TTT -

Any word on if this fixed the problem? :)

Oil Warning Ligh
 

I have a 1987 300 SDL Turbo Diesel. Same problem. I drive for about 10 minutes, then the oil light comes on and usually stays on. The oil level is fine and the pressure and temperature is fine.

I do have an oill leak though, and I now believe I have a transmission leak.

I'll check the sensor area to see if the leak is coming from there. Sounds like I do need to change out the sensor. Can you let me know how you replaced it and where to purchase a new one.

Thanks

David

Yes, I replaced the whole sensor because the sensor was actually leaking from the part where the plastic goes through the aluminum body. The o-ring that sealed the sensor to the oil pan was not leaking. You may want to clean everything up real well and see if you can tell if it's the actual sensor that's leaking, or the o-ring to pan seal. If it's just the o-ring then I would think you could get away with just replacing the o-ring.

There are two bolts that attach the sensor to the pan, it's on the driver side. It just looks like a round piece of aluminum with a sensor in the middle, on the inside of the pan there is an aluminum body that contains a little float level (I think it's a float) but you won't see that part until you take the whole thing out of the pan. All you have to do is disconnect the wire, undo the bolts and it's out, just a couple of minutes of work, you'll have to move the sensor into various positions to get it through the hole in the pan.

I got my sensor from S&G which is a local import shop, and it didn't come with the o-ring to seal the new one to the pan so check on that when you're ordering yours.

As for the transmission; clean it up real good with Simple Green or similar, then wait a few hours, go back underneath and check out all the potential leak areas. I found that my dipstick o-ring is leaking and my kickdown cable is leaking. I suspect that the front seal may also leak because this car spent alot of time just sitting which puts uneven pressure on that seal. I haven't fixed any of the tranny leaks yet but it looks like it's going to be a challenge.

I have to go pick mine up when I feel like driving for a bit. It's just far away. :o

I'm tired of that light after some driving and the leak associated with it.

My '98 also needed this part.
 

It's good to know that well into the 90's these were still troublesome. I also had a leak through the sensor on my '98 E300 and just replaced it ($50 for the part from the dealer). It wasn't a serious leak, just a drip but the low oil warning did start to come on despite it being full...since I replaced it no more leaks and no more warnings.

oil leak and light comes on
 

mines leaks there and the light comes on when Im on the freeway and taking big turns......my dip stick shows level at about 1/4 inch below max!
I assumed it was that sensitive while at high RPMs and lowering the level in the pan to trigger the light!

I will be getting a new sensor and the o ring!

AlanT

Mesa Az

86 SDL

There are two o-rings, be sure to pick up both.

I have a leaking power steering pump (return lines used to leak like mad, $11 fix there) currently as well as an IP that leaks oil :(

This sender is one of the larger leaks I have, so I'm hoping the IP fix isn't too hardcore. I may reseal it at the same time I do the RIV tool deal.

I have a 1986 300sdl and my sensor was leaking also from the sender itself, not the rubber seal. I just purchased a new sensor and mine came with the o ring. I did this at oil change time and it took a whole 5 minutes to do. It has been three months now and no leak.

John

Any significant amount of oil come out?

A faulty design easily fixed forever....
 

Hello All,

I also have the same sender leak (from the middle not the o ring) and purchased a new unit for replacement and studied it for a while. The problem is a design flaw in manufacturing. The sender itself is inserted through the alum housing and fixed by four bent over mounting tabs. This is a poor design for sealing because as the plastic sender body goes through normal heat cycles it will shrink and thus loose its seal and cause the leak. The sender usually will long outlast the sealing abilities of the mounting design.

So a dab of JB Weld or your favorite epoxy around the sender mounting area in the external part of the housing will create a much stronger and leak proof design. Although my current sender has 220k mi it functions properly just leaking. My new one will go in and it has already been JB welded, and my old one will come out be fixed and become a spare.

Hope that helps others end this leaking issue once and for all.

I think you have figured out the leaking issue but I may be able to help about the warning light. Unfortunately this is not an easy fix. I had the same warning light problem you all have had. What happens is that when the engine is relatively cold the oil level will drop in the pan because the oil tends to flow back into the pan more slowly, ultimately causing the sensor to trip. When the oil is hot, it will slop around more and can trip the sensor when you go around long fast turns (ever notice how it tends to happen on long, fast left turns...that's because the oil flows around the baffles to the right side of the pan causing the sensor to get an artifically low reading) or are on steep hills. MBZ knew this would happen so they added a circuit that would delay the warning lamp and only trip if the sensor was actually reading low for more than a few seconds (I'm not sure what the actual delay was). The bad news is that the delay circuit frequently packs it in and is located in the instrument panel so is not easy to replace. I found a new fuel/oil pressure/temp gauge assembly on Ebay which solved the problem (mostly). The warning will still go on if I park the car with the driver's side elevated and occasionally when the oil is cold, but seldom goes on in normal driving. You can take your chances with a new/used gauge cluster like I did but since this is a fairly common problem don't count on a used replacement working any better. I got lucky as I was having problems with my fuel gauge and was surprised when my replacement fixed the warning light too. Maybe someone really good out there could devise a plug in delay circuit that could be retrofitted.

not alowing mine to get to me 86 SDL
 

My warning light also comes on while on the freeway!
My sensor leaks enough to leave a little drip on the garage floor!
I have decided that it IS an "IDIOT LIGHT" and most of us on this list ARE NOT IDIOTS!
If it EVER comes on when I fire her up then I guess that would promp me to check the level~ and at that point be usefull!
I did notice that if I keep the oil at the absolute FULL mark~~it comes on less!

MY 2 CENTS WORTH