Burn the Old Engine Oil? - Page 3 - PeachParts Mercedes-Benz Forum

R Leo · #31 06-15-2004, 05:53 PM

My 300D's fuel mileage varies greatly; sometimes it is at 21mpg, the next time it's at 26. Since the driving style fundamentally never changes and my odometer had been accurate every time I've checked it, the only thing left to a variable must be the cetane rating of the fuel.

oldnavy · #32 06-15-2004, 06:14 PM

Most diesel drivers do not realize the effect of the quality an cetane rating of their fuel.

My wifes VW TDI has a 130 mph top end with 50 cetane PowerBlend from a AMACO station 50 miles from us. Running the local in BP Supreme in town that's only 42 cetane the car will only hit 108 mph going down hill. With B100 it tops out about 121 mph. All speeds are GPS speeds, not speedometer. And I won't mention the difference in fuel mileage.

Lots of stations that work on cars and sell both gas & diesel will dump their waste oil in the diesel tanks. I have seen this being done on several ocassions in the past 45 years.

RVR · #33 05-24-2005, 03:02 PM

Listmembers,

Used crank case oil is *used oil*. I ran a filtered 50/50 ratio through
my 79 240D.

Result: In about 3 weeks, it became more & more difficult to start;
then, it would not start at all.

Reason: The micron size particulate suspended in the waste oil
eroded the bores of the FI pump, rendering it useless.

I know, that the economics are appealing to run old lube oil, but the price of
a used FIP (read: $ 250.00) pump would *more* than pay for what I *saved*.

Wishing you well with whatever your choice may be re. this old oil issue.

RR
OKC/OK

71 220D 357K
81 300SD 280K
79 240D (donated to charity after too many "issues")

R Leo · #34 05-24-2005, 04:28 PM

Why didn't the stock fuel filters stop those particles?

blueranger · #35 05-24-2005, 11:10 PM

when i change my oil once ever month or two i pour it into the
tank and drive away happy... i fill my tank with diesel and there
is no problem...

2 gals of oil to 15 gals diesel... once ever 3000 miles.

TwitchKitty · #36 05-25-2005, 08:29 AM

Quote:

Originally Posted by RVR

Listmembers,

Result: In about 3 weeks, it became more & more difficult to start;
then, it would not start at all.

Reason: The micron size particulate suspended in the waste oil
eroded the bores of the FI pump, rendering it useless.

How did you determine that this was the reason?

sailor15015 · #37 05-25-2005, 10:24 AM

Mine actually runs better on veggie. The only time it runs rough on veggie at idle speed is when I have a clogged filter or have just changed one and there's air in the system. What about running synthetic oil instead of petrol? Would that make any difference. I don't think I'll be running my Mobil 1 5W-40 through my engine anytime soon. Just curious.
Thanks

P.E.Haiges · #38 05-25-2005, 10:05 PM

Sailor,

No difference in burning synthetic oil. Its all oil the stuff Diesels are made to burn.

P E H

rg2098 · #39 05-25-2005, 11:08 PM

I know some of you are going to yell at me for it, but I'm running 75% used filtered motor oil and 25% used filtered ATF. Loads of power, bit of smoke, rough idle, but smooths out quickly. Best of all ITS ALL FREE!!

TwitchKitty · #40 05-26-2005, 01:10 PM

Quote:

Originally Posted by rg2098

I know some of you are going to yell at me for it, but I'm running 75% used filtered motor oil and 25% used filtered ATF. Loads of power, bit of smoke, rough idle, but smooths out quickly. Best of all ITS ALL FREE!!

Is this a one-time thing or a continuing practice? Mine clogs up when I have tried even 50% Waste engine oil and 50% regular unleaded. I prefilter the oil through a 1 micron bag filter.

RVR · #41 05-26-2005, 02:35 PM

Using a 50/50 mix, i did experience a *higher* coolant temp maybe 10-20F
(just guessing). It was clear, that the temp gauge indicated higher coolant temp (maybe two needle-widths max). The engine did not idle well at all..
it wanted to stop, and it did stop a few times and was very difficult to re-start. It did smoke much more as well. In retrospect, maybe a 75/25 diesel to used oil mix would have been better. At that time, however, I was just experimenting. It seemed as if the 50/50 idea was a good starting point.

All was in the name of fun and i learned a lot. Just recd an email from a guy that mentioned that there was a possibility of water entrained in the oil.
He was right, bcs water is the "kiss-of-death" to FI pumps & injectors. The
OEM in-line fuel filters on our MBZ's are supposed to filter out this stuff or so i thought. So what if a filter gets plugged. Big deal!

What type of 1 micron bag/filter do you speak of?? Where are they available?
Pls advise. Are you currently running usd oil/fresh diesel mix? If so, hope you have much better luck than i did.
TIA
Ron Rueb
OKC

R Leo · #42 05-26-2005, 03:16 PM

The final filters on the 616 and 617 are useless for stopping any entrained water and only marginally effective at stopping free water. In addition, there's no warning devices to let you know if/when you have collected water in a filter.

Old300D · #43 05-26-2005, 03:58 PM

Quote:

Originally Posted by RVR

Using a 50/50 mix, i did experience a *higher* coolant temp maybe 10-20F
(just guessing). It was clear, that the temp gauge indicated higher coolant temp (maybe two needle-widths max). The engine did not idle well at all..
it wanted to stop, and it did stop a few times and was very difficult to re-start. It did smoke much more as well. In retrospect, maybe a 75/25 diesel to used oil mix would have been better. At that time, however, I was just experimenting. It seemed as if the 50/50 idea was a good starting point.

All was in the name of fun and i learned a lot. Just recd an email from a guy that mentioned that there was a possibility of water entrained in the oil.
He was right, bcs water is the "kiss-of-death" to FI pumps & injectors. The
OEM in-line fuel filters on our MBZ's are supposed to filter out this stuff or so i thought. So what if a filter gets plugged. Big deal!
...
Ron Rueb
OKC

If the stuff is plugging your factory filters, I would be concerned about the abrasive particles getting to your injection pump. It's been previously stated that harmful particles as small as 7 microns can prematurely wear the pump, and the factory filters will pass particles that small. The 1 micron bags are cheap, about $3 at www.mcmaster.com

TwitchKitty · #44 05-27-2005, 09:23 AM

I am using filter bags like the ones mentioned by Old300D in the post above. I bought my last batch from filterbag.com. I use them for veg-oil.

I do have a 1/2 tank 50-50 batch of waste motor oil in my tank right now and I will drain it today. I want to take the car out of town and haven't had the success that would encourage me to leave town with the mix in my tank.

I have experienced much of what is described here, higher coolant temps, slower idle, ugly exhaust smell, slow starts and some hard starts, frequent clogged filters, good power until the filters clog.

The attraction of used motor oil is that it is readily available and flows better than veg. I have not had pleasant experiences attempting to run it as fuel.

TonyFromWestOz · #45 05-27-2005, 09:03 PM

I use Used Diesel engine oil in my 300D. I filter it thru a cheap inline filter and mix at a 10% blend with either Used Cooking Oil (UCO), or biodiesel.
I have had no issues with exhaust smell or any running issues.

From my experience, the above problems relate to the high concentration of oil in the fuel. Blend it down to reduce or eliminate the issues which bother you.

I am burning the crankcase oil from 3 vehicles in my 300D, with NO problems.