Car Model Guide/ Issues/ Panoramic sunroof drain blockage

Panoramic sunroof drain blockage

Attaches to W212/S212 at chassis level · Body & corrosion · carried by 20 variants across 2 chassis

Overview

Panoramic sunroof drain blockage is a common fault recorded against W212/S212 at chassis level, typically from 80–200k km. It shows up as wet front footwells and carpets and damp A-pillars after rain, with soaked module connectors as the secondary risk. Where it's documented, the repair runs €50–€400 (€50–150 to clear the drains; more if carpets or modules are damaged, costs dated 2026-07), and it can be checked before you buy. 20 variants across 2 chassis in this database inherit it.

€50 – €400

€50–150 to clear the drains; more if carpets or modules are damaged · costs dated 2026-07

Likelihoodcommon

Typical onset80–200k km

Detectableyes

Walk awayno

Evidencedocumented

What happens

Symptom. Wet front footwells and carpets and damp A-pillars after rain, with soaked module connectors as the secondary risk.

Cause. The sunroof drain channels clog with debris and water backs up and overflows into the cabin. The cause is consistent; the cost jumps if carpets or modules are soaked.

How to check it

Static checks

Lift the footwell carpets to feel for damp, and pour a cup of water into the front sunroof channel to confirm it drains quickly.

Engine off, ideally on a lift.

Body & corrosioncommonDetectable at viewingevidence: documented80–200k km

Every variant that carries this

Variant	Chassis	Body	Years	Risk	Good buy	Cost as % of good buy
E 220 CDI OM651	W212	sedan	2009–2016	R3	€6,300	4%
E 220 CDI OM651	S212	wagon	2009–2016	R3	€6,650	3%
E 200 CDI OM651	W212	sedan	2010–2016	R3	€5,500	4%
E 200 CDI OM651	S212	wagon	2010–2016	R3	€5,800	4%
E 250 CDI OM651	W212	sedan	2009–2016	R3	€7,300	3%
E 250 CDI OM651	S212	wagon	2009–2016	R3	€7,700	3%
E 350 CDI OM642	W212	sedan	2009–2016	R3	€8,750	3%
E 350 CDI OM642	S212	wagon	2009–2016	R3	€9,200	2%
E 200 CGI M271-EVO	W212	sedan	2009–2013	R3	€5,200	4%
E 200 CGI M271-EVO	S212	wagon	2009–2013	R3	€5,450	4%
E 250 CGI M271-EVO	W212	sedan	2009–2013	R3	€6,000	4%
E 250 CGI M271-EVO	S212	wagon	2009–2013	R3	€6,300	4%
E 200 M274	W212	sedan	2013–2016	R2	€8,450	3%
E 200 M274	S212	wagon	2013–2016	R2	€8,850	3%
E 250 M274	W212	sedan	2013–2016	R2	€9,600	2%
E 250 M274	S212	wagon	2013–2016	R2	€10,100	2%
E 350 CGI M272	W212	sedan	2009–2011	R3	€7,250	3%
E 350 CGI M272	S212	wagon	2009–2011	R3	€7,650	3%
E 350 M276	W212	sedan	2011–2016	R2	€10,500	2%
E 350 M276	S212	wagon	2011–2016	R2	€11,050	2%

The last column is the point. The same repair is an inconvenience on one variant and a reason to scrap the car on another. A failure costing a quarter of the vehicle's value changes the purchase decision regardless of how rare it is.