Marco03s55

Hello everyone, let me start off by saying I am new here. I have just purchased a 2003 Mercedes S55 AMG with 147,000 miles from a private seller. The car is in great condition and has nothing done to it but a resonator delete. I know of the insanely expensive repair costs, but I found one for a great deal and I could not pass up! How should I go about basic maintenance on this beast? Also, I would love to upgrade the ECU, tune the car, upgrade the pulleys, but would this compromise the cars “reliability”? If so, what problems could I expect to run into. Thanks in advance!

Agent-A01

Won't hurt reliability as long as good parts are used.

If you go for power mods you'll want to at minimum replace the IC pump with the latest bosch 010 version.

M113 are very stout engines. Just make sure your fluids are all good.

PillDrive

I had an 03 S55 for 7 Years and most of my money went into the ABC system. (3 pumps and one hose after another which also made 2 of the 3 pumps fail)
I would rip out every rubber high pressure hose in the system and replace them and all accumulators. While in there i would rebuild the valve blocks and then flush the whole system. After that you wont have to worry about that system for awhile BUT i would flush it every 2 years.
Other then that i did not have to many things go wrong. And i ran it for 170K for a total of 250K when i sold it. As far as i know it is still on the road. No major engine or tranny work other then fluids. I flushed my tranny every 35-40k.

Good luck with it.

GrepAwk

All fluids and filters: engine oil/filter. Tranny oil/filter. Engine air. Cabin air. Fuel. You are fortunate ‘03 has a transmission dipstick tube and oil dipstick tube. (You need to buy your own tranny dip stick)

The electrical connector ($12) that goes into the tranny sometimes leaks. Replace it when you drop the pan for the tranny fluid/filter change.

ABC including flushing out old while pouring in new Pentosin CHF 11S until nice clear green comes out the reservoir return pipe. Bleed at each wheel arch. Also doesn’t hurt to replace all the ABC accumulators (I think there are 3 or 4). Replace ABC hoses that are leaking. Remove ABC Valve bodies (1 in front of left front wheel well + 1 above/behind left rear wheel well) and check the 4 solenoids in each for worn o-rings that could cause leaks. Most people dump these cars when ABC breaks.

Antifreeze for engine and supercharger intercooler.

Change supercharger oil (Mobil Jet Oil 2).

Change front pulleys. Plastic OE ones wear out and bearings get squeaky before they blow.

Next common issue is leaky vacuum lines that control the soft-close door lock and trunk lock mechanisms. Trace leaks and jbweld them,or replace components. Pump is in trunk on left side behind carpet wall.

Rear diff gear oil replace.

Brake fluid flush out old stuff at each wheel every 2 years.

Usual things like trunk lid struts, wipers, battery (in trunk).

Replace the alarm horn behind left front wheel well liner, if you find the beep is not working. It has a small battery inside that also dies after too many depletion cycles in storage. When it dies, it sets alarm system failures.

dwillia3476

Reading this make me wanna sell mine before all of this start to happening.

maw1124

Post #4 is very comprehensive and by my estimate less than $5k worth of work. Maybe closer to $3500 if you have a good indy who knows these cars, which by now everyone should. R&R the ABC Valve Blocks is probably overkill if you do the rest. If you can't afford $5k on these cars, yes sell it and RUN (don't walk) away. That's not a lot of money for what you're getting. That's a once every 100k mile list, except for the fluids -- oil every 5K; ABC & Brake every 30k, transmission fluid and plugs every 50k. The maintenance on these is the same as everything else in the fleet, except for the ABC fluid every 30k. You'll change the accumulators once in your ownership only, unless you keep it forever, in which case you won't mind doing it again.

maw

wfooshee

I would suggest that post #3's issue with ABC hoses was actually an issue with failed accumulators. Had he started with accumulators as soon as a hose blew, he'd never have seen another blown hose. The accumulators are there to absorb pressure spikes and release pressure into the system, and when they have no capacity to take in the spikes, the hoses have to do it. They can't.

Don't discount the importance of a valve block rebuild. Those seals decay, and fill the fluid with black gunk. But the first thing to do in the ABC system is replace the accumulators.

maw1124

I agree. I've replaced one block. In retrospect I think that may have been a bit hasty, especially since the other one is still going strong. But oh well. I'm left to conclude that if the fluid never becomes black gunk, the block will be fine too. But who knows. I would think though that by now (like since the original 6.3) MB would have their seals down to a science with hydraulic fluid but maybe not. From experience, are people here convinced that a rebuild as opposed to a replacement of the block is as good as factory?

maw

wfooshee

Personally, I'm thinking the valves don't break, the seals decay. I see no reason a rebuild isn't as good as new, and it's certainly cheaper!!!

When I bought it last year, my own car sagged at the rear after driving about 15 minutes, but that stopped with new accumulators. It was slightly low on fluid, but hasn't lost any since topping up with less than a quart. The ABC doesn't work, though, as the button on the dash had no effect on the ride height. If the car sits and sags, or is parked on a twisted site (one wheel sitting up higher in the car,) it resumes a good level when started, but it never seems to change after that. I'm looking to do a valve body rebuild soon, and investigating a strut rebuild as well. I can rebuild the valve bodies, the struts will have to be sent of, along with a bunch of $$$$.

Even after doing that, I won't have spent all of the insurance money I got for my previous car...

dwillia3476

I'm leaving my 03 bone stock, want the tune and all but don't want to modify the electrical system, so just torn between getting the best sound out the pipes, noting to nauseous, but rumbles!!

maw1124

The tune is just software, will advance timing a bit, shouldn’t hurt the car much, but it’s only 5% more power, I think so I don’t know if it’s worth it. The car is jumpy enough as it is. An XPipe instead of the center resonator will get you more grumble, after that is resonator delete. But neither qualify as “bone stock”. Unless you foresee a time where bone stock we’ll cared for examples will command huge premiums, I say do what you want with the car. You’ve already paid your money, the next buyer may or may not. We all tend to think cars will be more valuable in the future, until we realize they’re just cars and that’s just a way to justify our purchase.

Cheers,

maw