300D oil drain plug - PeachParts Mercedes-Benz Forum

R-3350 · #1 08-20-2015, 12:36 PM

hey i was wondering if anyone knows what the thread is on the pan drain plug. i am working on installing some instruments and wanted to replace it with a sensor.

mach4 · #2 08-20-2015, 01:02 PM

I'm assuming that you're looking to measure oil sump temperature. What I did was drill out the stock oil drain plug and insert a probe there. Since the cable is a pain I mounted it with magnets to enable removing the probe before taking out the plug to drain the oil. Here's a post on the design and fabrication.

Temp Sensor

And here's a link to my engine sensor project.

http://www.peachparts.com/shopforum/diesel-discussion/350205-engine-instrumentation-project.html

Keep us posted on your project.

R-3350 · #3 08-20-2015, 01:07 PM

i saw your thread looks good however im going for an entirely mechanical system. have a bunch of spare aircraft instrumentation im installing. EGT,MAP,oil temp,voltage,trans oil temp,and a real oil pressure gauge not the 3 bar thing thats in now.

leathermang · #4 08-20-2015, 01:10 PM

The bottom of the oil pan is sure subject to lots of things hitting it... like Armadillos..
I would consider side mounting.

mach4 · #5 08-20-2015, 01:18 PM

M12-1.5

R-3350 · #6 08-20-2015, 01:20 PM

the oil plug is parallel to the ground on the rear not pointing down

R-3350 · #7 08-20-2015, 01:20 PM

thanks thought thats what it was just couldn't confirm

leathermang · #8 08-20-2015, 01:24 PM

Quote:

Originally Posted by R-3350

the oil plug is parallel to the ground on the rear not pointing down

It is called ricochet... rocks or whatever hit something else and head towards that plug.... or the wires going to it...

mach4 · #9 08-20-2015, 01:42 PM

I agree that those that live in Armadillo-infested areas should consider moving their temperature sensor and drain plug up to the side of the pan...

R-3350 · #10 08-21-2015, 12:23 PM

i fabricated a skid plate to go over the oil pan and radiator. figured the stock ones are too hard to find and i value the intactness of my oil pan. still have to finish the mounts for it but that should keep the sensor safe.

Mxfrank · #11 08-21-2015, 06:59 PM

Should be m14x1.5

JHZR2 · #12 07-04-2016, 01:06 PM

So... Is it M14x1.5 or M12x1.5???

I see both mentioned in this thread. Im of the impression it is M12...

Thanks!

Dan Stokes · #13 07-04-2016, 02:20 PM

If no one else comes up with a definitive answer I'll pull the one on the spare engine and run down to the hardware and determine for sure which nut fits the plug. The hardware is not far from the house and that way I'll know absolutely and for sure both the diameter and thread pitch.

Dan

JHZR2 · #14 07-04-2016, 04:45 PM

I measured one, it is 12mm from edge to edge of the thread.