1999 E300 TurboDiesel Code P0380 - PeachParts Mercedes-Benz Forum

EDBSO · #1 06-01-2013, 04:36 PM

Well road trip time and made NYC nicely now at the Greenwich Concourse d' Elegance.

North American metal today, tomorrow the imports. However I did see what is reported to be the only surviving E300 wagon. Photos to follow.

Before leaving the glow plug light had been flashing on and off after the Indie replaced the oil cooler and hoses. No previous problems. Related or coincidence?

Now I have check engine light and glow plug light on continuously. I always travel with my code reader and In have P0380 which indicates glow plug problems. Will check resistance of the plugs upon return home.

Anything else I should be looking at?

PS, glow plugs are about 2 year old Bosch, will have to confirm exact date from maintenance log.

TMAllison · #2 06-01-2013, 07:11 PM

Most common PO380 is when key is turned w/o waiting for GP lite to go off first. Resets after 3 hot/cold run cycles. Can also indicate relay didn't come on.

EDBSO · #3 06-01-2013, 08:14 PM

Thanks TMAllison;

Give that the glow plugs are reasonably "new" a relay could be the prime suspect.
Can you help with a location and part number?

ouch, thought that I might replace as preventative maintenance but perhaps not?
I'll have to do some testing Monday

jay_bob · #4 06-01-2013, 08:47 PM

Yup, BTDT

My wife did that after she had been driving it about a week. This was her first time driving a Diesel. Poor thing, she calls me in a panic asking if she broke the car.

Pulled the code and reset it. No worries.

EDBSO · #5 06-02-2013, 08:27 AM

Just did a cold start after sitting over night and while it fired right up it ran rough for a few seconds till the temperature in a cylinder or two reached temperature and it ran smoothly on all cylinders. I will be very surprised if I do not have a bad glow plug or two.

TMAllison · #6 06-02-2013, 12:01 PM

I would clear the code if it was mine and see if it comes back on the next start. Sounds like it will from your lumpy start description. I'd then test it. If you have bad GP's, a better scanner would pull up codes P1365, 66, 67 indicating cyl's 1/2, 3/4 & 5/6 respectively.

The relay is located on the drivers side fenderwell aft of the windsheild washer bottle.

EDBSO · #7 06-02-2013, 07:30 PM

Home safely and I have one open resistance glow plug.

I know that I have read that the pins are numbered but even with a very bright light and an eagle eyed wife we can not find any numbers.
Please where should we be looking for the numbers, thanks

KarTek · #8 06-02-2013, 07:56 PM

OK, I went out and looked at mine and the numbers are on the back of the connector. If you unplug the connector and look at the face of it where it plugs into the relay, the wires are numbered like this:

1-3-5
2-4-6

I found one of my old pictures. In this shot, number 1 is the upper right.

EDBSO · #9 06-02-2013, 08:20 PM

Thank you KarTek, actually also found the numbers on the back of the plug.

and the winner is #5

Too bad it is so far under the intake manifold. I would like to test from the glow plug directly to eliminate the wiring harness.

last replaced March 2011

How does the wiring harness disconnect from the glow plug.

Thanks

KarTek · #10 06-02-2013, 09:03 PM

If you look at the top of the glow plug, there's a straight section and a collar about 1/2" down. Originally, the connector had a plastic housing that fit down over the terminal and snapped onto the collar. If yours is like mine, all of the plastic connectors have become brittle and the part that snaps to the collar is broken off. So, the connectors are holding on simply by the friction of the metal contact inside the connector. This is not a problem for the most part but I've accidentally knocked one off with the blast from a pressure washer. It's also entirely likely that #5 was loosened from some contact during the oil cooler service.

EDBSO · #11 06-03-2013, 05:19 PM

I removed the transmission (beauty protective) panel and from underneath I could see that the wire looked attached. Couldn't get near it with my hand but with a piece of wood was able to push down on it and still the problem persists.

I'll have to remove the manifold to test the continuity of the wire and the glow plug completely.

Are Beru considered to be a better, higher quality glow plug?

10 to 15 degrees cooler today and it took a longer time to get heat into the cylinder before it would run smoothly.

TMAllison · #12 06-03-2013, 05:41 PM

The Beru GP has a slightly longer nut section than the Bosch plug does. Beru was also OEM.

When I had a bad GP, I found if I quickly slipped it into reverse, backed out of the garage and then put it back into park that the lumpy idle almost always disappeared within a few seconds. If I allowed it to idle in the garage, the lumpy idle lasted 15 - 20 secs before it began to even out. Have no idea why.....worth a try.

EDBSO · #13 06-09-2013, 12:45 PM

s promised a 1957 Mercedes Wagon a custom order 1 of 1 car.

EDBSO · #14 06-13-2013, 09:45 PM

Update on #5 glow plug . . .

So I did the Red Green fix and covered the glow plug light and check engine light with a piece of black tape, and I have been living with the rough starts first thing in the morning.

3 mornings ago it glows and starts up smooth and normal. Later in the day I check the resistance of pin 5 to ground and it to is normal. It has been running normally and starting smoothly for 3 days.

Can anyone tell me if the wire goes directly from pin 5 to the glow plug or whether it rums through something else along the way.

Can't reach the glow plug connector but did push on it much earlier with a piece of wood and it appears secure.

I have reset the code and removed the tape.

engatwork · #15 06-14-2013, 05:54 AM

Wire should go from relay to plug.