M.Benz Quality Question - chukter
My son is seriously considering purchasing an M.B. SL 280/320 of circa 1997 vintage.

Can someone please advise when the build quality on these superb vehicles was affected by the severe cost cutting measures introduced by their accountants which had such a detrimental impact on quality, as I believe the model he is interested in, was made up until 2000/2001 ???

Any advice would be much appreciated esp from Aprilla & Roger Jones.
M.Benz Quality Question - zm
He need'nt worry. The R129SL series was one of the last of the 'old school' mercs, dating from 1989, prior to the over use of electronics and rust does not seem to be too much of an issue either. The same with W140 S-Class models of this era as well. Have a look on Google for more info.
M.Benz Quality Question - Roger Jones
I agree. The R129 is one of the old school, although like all others it has water-based paintwork from August 1995 onwards. If two-seaters did anything for me, I'd be seriously interested in one, but the one I'd seek out would have a panoramic roof (an expensive option originally), which to my eye looks much better than the standard stubby hard top.

I'd have no qualms about the 320 straight-six engine, which I have in my W124 Coupé and is excellent -- very smooth and plenty of torque lower down than its predecessors -- and ultimately cheaper to maintain than the V8s, although it probably doesn't yield more than a couple of extra MPG (it's the very last of the very long line of MB straight sixes).

The R129 is surprisingly heavy: 1820kg to 2020kg, depending on the engine.

0-100 kph times:
300 straight 6 M103 engine -- 9.5 sec.
300-24 straight 6 24-valve first M104 -- 8.4 sec.
320 straight 6 matured M104 -- 7.9 sec. (figure not available, so that's for my car)
500 V8 -- 6.2 sec.
600 V12 6.1 -- sec.

There's a pile of info and advice out there, and it is worth joining the MB Club (I'm merely a member, not a promoting officer):


Other sources:







The data are from my official MB handbook, Technical data passenger cars. Shout if you want more.
M.Benz Quality Question - ForumNeedsModerating
My son is seriously considering purchasing an M.B. SL 280/320 of circa 1997 vintage.

Worth maybe considering also that 1998 (MY?) the SL's had a minor facelift - nicer cabin & fascia - and probably
a host of mechanical refinements & improvements too

M.Benz Quality Question - Roger Jones
Here are some more useful links:



Plus, I referred to the 320 straight-six M104 engine. The 320 will be a V6 in the later years (post 1996, I guess).
M.Benz Quality Question - chukter
Roger - Thank you for some excellent links, which I am still reading through. From my reading so far, it seems that the 320 straight six engine was used up until 1997 and then superceded by the V6.

Would I be correct in thinking that the straight six was the superior (less complicated) engine of the two and possibly the one to go for.???

Once again thank you for your help & advice.
M.Benz Quality Question - Aprilia
IIRC the V6 engines (M112) were introduced in '98 to coincide with the mini-facelift - prior to that it was the M104 (I6).

These are nice cars, but not really 'sports cars' - they are built for cruising and the handling is not very agile.

The suspension and powertrain are likely to be sound - but they can suffer from rust, so check like any other Merc from this era.

I think the biggest issue will be finding a good one that isn't overpriced. These cars can attract 'dodgy' owners, so you see a fair number that have not been looked after, been crashed, abused etc.
M.Benz Quality Question - chukter

>>>>>but they can suffer from rust, so check like any other Merc from this era>>>>

Aprilla - This is one of my main concerns, so are you implying that their build quality problems had already set in by 1997 - If so what year would you recommend going back to before the tin worm gremlins set in.????
M.Benz Quality Question - Aprilia
The rust problems on MB cars are not traditional tin worm (i.e. perforation from within) they are due to poor adhesion of the primer coating under the paint. I think the move to water-based primer coatings was around 1995.

MB used to use an epoxy-based weldable primer coating (Bonazinc) which is supposed to have a 30 year life. The snag with Bonazinc is that it has a relatively high resistance and so welder tip erosion is high. Also it needs a high curing temperature. They moved to a water-based primer to get around these problems - but unfortunately the results have turned out to be a bit 'unpredicatable'. This was coupled with a move to water-based top coats and they put them on very thin (100um, as opposed to a more typical 250um). So you have a less stable primer coating and a thinner and harder top coat which made chipping more likely.

I think when the corrosion problems came to light initially, MB were fairly generous and would replace panels without argument. As more problems came out of the woodwork they have toughened up and now a lot of cars seem to get a flatting down and a blast with the spraygun - just delays things. Note that the MB warranty (as I understand it) covers perforation and not corrosion due to chipping etc.
M.Benz Quality Question - Armitage Shanks {p}
Once the rust and quality options are resolved and build year decided I can advise against the 280 - very underpowered for the weight of the car .
M.Benz Quality Question - Roger Jones
I'm sure Aprilia is right to raise a corrosion flag, but I've seen very few reports on the MB bulletin boards. Perhaps they took more care over one of their flagship models, which will have been built in Sindelfingen (perhaps Bremerhaven, but I don't think so).

I've also seen few if any reports of problems with the V6 320.

If it were me, I would go for the M104 320, partly because I'm very happy with it in my Coupé, and I would be inclined to look for a pre-8/95 one for better paintwork. My first Coupé had pre-water paint, and its finish was perceptibly better than that on my present one (delivered Feb 96), although at the time I put it down to the former having been maintained better than the latter and I didn't know about the manufacturing change. I think the paint was actually thicker, but it was still not as thick as on the Audi 100 that it replaced (a truly great paint finish).

My angle on the engine is that I like something that's the last of the line, with the stability implicit in that. However, both the M104 and M103 are prone to head-gasket failure from, say, 70k onwards. A problem, yes, but a manageable problem when you know about it and budget the £500+ to get it fixed (knock it off the purchase price if it hasn't already been done). Many owners carry on regardless of minor leaks (oblivious or in denial), but I've bitten the bullet on my M103s in the interests of long-term use (no problem yet on the M104). You're almost certain to find things that need doing in a ten-year-old car; owners become very slow to fix things when a sale is in mind.

All in all, V8s aside, I'd take my time to seek out a 1994 or early 1995 320 with a ton of evidence of having been looked after properly. Also I'd rather see sensible mileage on it -- at least 5k a year -- than garage and short-trip mileage ("only 35,000 miles on the clock"). And "one lady owner" -- be very careful. Look for signs of under-use, such as the blocked screenwash jets and faulty handbrake on the W126 I recently helped a friend obtain -- and help the vendor understand that they are bad symptoms, not good. Get it inspected by an expert anyway -- up to £200 well spent, and any faults found can be knocked off the price immediately. There are plenty of independents around who could do that for your son.

An older car is likely to be cheaper, but it in this case it may well be better; condition is far more important than age. We're talking sub-classic here anyway, so what's a few years here or there?
M.Benz Quality Question - chukter
Thank you Aprilla & Roger for your informative replies, - from what you are both saying, it would seem prudent to take some time searching out a decent 1995 or earlier 320 with the 104 engine and non water based paint.

The problem mentioned regarding the handbrake on the W126, would that also be applicable to the R129 or is that a totally different concept..??

Thanks once again.

Value my car