R129 rear subframe corrosion (and SRS light)

[usernothername]

Hello all,
Still on my mission to purchase an R129 and am now looking at a 320. While I'd still prefer a 500, other aspects of the spec are important so maybe will compromise on a 320 for now then upgrade to a 500 in future.
This one has had quite a lot of advisories on the last few years' MOTs which is always a bit of a concern as it suggests to me a lack of care. But could just be a very fussy tester, I suppose. One is more concerning that others: "Rear Sub-frame corroded but not seriously weakened".
I'd heard about this being a weakness on the R129 and saw the SL shop's article about it. Assuming they are all going to have a degree of rust at this age, so not sure how to judge how much is too much. Does anyone have examples of when it's going to be a problem? I've attached a couple of (poor quality, sorry) photos I took. Might try and get it on a ramp to have a closer look later this week.
I'm guessing here these might be the points the MOT tester is noting.

 

[usernothername]

The other thing was the SRS warning light is constantly on. I was thinking maybe a switch or sensor on one of the seats or seatbelts, maybe an easy ish fix. But coincidently (or not?) the MOT from 2013 to 2019 had an advisory "Supplementary Restraint System warning lamp does not illuminate"

 

[Wearsafoxhat]

There are still plenty of good ones around….

 

[Blobcat]

That rust you’ve arrowed doesn’t look good… probably rusting from the inside so a couple of good taps and a large hole could well appear…
As per above I’d keep looking

 

[usernothername]

Hmm yeah I thought maybe as much. Shame, it has oxblood interior which seems quite rare and looks great. I’d probably not like it so much after the rear end rusted off

 

[malcolm E53 AMG]

Re the condition of the rear subframe a bit of a lottery with a car of this age and such a lot of variables ie quality of the metal and cavity rustproofing at manufacture so I’d keep looking the main thing is knowing what to look for rusting from inside out is the worst scenario I’d walk away

 

[usernothername]

Thank you, appreciate the advice

 

[usernothername]

Hi all, how are other people managing the corrosion (or risk of corrosion) on the rear subframe? From what I can see they all have some and will eventually worsen if the car is used in UK weather or kept outside. Is there anything that can be done - like rub down and wax oil / etc? The SL shop strip back and shot blast and fully recondition apparently cost around £7k which would possibly effectively write off most lower end models. Cheers

 

[Mal-C]

Hi, I've used Lanoguard which was recommended by my MOT guy. Really easy to apply (easier than waxoil IMO) I've owned my 2001 SL320 for 9 years and it's been amazing. I know the big V8's fetch a premium but I've been more than happy with the performance of the V6 320. What's your budget? I'm selling mine as I now have a CLK because I wanted 4 seats. I'm in Wolverhampton. As I said it's a 2001 SL320 with 76500 miles, full service history excellent all round with electric everything as usual. Let me know if interested to take a look. PS I had an SRS light issue which was the unit under the passenger seat. Cost around £400 to fix.

 

[usernothername]

Hi, I've used Lanoguard which was recommended by my MOT guy. Really easy to apply (easier than waxoil IMO) I've owned my 2001 SL320 for 9 years and it's been amazing. I know the big V8's fetch a premium but I've been more than happy with the performance of the V6 320. What's your budget? I'm selling mine as I now have a CLK because I wanted 4 seats. I'm in Wolverhampton. As I said it's a 2001 SL320 with 76500 miles, full service history excellent all round with electric everything as usual. Let me know if interested to take a look. PS I had an SRS light issue which was the unit under the passenger seat. Cost around £400 to fix.

Hello mate sorry for the slow reply and thanks for the info re Lanoguard. Can you put that on metal with surface corrosion after just a rub down, or does it need to be prepped back to clean metal? I’ve still not bought one so yeah I might be interested- DM me maybe with details / pics? Thanks

 

[Mal-C]

Hello mate sorry for the slow reply and thanks for the info re Lanoguard. Can you put that on metal with surface corrosion after just a rub down, or does it need to be prepped back to clean metal? I’ve still not bought one so yeah I might be interested- DM me maybe with details / pics? Thanks

Hi, also sorry for late reply, I'm not getting notifications. My car is sold now. Lanoguard is made to go over surface rust so no need to clean back to bare metal. they actually recommend blasting it all with a pressure washer then let it dry. Good luck finding a good SL you will love it.