Oil change question - PeachParts Mercedes-Benz Forum

ajcbgray · #1 05-06-2008, 12:48 PM

I just changed the oil in my 300d for the first time and was astounded by how black the oil was. Now, I haven't had any experience with diesels and I suspect this in totally normal, but I wanted to make sure. The oil had 3,000 miles on it and it felt clean and slippery (normal in other words) between my fingers.
thanks,
ben

#2 05-06-2008, 12:54 PM

Perfectly normal, if you look at the dipstick you will find the oil is very black after the first few miles.

SD Blue · #3 05-06-2008, 12:54 PM

Very normal due to soot that a diesel engine produces. Just ensure that you use a diesel-rated oil (noted by a "C-rating" on the container) which has an additive to aid in suspension of the soot particles.

1985300d · #4 05-06-2008, 01:03 PM

make sure you check\replace the 2 rubber o-rings at the bottom of the filter lid shaft

mine were so bad, very hard, i had to use a knife, they chipped away like a rock

if they are old, they shrink and it wont seal the dirty oil from the fresh filtered

new oil will turn black very quickly, its normal

i saw a filter for big diesel trucks, the filtered oil looked gold new!

ajcbgray · #5 05-06-2008, 10:57 PM

Thanks, just wanted to make sure.
I didn't get the o-rings with my filter, but the ones on the shaft seemed OK... should they come with the filter?

pawoSD · #6 05-06-2008, 11:17 PM

Quote:

Originally Posted by ajcbgray

Thanks, just wanted to make sure.
I didn't get the o-rings with my filter, but the ones on the shaft seemed OK... should they come with the filter?

No you have to order them separately....sometimes the filters don't even include the copper crush washer. I've bought a bunch of spares of both so I never have to worry about it.

Diesel911 · #7 05-07-2008, 12:47 AM

The new oil is going to start to get black again much faster than you would expect too. Some diesel engines get the oil blacker faster than other makes do.

barry123400 · #8 05-07-2008, 12:55 AM

As the guys mentioned it is normal and a reminder it is soot contaminated. The oil changes on these indirect injection diesels should never be delayed. As the soot accumulates it can clump together and becomes abrasive in nature. If you change at the prescribed intervals the soot level will be safely within guidlines.

ajcbgray · #9 05-07-2008, 07:59 AM

as for those crush washers.... there were none installed in my car when I removed the old filter and I didn't see any place one would fit. Are they just for other models or did I miss something?

vstech · #10 05-07-2008, 08:22 AM

the crush washer goes on the oil drain plug bolt

Dee8go · #11 05-07-2008, 08:26 AM

Quote:

Originally Posted by pawoSD

No you have to order them separately....sometimes the filters don't even include the copper crush washer. I've bought a bunch of spares of both so I never have to worry about it.

I bought an oil filter recently for my 300TD. It's just the element. I've never had one like this before. This is my first diesel. Do all of these require that you have to replace the crush washer and O rings each time, or just certain models?

LUVMBDiesels · #12 05-07-2008, 09:39 AM

Quote:

Originally Posted by Dee8go

I bought an oil filter recently for my 300TD. It's just the element. I've never had one like this before. This is my first diesel. Do all of these require that you have to replace the crush washer and O rings each time, or just certain models?

I replace the large O ring on the filter cover each time. I usually do not replace the crush washer on the oil drain plug (I keep forgetting to do that) but it never leaks soI don't worry about it. The o rings being talked about are the two small ones on the filter shaft. These should be replaced every couple years as they do get brittle and hard. I did them once on the 300SD and will do them at the next oil change on the SDL.

One way to tell that they are going bad is that the pressure needle in the gauge will bounce rapidly when you idle the engine after wariming it up and driving it a while.

Diesel911 · #13 05-07-2008, 10:21 AM

Look at some of the internet part sellers and they will sell "Oil Filter" and "Oil Filter Kit". The Oil filter kit comes with the large O-ring for the filter cap and the Crush Washers for the Oil Pan Drain Plug.
For some reason the 2 Oil Filter Cap Stem O-rings do not normally come with the kit.
They are ordered separately but you end up with 2 that are the same size; which is what I have uesd. I have part of a quote that I copied from one of the members but do not know which thread it came from.
"For some reason the 2 Oil Filter Cap Stem O-rings do not normally come with the kit.First thing is to put the correct "O" rings on the filter head stem, (no, they are not the same, the lower one as installed is 6mm x 10mm, and the upper is 7mm x 11mm. Don't believe it, take a dial caliper and measure the stem)."
I do not always change the large cap O-ring or the drain plug washer if I am in a hurry to get the job overwith.
Also for some reason I have seen the price of the bare filter to be more than the Filter kit with the O-rings. In any event I always buy the Oil Filter Kit.
It is well worth your time do do some internet searches on the price of oil filters and buy several at a time which saves on the shipping cost. Some of the internet parts places have free UPS ground shipping if you spend more than a certain amount of money with some it is around $50 with others it is more.

bobodaclown · #14 05-07-2008, 10:32 AM

Quote:

Originally Posted by LUVMBDiesels

One way to tell that they are going bad is that the pressure needle in the gauge will bounce rapidly when you idle the engine after warming it up and driving it a while.

Nice info to know.

Dee8go · #15 05-07-2008, 10:53 AM

So, if you pump your oil out through the dipstick tube, you wouldn't have to worry about the oilpan plug anyhow. I'm thinking of doing mine this way from now on.

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