SO i just got a tiny tach installed in my 83 240D .
how fast is the engine supposed to be running @ 70 mph ?

the tach is showing 3700 rpm and yes it seems like the transmission is going through all 4 gears ..

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current fleet
Ford f350 dully 7.3L 1990 . ats turbo , zf5
Mazda 4x4 b2600 with 617 20-26 mpg
Past fleet
1983 240D w123 232k 25-30 MPG
1984 Ford f250,1979 ford 150 300-6 (sold@ 251K )
81 300D, 79 240D , 2x 76 300D ,74 240D , 2x 89 grand prix , 85 grand fury , and several other fords

Custom machine shop work ..

I don't know the number, but that sounds about right. Mine really starts screaming if I get much above 65mph.

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These cars were designed when the national 55mph speed limit was in effect.

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Sam

84 300SD 350K+ miles ( Blue Belle )

Sounds about right.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

A 3.69:1 axle with a P205/70R14 would yield about 3500 @ 70mph...

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

Ok ...

so what is the MAX safe rpm ?

i know one of my engines says 64HP @ 4K rpm
so im guessing 4k ?

__________________
current fleet
Ford f350 dully 7.3L 1990 . ats turbo , zf5
Mazda 4x4 b2600 with 617 20-26 mpg
Past fleet
1983 240D w123 232k 25-30 MPG
1984 Ford f250,1979 ford 150 300-6 (sold@ 251K )
81 300D, 79 240D , 2x 76 300D ,74 240D , 2x 89 grand prix , 85 grand fury , and several other fords

Custom machine shop work ..

If you keep your car / engine well maintained I say you should be quite safe to get very close to max chat so long as you have the engine under load. So don't rev the crap out of it in neutral.

For old cars I reckon it is more of a case of "use it or loose it" rather than wrap it up in cotton wool.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

The governor will prevent overspeeding, but for cruising better not go over 4400 rpm (rpm of highest power), even if the governor will allow higher speeds. Early diesel tachometers had red lines at 4500–4600 rpm.

Under no-load condition, the maximum speed for a USA-240D is 4700–5200 rpm, depending on how the IP was calibrated.

X2. Good post...

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Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership

Ok ...
that just seems really fast for a diesel .. lol

most diesels redline @ 3500 or less

__________________
current fleet
Ford f350 dully 7.3L 1990 . ats turbo , zf5
Mazda 4x4 b2600 with 617 20-26 mpg
Past fleet
1983 240D w123 232k 25-30 MPG
1984 Ford f250,1979 ford 150 300-6 (sold@ 251K )
81 300D, 79 240D , 2x 76 300D ,74 240D , 2x 89 grand prix , 85 grand fury , and several other fords

Custom machine shop work ..

IDI from MB gives you a much higher rev than the typical truck/tractor motor.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

And keep in mind that diesel engines are especially well suited to running at close to or full load/RPM for long periods of time. Think - diesel generators.

Interesting post. I feel like my 90 SDL is done @ 80 mph (4K)....max! It's soooo much happier making boost @ 2K-3K.

Not to hijack this thread, (and in the interest of "am I doing this right") but I had an old timer tell me that "back in the day", there were so many fewer traffic lights. He said to put the car in neutral at stop lights. I recently had a '65 Buick which I got in the habit of putting in neutral at lights, for which I tend to do that with the Benz now.

So rather than leaving the tranny loaded up in "D", foot on the brake, I shift into neutral until it's green.....

Thoughts on that?

PK

That's fine, so long as you don't wind it up before it's back in gear.

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

Speed of engine is limited because of the injection pump I once read somewhere. The noise is bothersome to some as well at 70 mph in a 240d. I doubt it is hurting the engine at all.

Except piston speeds are also high. The 240 tends to burn somewhat more oil towards the top rpms. So check your oil level more often when on the highway a lot. In my limited experiences some 240ds are louder or quieter than others at higher speeds. I have yet to ride in one at speed that you are not aware it is humming.