LOUDERplease

New to group. Contemplating buying a 2008 SL550 w/80k miles

I’d appreciate any advice on what issues to look out for during pre-purchase inspection.

For instance:

? Intake manifold throttle flap (broken plastic) leads to low torque at low rpm?

? Balance shaft issue? (manufacturing defect solved prior to 2008?… but might still be an issue given the age?)

? Timing belt stretched?

? Convertible top wiring harness?

Any advice would be much appreciated. Thanks.

cdk4219

Only one of those concerns pertain to the sl550, as it has a timing chain, the roof problems are almost always hydraulic flap or cylinder failure, and the v8 has no balance shaft.

However certain year m273 engines have chain sprocket failure, but I believe the 08 is out of that issue.

The car will have issues with hydraulic suspension, convertible top problems, battery control module issues( with no parts available to fix) shifter issues and vacuum pump trunk latch issues, among other normal items like motor mounts transmission mount, and at 80,000 miles probably quite a few front suspension components. Hydraulic problems are around that mileage as well.
If you cannot do repairs yourself, these cars aren’t any bargains, lots of specific expensive parts and expensive to maintain.

TripleDown

Find one with less miles...so many of these were third or fourth cars in a household and there are many out there with under 50k. Properly maintained these can be very reliable, even with the complex mechanical systems involved.

slkfla

I agree the R230 can be expensive to maintain but I feel it is worth it enjoy the benefits of a beautiful retractable hardtop GT. Not really a sports car but sporty just the same. 2008 would be a great choice with the benefits of the 550 engine and ABC 2. In my opinion it kind of got hit with an ugly stick the next year.

JettaRed

iTrader: (1)

Exactly! And if you are a DIYer, be prepared to spend a little money on specific tools and maybe a garage lift, such as a MaxJax or similar lift. These are amazing cars, but they ain't your Honda Civic or Toyota Corolla.

tonylinc

80K is hardly any miles for a Mercedes, Drive the car, go fast go slow go all around, if you like it... buy it. They are FANTASTIC cars.

MBNUT1

Did they revise the ABC in 2008? What changes were made in 2009 besides the cosmetic ones, air-scarf and the infotainment? Did they drop the SBC braking then?

cdk4219

From the R230 guru himself. SBC brakes remain, realistically the engine was the biggest change, and the first years of this engine weren’t particularly better than the m113 it replaced. It’s just slightly newer and maybe slightly better. The R231 cars seem to not have the issues the 230 cars had early on, but again they are much newer.

MBNUT1

Thanks for the reply. So ABC2 occurred for what model year? 2007 (US) was the first refresh (mainly engine as far as I could tell) and 2009 was a true facelift. Have the ABC2 cars demonstrated greater reliability of the ABC system? So all R230's have the SBC brakes?

cdk4219

I believe 2007, and they aren’t better, again just newer.

Tom Manning

There are two height sensors on the struts in ABC1 - one of them was dropped for ABC2. The pulsation dampener was moved from the wheel well to the pump, probably to smooth out pulses at the source.

There do seem to be fewer issues reported with ABC2, but as mentioned that could be because it's newer. Hoses and valve blocks will surely be needing attention by now too.

TripleDown

Let's not forget the biggest (although seemingly small) benefit of ABC2 - the inline filter.

And although I get that the M113 has its fans (great torque and reported reliability), let's not fool ourselves into thinking the M273 is only "slightly" better. It's a HUGE leap in power and makes even more power than the NA AMG M113 used in the SLK/CLK. Driven back to back, I cannot imagine anyone saying that an SL550 is "slightly" faster than and SL500 in an R230. While it's no SL55, the M273 equipped SL550 was enough to make me realize that maybe I didn't need an SL55 for 99% of my needs.

Another reason to consider the 2009 and later is the much improved Harman Kardon audio system. Adding a bluetooth dongle is simple and cheap so you can get your phone music into the system. That's not trivial in the earlier Bose setup.

MBNUT1

Ok focusing on the M273 for a second. There was the issue of timing chain sprocket wear which I believe is confined to the early ones correct? Secondly there was a bore scoring issue. Was that confined to a batch of M273's that started in 2010?

TripleDown

Idler sprocket was fixed early on and bore scoring is an M157/M278 issue, not M273.

MBNUT1

There was a run in 2010 of M273's and M272's that had cylinder scoring. See attached.

I know one guy with a 2010/1? E550 which has this issue.

Not sure I trust the early date as I think mine has it and it was an early production E350.

Tom Manning

Let's not forget the biggest (although seemingly small) benefit of ABC2 - the inline filter.

Same filter in the top of the tank in both systems, right?

MikeJ65

The 2008 is my favorite year. Still the classic style, but the best suspension and the best base powertrain. I do believe that the ABC2 valve blocks are much improved even though they are not rebuildable.

Tom Manning

Odd no-one has posted a way to rebuild them yet, as they had to assemble them somehow from new.