Windscreen bonding not fit for purpose.

[Tamla]

Hi, I'm new to the forum. Bought my 2015 CLS 350 in Nov 2020. In Feb this year, EML came on and after inspection at the specialists, the bonding on the front windscreen has failed after only 8 years. Water has leaked in from the top centre of the screen, down the A post into the footwell and contaminated the wiring loom, Nox sensors etc. Original windscreen from new, MB 'goodwill team' don't want to know and the dealership JCT600 Doncaster have quoted £7000 to repair not including windscreen replacement if existing one breaks when taken out so potentially looking at an eight grand bill. Obviously out of warranty. Still waiting for motor ombudsman to get back to me since Feb this year. My credit card company is on the case with section 75 consumer credit act 1974. Been sold a car with underlying issues so don't want to pay such a huge bill when it's a manufacturer fault. Classic case of big company trying to trample over the little person. Possibly going to small claims court if it doesn't get resolved. Very, very frustrating, lots of sleepless nights. Any advice would be appreciated and thanks in advance.

 

[Blobcat]

Hello and welcome,

One of the problems you'll face is that the vast majority of Mercedes windscreens and the bonding are fit for purpose - You say it's the original screen, although did it have a replacement screen in the first 5 years before your ownership? (Owners can get original screens as a replacement, although most just go with whatever screen replacement company provide)

Nox sensor failures are common, they're also under the car in the exhaust so I'm confused how a windscreen bonding issue could cause Nox failure

I'd be going to a Mercedes specialist Independent, wouldn't go near a main dealer with a 9 year old car

 

[sonic]

Have you looked at your windscreen insurance cover?

 

[Tamla]

Have you looked at your windscreen insurance cover?

Hi, no not yet. Don't want to get anything done yet in case it invalidates any impending case. Been covering the gap with a screen cover since the leak was discovered.

 

[Tamla]

Hello and welcome,

One of the problems you'll face is that the vast majority of Mercedes windscreens and the bonding are fit for purpose - You say it's the original screen, although did it have a replacement screen in the first 5 years before your ownership? (Owners can get original screens as a replacement, although most just go with whatever screen replacement company provide)

Nox sensor failures are common, they're also under the car in the exhaust so I'm confused how a windscreen bonding issue could cause Nox failure

I'd be going to a Mercedes specialist Independent, wouldn't go near a main dealer with a 9 year old car

Hi thanks for your response. Like I said, I took the car to the specialist in the first instance who sourced the problem, been going to them since purchase. Car been on both specialist diagnostic machine and JCT dealership diagnostics and although I am aware that owners can buy original, both are certain it's the original screen due to lettering, logos in corners of screen.

Leak has gone into the footwell which has contaminated wiring loom and somehow contaminated wiring going to NOX sensor. Specialists showed me this whilst the car was on the ramp. The specialists have been established for over 40 years with excellent reviews.

In fact, when I first purchased the car I took it for a health check to the same specialist for peace of mind and it came to light that the car should have had a gearbox service, various filters changed, work that had been missed/not carried out etc which would have amounted to just under £1000 bill! When I challenged JCT600 dealership about this, their response was "These things happen!" Car was made correct under warranty. Been going to the same specialist ever since because of their honesty.

Forgot to mention, I bought the car from JCT600 Doncaster in the first place.

 

[KennyN]

Is the car running , if so are there any fault lights ?

How does a wiring loom get contaminated , plugs maybe get corroded at their connection but unless the connected component is fired then any moisture could be dealt with.

K

 

[peterws1957]

It would be interesting to see how JCT have arrived at their price of £7k. Knowing MB dealer prices for any work I strongly suspect that there will be a much more economic way of carrying out the repairs. I would strongly advise looking into the costs further and getting more info as to what components are being replaced. Can the whole area be simply carefully dried out?
If that much water has entered the car would the carpets not have been saturated and condensation have been a problem as a result. Did not your specialist comment on this during their services? As I see it the problem is going to be proving that the issue was a manufacturing fault or present at the time of purchase. If the latter then surely the resultant damage would have come to light earlier. If it's only started occurring on a 9 year old car I suspect you will find that you don't have a case.

MB's seem to have a problem with leaks into the cabin, I've never known cars with such common issues. It's a frustrating predicament and I hope you make headway. Unfortunately I've found Ombudsman's services to be useless. Best of luck Tamla.