Hi, Just got 87 300SDL 185K miles, love the car, some questions. During acceleration when turbo kiks in I see a lot of black smoke in the back , Is this normal? When turn ignition, aux fan kiks on, AC does not engage. Do you need to adjust timing? When cold you can realy feel the kik from the turbo, when the motor is warm it seems sluggish (what can it be?) And how do you conect the power antenna to aftermarket cd player? I have 2 extra wires and tried both of them and nothing happen, with original deck the amtena works. Please help. You guys are awsome! Thank you.

Congratulations on the SDL purchase, these are GREAT cars.
Some Black smoke under full throttle is normal and you can expect some grey smoke when first starting from cold at idle. Any excessive smoke at other times may indicate that oil is getting past rings, valve guides or turbo seals. Your Turbo is running all the time but really adds boost at 2000rpm+.

The Auxilliary cooling fan in front of the Rad. should only kick in if the temperature is getting to the 90deg+ range, it certainly shouldn't be on all the time. There is a sensor that switches it in at high temp. This may be faulty.

If the A/C Compressor is not engaging then first check Fuse #5. If this is blown there could be a couple of reasons. Shorted A/C Compressor clutch, or seized Auxilliary Water Pump. Unfortunately one can cause problems with the other (this happened on my SDL) as they are both on the same circuit along with the Automatic Climate Control (ACC). Check out both items in turn to see if one has a problem. The Aux Water Pump is a common problem and a pain to fix due to its cost and location buried between the two engine bulkheads. Disconnecting it is the best temporary fix.

If your performance is reduced when the car is warm, there could be many reasons but I doubt that the injection timing is out as this would affect the engine hot or cold. Undo the oil cap when the engine is running and up to temperature to see if there is any pressure. this would indicate "blow-by" due to worn rings or valves guides. Your car may just need an "Italian Tune-up" (do a search on this) if the car has been driven sedately and coked up the head. A compression test (hot) will also indicate any excessive ring or valve guide wear.

Can't help you with the antenna question, but these units are prone to failure so you may want to see if it works at all before you wire up your sound system to it.

Use the Search function here for further info and good luck with the car.

__________________
1991 M-B 560SEL Arctic White/Grey 99,000 Miles
1987 M-B 300SDL Ivory/Palomino 229,000 Miles (sold but never forgotten)
2006 Volvo XC70 Blue/Beige
1999 Porsche Boxster Arena Red/Savanna Beige
1986 Porsche 928S Goldweiss/Brown

Thank you for fast reply, what is the normal compression and how to test it. Also is ther easy way to replaced glow plugs on these engines or I have to take the intake manifold off?

Welcome to the world of the SDL!

1. Black smoke.
Black smoke is unburned fuel, ususally most noticed when engine is making more power. Some OM 603 smoke a lot, some not much. It can from late injection timing due to wear of the timing chain.

The previous owner may have adjusted the ALDA to raise the amount of fuel at a given pressure, which can add to the black smoke.

2. Aux fan.
Check temperature sensors. It should run with the A/C is on or when engine exceeds 105C. If it runs as you say, without starting the engine, suspect a switch or wiring fault or short. See Post #3 of this thread, and Search for others.
warm AC air/ aux fan on all the time @ normal temps?

3. Timing
Injection timing can be adjusted, as on all diesels. The OM 603 has two electronic methods, involving special tools with sensors that detect IP position. Dealer will have them, and some independent shops. They are a bit costly for the owner, several hundred dollars if I recall. See Post #8 of this thread.
Cam for vacuum pump destroyed

4. Radio and antenna
There are 4 plugs on the back of a Becker factory radio. Two are for speakers, one for power and one to activate the antenna. The radio switches 12VDC output to the antenna connector when the radio is switched ON. If I remember correctly, the antenna connector has a single blue wire.

The antenna motor has its own source of power. When the (blue?) wire is energized, the antenna either stays down, raises to part-height or full-height, depending on position of the Antenna switch on the dash.

You will have to get an adapter for your CD player, or if it does not have this function, connect the wire to a switched 12VDC source to raise the antenna when the car is switched on, and lower it when it is switched off.

Best Regards,
Jim

Start with the very simple stuff first, when was your air filter last changed?

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Thank you all for help. Fixed my antena(it was a blue wire), Found the problem with coolant temp. switch. A/C works now. Still have smoke, but working on Italian tuneup hahah

Great job!