82 300SD-Is it really this much of a dog?

Until then, it has nothing! Did Daimler Benz actually design this car to be this much of a dog off the line? I don't want to floor it each time I start off so it will kickdown to first gear and actually have some power. What can I do to improve the power from 0 to 20? Or. . . do I learn to live with it? Like I said, I love this car and if I have to, I'll just drive like I'm 80 years old. But any thoughts on this will be sincerely appreciated.

A friend has an '83 SD (super dog) and it too is quite sluggish. I b'lieve the torque converter is the culprit. The stall speed is waay to low. I don't know if the conveter from a 123 TDT would fit but it would be worth investigating.

Chas Hurst

Until then, it has nothing! Did Daimler Benz actually design this car to be this much of a dog off the line? I don't want to floor it each time I start off so it will kickdown to first gear and actually have some power. What can I do to improve the power from 0 to 20? Or. . . do I learn to live with it? Like I said, I love this car and if I have to, I'll just drive like I'm 80 years old. But any thoughts on this will be sincerely appreciated.

Yep, it's a dog from dead stop, but once it hits 80, it wants to keep on running (I found myself doing 90-95 across I-8 in Arizona without any effort).

HINT: any vacuum leaks will make things worse, so check your hoses/clamps and replace them as necessary. TG taught me that trick early on.

then, it has

the line? I

and actually have

I'm 80 years old. But

Definitely something wrong with it. I had a '85, people couldn't believe that a diesel car, and of that size, could accelerate so fast.

cp

My 82 300D always starts in first gear . I think your SD also starts in first. You should be pulling great off the line. If I floor mine off the line, it will chirp the tires when it catches second. Check vacuum for leaks. Also check the kick-down adjustment cable on the top of the valve cover. Those get tinkered with and mess up the shift pattern.

Larry In the back yard, under the oak.

Wow! I couldn't have asked for a wider range of replies. My 300SD does shoot off the line if I floor it, because it kicks down to a lower gear than it normally starts off in. But with normal starts, it doesn't anywhere in my wildest imaginings compare to any gas powered car I've ever had. But now that I have it, I promise to love, cherish, and tinker with it until death do us part. (oops, still got some of that Valentine's Day bug in me).

Thanks for all the great answers, guys! Rob

This transmission has FOUR forward gears. At idle, while you hold the car with the brakes it idles in 2nd to prevent creeping. After you release the brake and when you step on the accelerator it automatically and almost imperceptibly, downshifts into 1st gear. That's not happening in your car.

When it's at a full stop you can shift into L. The transmission will start off in 1st gear. Then upshift to S and immediately back to L and it will be in 2nd gear. Upshift to S (and leave it) for 3rd gear and upshift to D fro drive.

Back to the problem.

Do you brake with your left foot and drag the brakes by not fully removing your foot? That will cause the brake lights to remain ON and prevent the transmission from downshifting into 1st gear.

Otherwise, check fuse #4. Check transmission pressure switch (right side at rear); it should be OPEN at idle with transmission in D and close to GROUND above 5 MPH.

Great! I'll take a look at that first. Now then, on to other concerns. Please keep in mind this is the first MB I've ever had (or come in actual contact with now that I think about it) so you might have to speak to me like I'm a four year old. When I test drove this car, the oil pressure gauge bounced around all over the scale. Now when I started it today, it pegged out at the top and stayed there. Big problem or bad sensor? I think my first action should be all maintenance service including valve adjustments. I don't think the last owner showed this car the TLC it deserves.

The oil pressure may still be a mechanical gauge - a pipe from the oil filter base to the gauge. What sometimes happens is that a couple of old, old, hard "O" rings inside the oil filter canister allow oil to bypass the filter erratically which makes the gauge buzz and vibrate at idle. These "O" rings ought to be replaced at the next oil change; the "O" rings are available from the dealer. There's no other reason for the gauge to "bounce around" it should read about 1.5 BAR at hot idle and 3 BAR above, say, 1,200 rpm. BAR = one atmosphere, 14.7 lbs.

Adjust its valves and, while its open, measure the timing chain's stretch, clean out the "banjo fitting" a fitting and hollow bolt attached to the very aft end of the intake manifold, replace the two fuel filters and engine air filter, replace the transmission fluid and filter. Do these things and it's good for 15K miles when the valves need an adjustment and another 15K miles for the other items.

Thank you very much, T. G.

I may be relying on guys like you over the coming years as I enjoy this vehicle.

An interesting story about SD acceleration, if you have the time. I'm a low-lander, from Houston, and some years ago I had an '81 SD which I drove on a tour of the high country.

Once underway, the car would run off from most on the road, but at altitude getting underway was an adventure-it probably needed some adjustment.

In Santa Fe at 5PM on Friday, just as everyone was getting off work and in a hurry to get home, I was caught first in line at a red light on an uphill grade. The light turned green and by the time it turned red I still had not made it across the intersection. Lots of horns.

Finally had to turn right onto level road to get underway. On that trip, through New Mexico and Colorado, stopping on an uphill grade became a no-no. A 90 degree turn across the highway would get it going-that's all it took-but better not stop unless the road was wide. Loved that car and drove it to 240,000 miles.

Ron Seals

Ha, ha! I'm laughing WITH you, not AT you! I haven't found it to be quite that bad. I drove it about forty miles today in mixed city/highway. MAN, I love that car - on the highway. And I'm getting use to it's quirks in the city. One thing I've really noticed is that it runs tremendously better once it warms up. And that includes acceleration off the line. T. G. Lambach said that it 'imperceptibly' drops into first gear when you take your foot off the brake at the stop light. Damned if I didn't notice it did exactly that most of the time. And I find that I don't have to floor it to make it go. I just have to finesse the go pedal to make it do what I want.

Thanks for the great story. I'll remember that if I'm in the mountains.

Rob (The continuing adventures of 300SD in Mesa, Arizona!)

I live in Vancouver BC, and as all geographically knowledgeable people know :-) BC is the ultimate mountain driving area in North America and my '85 300SD is a blast up any hill, including the Coquihalla as it's known here. The car is very fast, it will go around 120mph (not uphill), but I don't recommend something like that for an old car, it's a lot of fun driving this diesel, there must be something seriously wrong with yours, bring it to a competent mech.

cp

Nobody has yet said that once a diesel is warmed up, it will benefit from a heavier than normal foot, giving you closer to gas performance and not hurting anything. Do not be afraid to use the kick down, or to lift the foot slightly to force a change up when needed.

JJ

R_E_OD>

city/highway. MAN, I love that car - on the highway. And I'm getting use to it's quirks in the city. One thing I've really noticed is that it runs tremendously better once it warms up. And that includes acceleration off the line. T. G. Lambach said that it 'imperceptibly' drops into first gear when you take your foot off the brake at the stop light.

that I don't have to floor it to make it go. I just have to finesse the go pedal to make it do what I want.

You're absolutely right! When this girl is warmed up it's a whole slug easier to drive. It runs smoother at idle, accelerates better, and general performance is great. And I do use the pedal just the way you suggest.

One more thing I'd like to throw out to the group. Just above the mirror, there is the small visor flap and just above that is a tiny grill cover. Anyone know what is behind that cover? Is it possibly the climate control sensor? (I'm taking a stab in the dark on that one.)

Thanks!