Hi All,

I've just purchased a 2003 SL55 AMG in Obsidian Black, it's covered 67k miles and has a very comprehensive MB History and only 3 owners. It's had quite a bit of work done in the last 3 years, including a new roof pump and brakes. I've done nothing other than a set of new rear tyres.

I do have a couple of issues which i could do with advice on. I've read up on most of them and opinion seems to differ.

1) Slight cabin vibration in P and N - From what i've read this will most likely be an engine mount or transmission mount. Transmission Mount has been done in the last 3 years (20k miles). Watching the RPMs they fluctuate 50-100 rpm at idle but nothing massive and certainly no Hunting. The car drives fine with no other issues.

2) ABC Fluid - Suspension looks and works as it should (no noises or warnings). I've been through the history and i cannot find any history of fluid changes, pump replacements or struts. I've checked the fluid and it's light brown and doesnt spell burnt. I've read a lot of conflicting information about whether or not to change it, but would wonder what the general consensus is these days.

3) Occasionally Sticking in Park - Over the few days i've driven it, it does sometimes stick in park. I can see from the history that it has had a new selector module in the last 4 years. I'm hoping the issue is a brake light switch which i will get swapped. When the problem occurs it always seems to right itself after coming off and back on to the brake.

4) Slight Water Leak from under the car. After a drive yesterday, the car has been parked up. My O/H noticed a wet patch under the car this morning. Checking it, it's definitely water. It seems to be coming from the split in the front under tray (where the right hand side (as you look at it from the front) meets the right section). Looking from the top, it looks mainly like a/c pipes in that area. Coolant levels look fine and the drip doesn't get any worse if the engine is running. I've loosened the undertray and let more water out (it looks like it was collecting there), it's odd as we've not had any rain.

Any thoughts appreciated.

 

My 2003 SL55 has only 40,000 miles on it.
I replaced my ABC fluid a couple years ago.
Also did tranny fluid & filter and brake fluid.

Cheap maint. vs. expensive repairs.

 

1) you are right it is probably motor mounts. also check your front control arm bushings as these usually need replaced every 40k

2) change the fluid and get the new higher micron filter. the fluid is supposed to be green. when you change the fluid make sure to open the bleeder valve behind each wheel. This is the only way to get the fluid that is in the struts and between the struts and valve block replaced with new fluid. The fluid is much cheaper on amazon if you buy it in 1 or 5 gallon jugs. On an 03 your accumulators will likely also all need replaced. there are one on each valve block, a 2nd one on the rear for the return line, and one in the rear of the front drivers wheel well on the pulsation dampener. ALSO TAKE OFF YOUR ENGINE COVERS AND CHECK ALL ABC LINES. They will start to weep on the crimped ends before going and the 3 that are in the engine compartment are the 1st to go.

3) get this fixed immediately. the issue is common and it is a plastic selector part that breaks. to replace it you have to be able to get the shifter out of park, which if the part has fully broken is a huge issue. you can find on ebay where people have made this part as an upgraded metal unit to prevent this issue from arising again.

4) the water is condensation from the AC system dripping and collecting on the engine trays. nothing to be worried about.

5) other stuff that you will want to look at - 03 had issues with gas tank baffle weld breaking. when your tank is lower and you stop you can hear it clank around. the 2 flaps on the rear top cover go bad all the time as the plastic gets brittle on the hinged part and breaks. My car (also an 03) had them replaced at 40k and now at 89k needs them again. I plan on making my own hinge with black duct tape, which is what another member did. the front latch on the hydraulic top is the first to go, keep an eye on it as it will start leaking fluid onto the headliner. the soft close trunk goes bad due to a design flaw where they start leaking. the fix is easy and requires plugging some ports. cheapest place I've found to get mb parts is mbdirectparts.com (a dealer in Omaha, NE). Engine wise the idler pulleys are plastic and will break around your age and mileage. you can replace with oem or aftermarket metal. crank position sensors also go bad often.

 

I would definitely purge the ABC fluid. My car had 45K on it when I bought it 3 years ago, and I purged it over the first winter. I've also replaced the two accumulators and the two dampeners associated with the ABC system. I'll purge again with new Pentosin CHF 11S either this coming winter, or the following one. I've also installed a magnetic filter in the ABC line just ahead of the return reservoir, along with a new filter when I purged.

My fluid was still slightly green before purging. Since yours is brown, do it promptly.

Check out the idler pulleys and belt wraps from Eurocharged. These are improvements for the supercharger belt (also, since it is now 14 years old, might want to change that.

Gary

 

i too did the magnetic filter by just using one that was designed for tranny fluid. While it may help some with the valve blocks being made of aluminum i'm not sure how much it might actually trap with the magnet part. Of course its super cheap and should help filter out larger particles before the fluid hits the OEM higher micron filter, which is good.