kraut56

Yes, I use Autolite.

I keep hearing that boosted engines don't really like Platinum or Iridium.

Mine is NA

kraut56

You will get a misfire code if just one plug is at fault.
Reason: the engine controller "reads" the ionization post-firing in the combustion chamber using the two plugs.

Welwynnick

It does on the NA but not on the TT. The TT only uses the knock sensors for ignition control.

Does your NA give you DTC codes for each plug? On my TT, I have only ever seen codes for each cylinder.

BTW, the NA & TT spark plugs are different, whatever the manufacturer. Denso list different numbers and specs.

Denso VK20Y for the TT and S65, and SK20PR for the NA. The Amazon listing says SK20PR.

http://www.denso-am.co.uk/e-catalogue/

Nick

kraut56

No, it only gives a cylinder # misfire DTC code, but not which plug- which makes it a PIA to troubleshoot (back to the red inserts!).

BTW: I know an MB guy that converts engines to racing engines by adding turbos etc, and he too shies away from platinum/iridium plugs.

Turboaction

Since this car has so many damn spark plugs, I might try a couple different plug technologies and see if any give me more/less problems. Right now I have a mix of Denso and Autolite iridium/platinum plugs, but they are the same exact construction. If I can find standard plugs in the same heat range, I'll install them in the other bank and see what they look like at the following service interval.

I think my first upgrade on this car might be a limited slip differential. This poor car is going to be REALLY hard on tires now that it's making full boost with the intercooler circuit working. I may adjust the tune to 87 octane just to make the power more reasonable during the cold weather months.

kraut56

You don't need a limited slip diff on this car, because the electronic stability program does that for you.

I made the mistake of fully "punching " my S600 on a normal in town road at about 30 mph, the result was awesome as the electronics put brakes on the rear wheels and cut the engine somewhat. If not, for sure the rear end would have spun out the back of the car. I'll never do that again!

Turboaction

You have to pay attention if you use the throttle below about 50 mph! I agree the car does a good job with the brakes to handle the torque, but I feel the traction control wouldn't have to intervene as early with a limited slip differential.

Of course, I really should just understand this car isn't a race car and leave it alone. There really isn't anything wrong with it.

Today I got a nice flash of all of the ABC warning levels over the course of about 100 milliseconds. I was driving about 75 mph with a passenger over a big dip in the highway where the suspension nearly goes from full compression to full extension. The event happened so fast that I couldn't read a message, but I could just barely tell a red, white, and blue message was on the screen over the course of a small fraction of a second.

I don't think any of the accumulators are bad, as I just inspected both of them. I'm guessing I just pushed the system to the limit with the full suspension travel on all 4 wheels at "high" speed. At least now I know that once the ABC pressure drops, a diagnostic is displayed immediately. If I blow a hose, I'll have no excuses why I didn't pull over in time.

kraut56

Blowing hoses according to my friends at MB is not really an issue.
They rather leak and give you warning on these old cars.

I have punched mine above 50mph, and it goes like a "smooth" rocket, and again, you don't need a locking diff then.

Welwynnick

Those who have fitted an LSD say they're a big improvement on traction control.

I never thought ESP was very effective on my car - until it stopped working. I had a speed sensor wiring fault that took some time to troubleshoot, and in the meantime I carried on driving.

Only then did I realise how much work ESP did to keep me on the straight and narrow. It was really quite scary, and this was to someone who was used to driving powerful RWD cars without electronic nannies. In years gone by I would do opposite lock power slides at every opportunity, and became quite good at it (at low speeds at least).

The Mercedes was a real handful though, when you test the boundaries. Accelerate in a straight line, and when the rear broke loose, it would start to go sideways. No problem - off the throttle and correct the slide. But no, the wheels would keep spinning for a second, and nearly carried me off the road backwards. Similarly, I tried provoking a lock up in braking. Again, off the brakes, but it took a heart-stopping split second to release the wheel and straighten up.

The controls are slugged like they have a time delay to everything. Everything is designed around functioning electronic systems, and it really isn't meant to be driven by the seat of the pants. It just isn't that sort of car.

Nick

tusabes

The short warning burst is indeed a drop in pressure , most likely cause it's bad accumulator . It might have just been that one large bump that taxed the system but If you get these quick warnings more often over bumps, you'll have to replace them .

tusabes

My last hose leaked noticeably (drips on floor ) for about two weeks before it burst completely. If you're getting abc drips you can't ignore it , like you can often ignore small engine oil drips from leaky seals etc

kraut56

I agree, once they leak they will become a problem.

Weeps however I just monitor.

14 years is a long time for any high pressure hose.

tusabes

All w220 are now 10-16 years old . Most have some if not all of the original abc hoses so each one is just a matter of time till failure occurs

No one I know has ever replaced all (what is it , ten??) abc hoses . So virtually any used car with abc will have an abc hose failure

Welwynnick

I replaced ten hoses over the last three years, and haoz129 has probably done the same (though we're both probably a bit unusual).

Common wisdom in the hydraulics industry is that hoses have a limited shelf life, a limited operating life, and reduced life at high temperatures. There's no firm limit to operating life, but the best indicator I could find after a lot of research is 6 years.

Many people say don't wait for hoses to fail, like cam-belts; replace them pro-actively according to a preventative maintenance schedule, and certainly whenever they start to seep. 10 years is certainly long enough.

Nick

Turboaction

I'll certainly start replacing any of the hoses that are weeping or have visible heat damage. With that said, we have tractors that are over 30 years old with the original hydraulic hoses. It all depends on the environment they operate in.

Last night I had another fun experience with the ABC. I started up the car and was greeted with the red "ABC system failure, drive carefully" message. I stopped the engine, opened the hood, checked the level and everything looked fine. I re-started the engine and the diagnostic disappeared and the car drove perfectly.

I'm guessing the cold weather (8 degrees F) may have briefly stuck the pressure sensor. I've driven this car dozens of times since the repair in warmer weather and didn't have this issue.

Welwynnick

If it ain't broke.....

I still can't make up my mind whether I believe in that or not. Generally, I'd say don't go looking for things to fix, but we all know what happens if we don't change the oil regularly?

ABC hydraulics are a bit different to other systems, as it stores hydraulic energy in the accumulators. This means the supply system is always at full pressure when the engine is running. That means its a high duty cycle for the hoses.

In addition, the hoses in the lines to each strut can be considered to bear the weight of the car all the time, not just when the engine is running.

That, and the high temperature in the engine compartment mean the hoses have a hard time. I think ten years is when you can expect to have start replacing them. I just wish Mercedes had made better provision for this. ie: same flexible hose section at every location; easy access; removable connections; industry-standard terminations, etc.

Nick

Turboaction

I will definitely plan to change the rubber sections of several of the engine compartment ABC lines once the weather warms up (and when I'll be driving my summer car).

It really bothers me that I've had the ABC Drive Carefully light come on twice now shortly after starting the car, but if I shut the car off and re-start the engine the system works normally. I'll keep driving the car and see if this is just a cold weather phenomenon (it was -3 F last night).

Anyway, I appreciate all the feedback this community has provided. In exchange, I will continue to report my adventures (including solutions) with the ABC system.

Turboaction

So, I hooked up the diagnostics when the red ABC warning illuminated on the dash. I now have faults in the hydraulic circuit at all 4 suspension struts. The car performs the actuation tests ok, but I did notice the "raise the vehicle to the calibrated height" actuation doesn't work very well. There is usually at least 20 mm of error on at least one corner.

Let me know if you guys have any ideas. Since the actuations seem to work, I don't see how there is a physical fault in the system. I'm starting to think I should start sourcing a replacement ABC module. I imagine this won't be too impossible to find since so many people give up on the ABC system and remove it from their cars. I'm starting to question why I'm not doing that myself.

Also, my N70b1 in-car temperature sensor reads 0 C all the time. This is probably why my climate control doesn't work right.

Turboaction

Well, tonight I fixed my in-car temperature sensor. The thermistor had a broken wire, so I relocated the sensor to the outlet of the fan and secured the leads to the housing near the sensor with some hot glue. This will prevent the sensor from vibrating and fatiguing the sensor leads.

I still don't have a clue where to go with the ABC system. I ordered a spare controller for $60, as I'd like to rule this out before I start the long road of waiting for a strut code to show up (and not all 4 out of nowhere). I also have an engine oil leak from somewhere that is driving me crazy. I'm going to have to clean everything off and see if I can find the source. I'm guessing one of the oil cooler hoses or connections is leaking, because it's getting engine oil all over the ABC hoses in front of the engine.

wallyp

An old mechanic's trick for locating slow or hard-to-see leaks...

After cleaning the area, blow some cornstarch (available in your kitchen cabinets or any grocery market) over the area. It is a very fine white powder - hold some in your hand and blow by mouth. Don't worry - it is totally nontoxic, and easily removable. It will leave a barely visible white film over the area. Run the engine for a few moments, and the leak will often be clearly shown.

Turboaction

So.... the ABC hose that runs to the passenger front strut is weeping a tiny amount of oil, but the main culprit was that I apparently didn't get the lid on the ABC hydraulic tank correctly. I carefully re-installed the lid, cleaned everything off, and no more puddles. No more wonky ABC codes in the last few days of driving. Fingers crossed! I do now have a spare ABC controller. If I get more nonsense codes, I'll swap in the other module.

Turboaction

So, the car has been running/driving great lately, but I do occasionally get an "ABC visit workshop" code. The DAS shows a problem with pressure supply code, and when I run through the diagnostic tests, it says my rear valve block is malfunctioning (the front tests fine).

This may align with my random rear corner drops while I'm driving (only happened a few times). The car doesn't sag when parked, but I'm guessing one of the valves is sticking closed and not letting fluid in or out of the strut. What do you guys think? My plan is to order enough O-rings to rebuild both valve blocks and just clean and re-seal both of them.

_Ryan

I didn't read anything before this post, so apologies if it's been covered already...

There are four valves per block. Two control valves and two isolation valves, one per side.

The fact that your car does not drop when parked (the most common issue) indicates that your isolation valves are fine. These are the smaller of the valves in the block.

You could have a sticking control valve, usually caused by dirt or some debris in the system.

I would start by sucking out the reservoir and refilling with clean fluid. This should get you about 1.5 liters. Change the filter and run a quick rodeo to cycle the fluid through. Do this a couple of times and you will end up with a fair amount of fluid being pumped through and exchanged. After a couple days of driving, change the filter again and check the fluid condition. Once it's clean, see if you still have the issue. Sometimes this is enough to clear things up. If not, you will need to rebuild the valve block and having new, clean fluid won't hurt anything. Do not try and save some money by using cheap filters or not changing it. You need them to work. The new ones are 3 micron. This is pretty small and they get packed up easily when run with old fluid.

I would recommend against taking apart a valve block that is working fine. Don't touch them until you start to have issues. If you do remove the valve block make sure to support the wheels while you do it. If you take out the isolation valve while the wheel is free hanging it will pull the boot off of the strut and they don't like to go back together. You do not need to support the wheels if you only remove the control valves.

tusabes

Agreed do not touch the valve block if you don't have issues

Turboaction

Well, the car is parked again. I was driving the car and noticed a hammering sound that sounded like a rod knock. About the same time the sound started, the red "ABC Drive Carefully" message was displayed. The car no longer has ABC pressure. It looks like my replacement reman pump (for the original DOA reman pump) has failed.

And yes, the car had fresh Pentosin and a new 3 micron filter with a system flush using the "pitch" strut actuation.

If I can get a refund on the pump (still under warranty), I'm putting a conventional coil-over suspension on the car. If I can only get another replacement, I'll flush the system, replace the filter, and clean and re-ring the valve blocks. I think I had about 500 miles on this pump before it came apart.

I will mention, the morning before the pump destruction, I noticed a strange resonance sound right after startup. It went away after about a second, so I didn't think too much of it. I guess it was a warning sign that the pump was about to die.