from PP and finally grabbed some time and installed it. I ran it around for a few days (local) but then back to the original symptom of an engine turn-off.

Going to pull the K40 out and look at solder joints and anything suspicious. Fortunately, K40s are not that pricey anymore if I have to go that route. I had a spare but the PN is different.

This definitely is a head-shaker.