cold weather and odd reactions with my SD - PeachParts Mercedes-Benz Forum

greasybenz · #1 12-04-2006, 12:53 AM

Last tuesday South San Francisco was near freezing, i live on a hill so it was freezing

. I was worried for morning because my SD was at 1/4 fuel level and it was B100! So i cycle the glow plugs longer and start it, it stumbled, shook, rattled but it was running.

So off i went to work. Im low on bio (need to re-order some) so i filled up on ULSD at chevron. And i started noticing after a longish drive my car idles like it has low compression on some cylinders but runs just fine when moving. Today i filled up at the biofuel oasis in berkley on my up to vallejo to pick up a friends car. On bio i noticed the car idles normally and not like its low on compression. And still runs just fine.

Why is this? Im due for valve adjsutments and have been putting it off as ive been way to busy to do it but could this be a cause? If so why does it idle weird on ULSD and not on bio?

Bruce Kennedy · #2 12-04-2006, 01:07 AM

Define weird. I have noticed that my cars run quieter on biodeisel. I beleive this is due to the higher lubricity. I havent noticed any power difference, just a difference in there sound.

85 300td
85 300d
84 300sd
83 300d
81 240d

greasybenz · #3 12-04-2006, 02:25 AM

the quietness isnt the weird part. Its the low compression sound and the shaking my engine does when on ULSD.

my 603 is defenitally quieter on bio and its noticable the second you fill up on bio after running a tankfull of diesel.

But thats not my concern, its the low compression sound that makes me worry. Maybe i should make a video file in comparison to explain more.