I have an odd problem and I have a feeling someone on here can point me in the right direction. My AC blows pretty cold, but with the AC on the car seriously drags ass. The second I turn it off my acceleration improves very dramatically and vice versa. In addition to this, on long drives or in heavy traffic the engine gets very warm with the AC on (110). Ive already flushed the radiator, changed the thermostat and checked the fan clutch. I dont know where next to check. Is it perhaps the drive belt being too tight?

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1983 300SD White with Grey interior

That is typical. My '82 is the same way, but only when accelerating from a dead stop. Once the turbo spools up, it is not bad.

The A/C compressor is a horsepower hog and saps the engine pretty good.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

How tight is it?

R 12? 134? proper charge? clean alda hose banjos? is this just at a light? or is this all the time? 120HP drops down by 10 or so with the a/c on. also the RPM is limited by the a/c, so hard acceleration is cut down considerably.

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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!

The problem is entireley centred around early acceleration. As someone else had mentioned, once the turbo kicks it's not as much of a problem. I only found it weird because my previous SD did not really have this problem (despite the fact that the engine was in a much rougher condition). I am going to adjust the valves this weekend, do a purge and see if that helps anything.

Any ideas on the temp issue?

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1983 300SD White with Grey interior

I guess if you're only starting off with 120hp, 10HP would be pretty noticeable, close to 10%. Is the HP drag fairly consistent on other models with more HP?

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" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

this is normal, the ac systems on these cars are poorly designed.
make sure your aux. fan is kicking in when the temp goes up

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82' 300SD

Actually, the best you get is about 85hp at the rear wheels. Below 2500 rpm, I'll bet you've got about 35hp at the rear wheels. The a/c probably saps about 6 hp at lower rpm's.........still a massive loss in percentage terms.

Yes, I have trouble understanding the appeal of the 240's for this reason.

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" We have nothing to fear but the main stream media itself . . . ."- Adapted from Franklin D Roosevelt for the 21st century

OBK #55

1998 Lincoln Continental - Sold
Max 1984 300TD 285,000 miles - Sold
The Dee8gonator 1987 560SEC 196,000 miles - Sold
Orgasmatron - 2006 CLS500 90,000 miles
2002 C320 Wagon 122,000 miles
2016 AMG GTS 12,000 miles

My 83 300SD behaves the same way with the AC on, although I rarely test its performance with the AC off. I almost always have it on because the heat is too unbearable around here, and when I drive in city traffic the coolant temp reads about 105C to 109C. I get about 5 to 10 degrees lower on the highway. And yes, it drags.

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1983 300SD (W126, OM617) with 404k miles!
(OK, so the engine was replaced at 147k mi)

When I had working A/C in my 240 I would have to place the accelerator pedal on the floor and feather the clutch to get the car rolling.

Scott

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Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

My 84 300SD acts the same way. It's a dog starting off with the A/C on. Throw in a road incline and it's almost unbearable. It's times like that where I temporarily turn off my A/C until I get up to speed. I also turn it off when I pass slower folks on the two lane country roads around here.

I guess you would say the A/C Off button is a "boost" button.

.....Dan

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99 e300
98 e300
90 Suburban 1500 4x4
92 ZR-1
04 Tahoe 4x4
05 Scag 52" zero turn
97 e300 - totaled on black ice
84 300SD - gave to a friend
85 300TDT Euro - SOLD to my little bro