1982 Mercedes Benz 380SL

[TAKerry]

Sounds like my ML320. Runs great, just like clockwork about 5 miles into the drive the electronics shut everything down. Let it sit and it would fire up and run fine. Not reliable enough to send my wife to work every day, been parked in my barn for 5 yrs now!

[Angelfish]

These kinds of problems are a pain.  I assume you've looked, but there are many discussions about ML320s doing what yours is doing.    Crank shaft sensor is commonly blamed.

 

And I found this, it would be easy to try:

 

I've taken the car key off the ring and I've turned my ignition key all the way on without cranking the car up for 60 seconds, waited 10 seconds and started it. I drove all day today and the car never cut off. I thank you guys from the bottom of my heart. I'm just curious though, was it the keys or the 60 second thing?

 

reply:

The truck lost throttle settings due to the battery disconnect. That '60 second' procedure resets the throttle settings.
 

 

 

16 hours ago, TAKerry said:

Sounds like my ML320. Runs great, just like clockwork about 5 miles into the drive the electronics shut everything down. Let it sit and it would fire up and run fine. Not reliable enough to send my wife to work every day, been parked in my barn for 5 yrs now!

 

[DrData]

Angelfish,

 

If you have not done s, I would suggest you test your coil. Your experience of driving about 15 - 20 minutes, waiting a while and the restarting sounds very much like the coil that failed on my old MG TD. It is a tricky issue…it seems like it should be a fuel delivery issue but it is not…failing coil gets very hot and simply quits. Sit by the side of the road for a bit and it cools down and becomes functional.

 

Great looking car…always liked them myself.

 

Cherrs!

[Angelfish]

2 hours ago, DrData said:

Angelfish,

 

If you have not done s, I would suggest you test your coil. Your experience of driving about 15 - 20 minutes, waiting a while and the restarting sounds very much like the coil that failed on my old MG TD. It is a tricky issue…it seems like it should be a fuel delivery issue but it is not…failing coil gets very hot and simply quits. Sit by the side of the road for a bit and it cools down and becomes functional.

 

Great looking car…always liked them myself.

 

Cherrs!

Well thus far the car is running well.  Can I accurately test the coil if it is not malfunctioning, or do I need to wait for the car to stall again?  The coil, along with the green ignition wire were next on the list, and I may just replace them for peace of mind (not to be confused with throwing parts at a problem, that's completely different).

 

What I did discover was the wire to the ignition module.  If I tapped on the plug to the ICM, the car would stumble or die.  I shimmed the plug with fine copper wire, one an each pin of the plug, and that problem went away.  I have only driven the car about 10 miles since so I'm not ready for a victory lap just yet.

 

And thank you, the more time I spend with it the more I like it.

[Angelfish]

On 5/25/2023 at 9:30 AM, Laughing Coyote said:

Post a picture of the harness and how it's plugged in to the sleeve please.

The plug on the left has been removed from the sleeve, right side is still in place.   The socket fits into the sleeve and then slides to the side to lock in place.

 

Edited May 29, 2023 by Angelfish (see edit history)

[Laughing Coyote]

Is there any manufacture stampings any where on the sleeve like a name? It looks like the wires were cut, soldered, and heat shrink. It may be the factory sleeve and connections, but the factory wouldn't cut them just a few inches away from the connectors and change wire colors. It looks like some of the black dash plastic was cut out some to fit it. If you have a test light you can test the wires. You can look up 12v test lights on line. Very useful for this type of stuff.

 

Yellow - constant 12v

Red - switched 12v (key on)

Blue/red - Could be illumination or 12V for power antenna

Brown - ground (usually on european cars)

 

The other wires on the other plug should be speaker wires.

[EmTee]

10 hours ago, Angelfish said:

If I tapped on the plug to the ICM, the car would stumble or die. 

That's a good find and hopefully was the root cause.  It wouldn't be surprising for the already loose connector to open up with increasing temperature and engine vibration...

[Angelfish]

15 hours ago, Laughing Coyote said:

Is there any manufacture stampings any where on the sleeve like a name? It looks like the wires were cut, soldered, and heat shrink. It may be the factory sleeve and connections, but the factory wouldn't cut them just a few inches away from the connectors and change wire colors. It looks like some of the black dash plastic was cut out some to fit it. If you have a test light you can test the wires. You can look up 12v test lights on line. Very useful for this type of stuff.

 

Yellow - constant 12v

Red - switched 12v (key on)

Blue/red - Could be illumination or 12V for power antenna

Brown - ground (usually on european cars)

 

The other wires on the other plug should be speaker wires.

No markings on the sleeve.  Would I expect to reuse it with a new DIN radio?  I'll be looking at the 'retro' style that would have the correct appearance for the car. 

 

The car is supplied with a power antenna.   With the color code you provided I could easily build a harness into the radio.   Are the molex type connectors reliable for this sort of thing?  That would save fumbling around in there with spade connectors.   I would use a molex between the factory wires and the supplied radio harness. 

 

Thank you for your help

Edited May 29, 2023 by Angelfish (see edit history)

[Laughing Coyote]

You won't be able to reuse the sleeve with a new stereo. You will have to purchase a new stereo that is a DIN mount, which most of them are and re wire it to the factory harness. You can buy a harness kit so you retain the factory connectors you just have to search for your car. It's hard to say what was in there if there was no markings on the sleeve. You can purchase older Blaupunkt stereos on Ebay that would look fitting for the car since it's a German brand stereo or newer ones from any large retailer. You can test speaker location by using a 9v battery (the little square ones). You put the negative wire of the speaker on the negative tab of the battery. Then use the other wire and just tap it to the positive side of the battery and you should hear the speaker make a popping noise. Then you know where they are located.

[Angelfish]

Did some testing.

Yellow (gray from the factory) Ground

Red: Constant 12v

    these wires go to their own two conductor plug behind the radio

 

Brown (looks orange in the picture): Ground

Red / Green: Switched 12v

Blue / Red: Power Antenna (because it works!)

 

Does it make sense to have two grounds or do I need to examine this more closely?

[Laughing Coyote]

I would check the Yellow (grey) one when you turn on the parking lights. It could be a illumination lead. Brown on European cars is usually the ground.

[Angelfish]

Gray wire, spliced to yellow, is indeed switched with the parking lights.  

[radiofixer]

Your original radio can have new electronics installed so the look and fit does not change. In addition if interested in the modern features such as Bluetooth and USB the can be installed along with the main board. They have been done to many Blaupunkts of that time frame.

For more information you can send a private message or call text @ 253 576 4076.

 

Bill

[Angelfish]

On 5/30/2023 at 1:17 AM, radiofixer said:

Your original radio can have new electronics installed so the look and fit does not change. In addition if interested in the modern features such as Bluetooth and USB the can be installed along with the main board. They have been done to many Blaupunkts of that time frame.

For more information you can send a private message or call text @ 253 576 4076.

 

Bill

The radio was missing altogether so I'm looking at options.   I would like to have one that looks correct with the car, either new or reconditioned.  It was supplied with a Becker but those are pricey. 

[radiofixer]

I have one that's a non working one for a filler. It's actually made by Alpine for Mercedes which it says Mercerdes on the radfio.

Here's a picture of correct radio.

[radiofixer]

Unfortunatel it was realized that that this one cannot have newe electronics installed. Saw the wrong radio intially.

 

[Angelfish]

I put 175 trouble free miles on the 380SL today. I wouldn't consider that much of an achievement except that this car had sat for at least 10 years and was only brought back to life in the last few months.

The stalling in traffic turned out to be a loose connection to the ignition module that I fixed by placing a single strand of copper wire in each of the 4 prongs in the socket, this shimmed to create a more reliable contact.  Prior to this I was unable to drive the car more than 15 miles without stalling.
 

The faster its going the happier it is, Montana's generous speed limits were easily exceeded. There's some vibration in the 65-75 mph range, and little bit of howl under load at the same speed that I'm blaming on the rear end. Over 75 it just flies.  The odometer seems to read about 1% high.

Handling was a little bit squirrely, not a lot, and I'll blame that on every single piece of suspension rubber being 40 years old.

Made it back before the rain and didn't even have to call a guy with a truck and tow rope.

[Laughing Coyote]

Not sure if that car has a flex coupling like the BMW on the driveline, if so I would change it out. 

[Angelfish]

12 minutes ago, Laughing Coyote said:

Not sure if that car has a flex coupling like the BMW on the driveline, if so I would change it out. 

It has two rubber flex discs, they appear to be in good condition but should probably be changed just due to age.  Not too hard of a job from all accounts.

 

Meanwhile, I discovered that the rear end howl is a Mercedes thing and can sometimes be cured by using moly gear oil.

[EmTee]

20 hours ago, Angelfish said:

There's some vibration in the 65-75 mph range

Check tire run-out and balance.  Do you feel it in the steering wheel (front) or seat of the pants (rear)?

[Angelfish]

3 hours ago, EmTee said:

Check tire run-out and balance.  Do you feel it in the steering wheel (front) or seat of the pants (rear)?

I'd have to say in the seat.  The tires are new but that doesn't always mean they are balanced correctly.  It's a simple thing to check.  This kind of vibration is commonly attributed to driveshaft flex discs and/or carrier bearing.  But I remember when I first drove it before I bought it thinking that it had a tire out of balance.  

[EmTee]

If it comes and goes I'd suspect a tire.  I have a similar issue on the Allante'.  There's a 'bump' I feel in the seat that seems to come and go.  I'm suspecting a rear tire imbalance.  I also need to check...

[Angelfish]

No longer missing a front tooth, although the new one is a little crooked so I'll have to take a look at the mount.

[EmTee]

Look'n good!

 

[Steve_Mack_CT]

Things to look at re eradicating squirrels.  Steering box, it's adjustable but we went with a rebuilt unit.  Steering shaft link, these are a known wear point on these cars and of course front end rubber, tire pressure last.  What a difference the new steering box and rubber components made on ours.  Steady, confident left lane long range hi speed vs. oh my, we are just over over 60 mph and she changes lanes all by herself... 😉😁👍

[Steve_Mack_CT]

Of course the much more moderately priced MG went to rack and pinion decades earlier... 😁😁

[Angelfish]

Since last post I have put over 2000 miles on the Mercedes, including a 1200 mile round trip to Denver to do a Colorado School of Mines campus tour.   My son drove it a bit, I'd doze off and wake up irritated that he was driving 55 mph across Wyoming.  Then I'd look over and see that he was going closer to 85.  On the way back we did 540 miles in 7 1/4 hours start to finish.  I like this car more every time I drive it.   We had the hard top on for the Denver run and it will likely remain in place till next spring. 

 

It was good to have an upcoming road trip as it motivated me to get a lot of little things done.   I tore the dash apart (again) and fixed the defrost diverter, repaired the climate control board, balanced the wheels, ran a USB power socket off the battery, added and replaced some sound insulation below the parcel shelf, replaced the wiper blade inserts, repaired the broken battery hold down strap - known issue with theses cars,  and probably a few other things I don't remember now. 

 

Now it's on to bigger things: smoke test revealed a vacuum leak around the throttle rod, which might explain the 15 mpg.  (*edit, 16.4 mpg)   Do you know anyone who'd be interested in rebuilding the throttle body?  And I have to pull the perfectly good, non leaking radiator to replace the AC compressor.

 

 

 

Had to cut a little hole in the defroster duct and do the work with needle nose pliers.

 

 

Used a strap hinge to repair the battery strap, I consider it better than new as it now if folds out of the way to remove the battery.

 

 

Memory card didn't like this one, but I've gotten proficient at pulling apart the inside.

 

Edited November 16, 2023 by Angelfish (see edit history)

[Laughing Coyote]

What did you ever do about the stereo?

[Angelfish]

14 hours ago, Laughing Coyote said:

What did you ever do about the stereo?

Thank you for the follow up.  I pulled the cassette deck out of the boat (in dry dock with a split outdrive seal), a Sony XR-2300 from the early 90s.  It had the correct orange LCD display and it was free.  It fit cleanly in the DIN sleeve that came with the car.  The install was non-invasive, and everything works including the power antenna hooked to the amplifier remote.

 

I replaced the dash speakers with 3 1/2" Pioneer 3 ways.  They do almost nothing but I refuse to cut up the car to put in larger speakers. 

 

I ran a rear channel and hooked up my mismatched 6x9s in the cheap pre-made boxes.  They sound terrible and look just as bad.  I thought they were out of phase so I switched one of them, it may sound marginally better but still pretty bad.  I will look for a set of good free standing car speakers that I can set on the parcel shelf.  

 

But this buys me some time to look around for something better that will match the look of the car.  Maybe an original Becker will drop into my lap.

 

 

Edited November 2, 2023 by Angelfish (see edit history)

[Steve_Mack_CT]

22 hours ago, Angelfish said:

Since last post I have put over 2000 miles on the Mercedes, including a 1200 mile round trip to Denver to do a Colorado School of Mines campus tour.   My son drove it a bit, I'd doze off and wake up irritated that he was driving 55 mph across Wyoming.  Then I'd look over and see that he was going closer to 85.  On the way back we did 540 miles in 7 1/4 hours start to finish.  I like this car more every time I drive it.   We had the hard top on for the Denver run and it will likely remain in place till next spring. 

 

It was good to have an upcoming road trip as it motivated me to get a lot of little things done.   I tore the dash apart (again) and fixed the defrost diverter, repaired the climate control board, balanced the wheels, ran a USB power socket off the battery, added and replaced some sound insulation below the parcel shelf, replaced the wiper blade inserts, repaired the broken battery hold down strap - known issue with theses cars,  and probably a few other things I don't remember now. 

 

Now it's on to bigger things: smoke test revealed a vacuum leak around the throttle rod, which might explain the 15 mpg.    Do you know anyone who'd be interested in rebuilding the throttle body?  And I have to pull the perfectly good, non leaking radiator to replace the AC compressor.

 

 

Had to cut a little hole in the defroster duct and do the work with needle nose pliers.

 

 

Used a strap hinge to repair the battery strap, I consider it better than new as it now if folds out of the way to remove the battery.

 

Love the battery strap idea.  I remove the nuts rather than continue to bend mine.  I think I have at least one busted one I held for some reason and one that was crudely welded.

 

But the statement that describes my feeling to a T is I like this car more every time I drive it.  👍😊😎

[Angelfish]

That was the other thing, valve cover seals. 

 

Used OEM seals and new copper crush washers.  I had to order a tiny little 1/4" torque wrench so I could get the correct 3 newton meters.  Hasn't leaked a drop in over 1200 miles.  

 

Edited November 2, 2023 by Angelfish (see edit history)

[Angelfish]

15 minutes ago, Steve_Mack_CT said:

Love the battery strap idea.  I remove the nuts rather than continue to bend mine.  I think I have at least one busted one I held for some reason and one that was crudely welded.

 

But the statement that describes my feeling to a T is I like this car more every time I drive it.  👍😊😎

Thank you, the strap did work out better than I expected, folds politely out of the way to pull the battery. 

 

I think I said it earlier, but I told my wife that I didn't know till I had one, but it's the car I always wanted.  

 

The other idea was to tape off the end of the chrome at the bottom of the hard top, it does seem to help with the wind noise. 

 

 

[Steve_Mack_CT]

Nuther option might be to stick some foam like one uses for window AC units in there, we just get a little noise...  😉😊

 

We, I should say me kicked around a 55 57 Tbird as an alternative to the SL but everyone else here likes the SL better.  As values of those have flattened, declined a bit and good SLs appreciated a bit it would be a nearly even swap but honestly these are fantastic long range cruisers so it would be a tough call..

Edited November 2, 2023 by Steve_Mack_CT (see edit history)

[Angelfish]

On 11/2/2023 at 9:28 AM, Steve_Mack_CT said:

 

 

We, I should say me kicked around a 55 57 Tbird as an alternative to the SL...

How do they compare?  On paper they are very similar.   My only complaint with the SL is when passing another car, it's not snappy in the 60-80 range.  My wife drives a twin turbo Ford Edge Sport and that thing is a rocket, accelerates like a motorcycle.    But the SL is a wonderful traveling car combined with nimble handling in town, the perfect combination.  

[Steve_Mack_CT]

Been a long time since I have evrn sat in an early bird but side by side it's a bigger car, not ridicolously bigger but noticeable.  More creature comforts and safety features in the SL and while it feels dated in comparison to today's cars  it is way ahead of thr esrlier Ford.

 

[Angelfish]

Another 1000 miles.  Visited Mom and Dad for a few days.  Came closer to hitting a deer than I have in the last 25 years.   Wet road, indecisive deer, but it stops straight and quickly.  Back end thought about breaking loose but didn't.   

 

This was the first run with working cruise control.  I found an excellent writeup on diagnosing the CC and was able to pinpoint the module, although it's the problem 90% of the time.

 

https://www.benzworld.org/threads/guide-to-cruise-control-testing-and-repair.3127196/

 

19.4 mpg this run.

 

Anyone ever try to fix the rear window defroster?  I might let that one go.

 

And I've got the occasional high idle, very common Mercedes problem.   The idle air valve appears to be working as does the cold start valve, so once again that leaves the control module.  

 

AND, the rear end howl is back, in force.  The moly gear oil had it pretty much eliminated it for a long time so I'm not sure what's happening there.  Don't think it's the carrier bearing, it's directly related to torque on the drive line (accelerating) but not speed.  Let off the gas at whatever speed and it subsides.  

 

And another thing.  A dinner guest while I was there explained the indecisive deer.  Deer are, of course, prey animals.  The wolves and other predator animals are smart enough to learn the behavior patterns of their prospective dinners, so the dinners have to be completely unpredictable in their evasion tactics.   This works if you're trying to eat them, but is a hinderance if you're trying to avoid them.  Hm, maybe that means that instead of trying to avoid the deer, you should actually aim for it.  Anyone have an opinion on deer whistles?

 

 

 

 

 

Edited November 16, 2023 by Angelfish (see edit history)

[Angelfish]

With any luck it will be back on the road soon, new AC compressor, driveshaft rebuild and throttle body rebuild.   Smoke test found a leak around the butterfly shaft and the U joint was notchy.   New pinion seal, carrier bearing, flex discs and transmission mount.  Since I was under there already.

 

 

 

Edited April 19 by Angelfish (see edit history)

[Steve_Mack_CT]

How was flex disc job Fish?  I should do mine.  Inspection shows no cracks but ya know 35 years old now... 

[Rivguy]

The idea of aiming for the deer is actually a good idea, while braking of course. At least you know where the deer is at that point, and it's unlikely to just stand there as you get closer. It will move somewhere else and hopefully you can avoid it. That same advice was given to me by a CHP officer about how to avoid a car that spins out across the highway ahead of you. Aim for where it is and hopefully it won't be there when you get there! 

I always thought that those SLs would be embraced by fans of the early T Bird, though the Benz is more complicated and harder to fix. My Father in Law had an early 450 SEL and it was a pretty Impressive car.

[prewarnut]

On 11/2/2023 at 12:05 AM, Angelfish said:

Thank you for the follow up.  I pulled the cassette deck out of the boat (in dry dock with a split outdrive seal), a Sony XR-2300 from the early 90s.  It had the correct orange LCD display and it was free.  It fit cleanly in the DIN sleeve that came with the car.  The install was non-invasive, and everything works including the power antenna hooked to the amplifier remote.

 

I replaced the dash speakers with 3 1/2" Pioneer 3 ways.  They do almost nothing but I refuse to cut up the car to put in larger speakers. 

 

I ran a rear channel and hooked up my mismatched 6x9s in the cheap pre-made boxes.  They sound terrible and look just as bad.  I thought they were out of phase so I switched one of them, it may sound marginally better but still pretty bad.  I will look for a set of good free standing car speakers that I can set on the parcel shelf.  

 

But this buys me some time to look around for something better that will match the look of the car.  Maybe an original Becker will drop into my lap.

 

 

For you guys with MBs, Porsche makes a classic-styled radio with two knobs and 3.5 inch touch screen for clients with older 911s. It has nav, bluetooth, Sirius radio, and Apple Carplay compatibility in a single DIN package. Too bad MB doesn't offer this (from what I think I know). Porsche wants $1100 so not cheap but it wouldn't be hard to wipe off the small Porsche text at the top of the unit.....I don't have a pic but just search for Porsche classic radio. It's at least German high quality plastic....