Hi Roy,

What should the tach read on an 80k mile '83 300SD at 65mph?

I know deisel are supposed to smoke but should i see smoke at that speed? I feel that my SD smokes a little too much. Adjustment to valves was done 4k miles ago and this cut down the amount of smoke, new ALDA also aided, but still can see smoke trailing off as I drive, it is deisel smoke as opposed to oil and the car has not leaks.


Also thanks for the help on the water in the trunk. it is the trunk seal as diagnosed.


brgds,
Rafael

for mine at that speed its almost 3000 rpm

__________________
198? 300D ???K - Future DD
1989 300TE 285K - traded in '12
1984 300SD 186K - Sold in 08
1978 300SD 330K - Died in 05

How many total miles on the car, I can't recall.

Check for leaks in your vacuum system = all air sucked from there goes into the crankcase = adds pressure = blows more oil to the intake oil separator = more smoke.

I am glad the trunk seal stopped your leak.


Have a great day.

__________________
ASE Master Mechanic
asemastermechanic@juno.com

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
Vehicle build.
Fleet Durability
Technical Quality Auditor.
Automotive Technical Writer

1985 300SD
1983 300D
1984 190D
2003 Volvo V70
2002 Honda Civic

https://www.boldegoist.com/

It could be several things

Fouled injectors cause poor combustion. Dump a half quart of ATF in your next full tank and/or run some Power Service.

Low boost. Check for boost leaks. The plastic ALDA line ends inperticular.

Check for a stuck open EGR valve. As EGR increases so does diesel smoke.

My car does 65 at around 2500 rpm however mine is an 85 with a 2.88 rear end instead of the 3.07.

__________________
green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

My SD is at about 2700 at an honest (GPS corrected) 65. I am running oversized tires.

With the stock tires, it showed about 2750 to 2800 at an indicated 65, but I was really only going about 60. So I guess in stock form I was real close to 3000 at an honest 65.

__________________
2009 VW TDI Jetta Sportwagon 172k miles (rear-ended harder than Elton John on 8/4/13. Total loss)

1991 Volvo 240 142k miles (T-boned by a stop sign runner. Total loss)

Not sure what size tires you have, but here's the formula:

MPH X RATIO X 336 = RPM
TIRE DIAMETER

__________________
82 300SD 202K
82 300SD 233K
83 300TD 340K
82 300TD 98k euro (parts on the hoof)
85 300TD 282K
83 300TD 197K

http://www.miata.net/garage/tirecalc.html

Just under 3000 rpm on the SD. New ALDA should not need adjusting, but you never know,

__________________
83 SD

84 CD