Car Model Guide/ Issues/ Coolant expansion tank cracking

Coolant expansion tank cracking

Attaches to E9X at chassis level · Cooling · carried by 171 variants across 19 chassis

Overview

Coolant expansion tank cracking is a common fault recorded against E9X at chassis level, typically from 90–200k km. It shows up as coolant smell after a drive, slow unexplained loss of coolant, crusty residue around the tank seams. Where it's documented, the repair runs €120–€250 (tank and cap at an independent, costs dated 2026-07), and it can be checked before you buy. 171 variants across 19 chassis in this database inherit it.

€120 – €250

tank and cap at an independent · costs dated 2026-07

Likelihoodcommon

Typical onset90–200k km

Detectableyes

Walk awayno

Evidencedocumented

What happens

Symptom. Coolant smell after a drive, slow unexplained loss of coolant, crusty residue around the tank seams.

Cause. The plastic tank goes brittle with age and splits, usually at a seam or around the level sensor.

How to check it

Static checks

Look at the tank with the engine warm, dried coolant leaves a white or pink crust. Cheap to fix, but it tells you how the car has been maintained.

Engine off, ideally on a lift.

CoolingcommonDetectable at viewingevidence: documented90–200k km

Every variant that carries this

Variant	Chassis	Body	Years	Risk	Good buy	Cost as % of good buy
318i N46	E90	sedan	2005–2011	R3	€3,100	6%
318i N46	E91	wagon	2005–2011	R3	€3,300	6%
320i N46	E90	sedan	2005–2007	R3	€3,400	5%
320i N46	E91	wagon	2005–2007	R3	€3,600	5%
320i N43	E90	sedan	2007–2011	R4	€3,950	5%
320i N43	E91	wagon	2007–2011	R4	€4,200	4%
320i N43	E92	coupe	2007–2011	R4	€4,550	4%
320i N43	E93	convertible	2007–2011	R4	€4,450	4%
323i N52	E90	sedan	2005–2007	R2	€4,050	5%
323i N52	E91	wagon	2005–2007	R2	€4,300	4%
323i N52	E92	coupe	2006–2007	R2	€4,650	4%
325i N52	E90	sedan	2005–2007	R2	€4,750	4%
325i N52	E91	wagon	2005–2007	R2	€5,050	4%
325i N52	E92	coupe	2006–2007	R2	€5,450	3%
325i N52	E93	convertible	2007	R2	€5,350	3%
325i N53	E90	sedan	2007–2011	R4	€5,250	4%
325i N53	E91	wagon	2007–2012	R4	€5,550	3%
325i N53	E92	coupe	2007–2013	R4	€6,050	3%
325i N53	E93	convertible	2007–2013	R4	€5,900	3%
328i N52	E90	sedan	2006–2011	R2	€5,150	4%
328i N52	E91	wagon	2006–2012	R2	€5,450	3%
328i N52	E92	coupe	2006–2013	R2	€5,950	3%
328i N52	E93	convertible	2007–2013	R2	€5,750	3%
330i N52	E90	sedan	2005–2007	R2	€5,600	3%
330i N52	E91	wagon	2005–2007	R2	€5,950	3%
330i N52	E92	coupe	2006–2007	R2	€6,450	3%
330i N53	E90	sedan	2007–2011	R4	€6,000	3%
330i N53	E91	wagon	2007–2011	R4	€6,350	3%
330i N53	E92	coupe	2007–2011	R4	€6,900	3%
330i N53	E93	convertible	2007–2011	R4	€6,750	3%
335i N54	E90	sedan	2006–2010	R4	€7,350	3%
335i N54	E92	coupe	2006–2010	R4	€8,450	2%
335i N54	E93	convertible	2007–2010	R4	€8,250	2%
335i N55	E90	sedan	2010–2011	R3	€11,700	2%
335i N55	E92	coupe	2010–2013	R3	€13,450	1%
335i N55	E93	convertible	2010–2013	R3	€13,100	1%
316d N47	E90	sedan	2009–2011	R5	€4,200	4%
316d N47	E91	wagon	2009–2011	R5	€4,450	4%
318d N47	E90	sedan	2007–2011	R5	€4,100	5%
318d N47	E91	wagon	2007–2011	R5	€4,350	4%
320d M47	E90	sedan	2005–2007	R3	€3,800	5%
320d M47	E91	wagon	2005–2007	R3	€4,050	5%
320d N47	E90	sedan	2007–2011	R5	€4,400	4%
320d N47	E91	wagon	2007–2012	R5	€4,650	4%
320d N47	E92	coupe	2007–2013	R5	€5,050	4%
320d N47	E93	convertible	2007–2013	R5	€4,950	4%
325d M57	E90	sedan	2006–2010	R2	€5,200	4%
325d M57	E91	wagon	2006–2010	R2	€5,500	3%
325d M57	E92	coupe	2006–2010	R2	€6,000	3%
325d N57	E90	sedan	2010–2011	R3	€7,200	3%
325d N57	E91	wagon	2010–2012	R3	€7,650	2%
325d N57	E92	coupe	2010–2013	R3	€8,300	2%
330d M57	E90	sedan	2005–2008	R2	€5,950	3%
330d M57	E91	wagon	2005–2008	R2	€6,300	3%
330d M57	E92	coupe	2006–2008	R2	€6,850	3%
330d M57	E93	convertible	2007–2008	R2	€6,700	3%
330d N57	E90	sedan	2008–2011	R3	€8,500	2%
330d N57	E91	wagon	2008–2012	R3	€9,050	2%
330d N57	E92	coupe	2008–2013	R3	€9,000	2%
330d N57	E93	convertible	2008–2013	R3	€8,750	2%
335d M57	E90	sedan	2006–2010	R3	€6,900	3%
335d M57	E92	coupe	2006–2010	R3	€7,950	2%
M3 S65	E90	sedan	2007–2011	R4	€35,700	1%
M3 S65	E92	coupe	2007–2013	R4	€35,000	1%
M3 S65	E93	convertible	2007–2013	R4	€30,800	1%
2.0 TFSI CDNC	B8	sedan	2008–2012	R5	€4,300	4%
2.0 TFSI CDNC	B8 Avant	wagon	2008–2012	R5	€4,500	4%
2.0 TFSI CNCD	B8	sedan	2012–2015	R3	€8,200	2%
2.0 TFSI CNCD	B8 Avant	wagon	2012–2016	R3	€8,600	2%
2.0 TDI CJCA	B8	sedan	2008–2015	R3	€5,200	4%
2.0 TDI CJCA	B8 Avant	wagon	2008–2016	R3	€5,500	3%
3.0 TDI CCWA	B8	sedan	2008–2015	R4	€7,500	2%
3.0 TDI CCWA	B8 Avant	wagon	2008–2016	R4	€7,900	2%
1.8 TFSI CABB	B8	sedan	2008–2015	R4	€3,900	5%
1.8 TFSI CABB	B8 Avant	wagon	2008–2015	R4	€4,100	5%
C 220 CDI OM651	W204	sedan	2009–2014	R3	€5,700	3%
C 220 CDI OM651	S204	wagon	2009–2014	R3	€6,000	3%
C 180 Kompressor M271-KOMP	W204	sedan	2007–2011	R5	€3,450	5%
C 180 Kompressor M271-KOMP	S204	wagon	2008–2011	R5	€3,650	5%
C 180 CGI M271-EVO	W204	sedan	2011–2014	R2	€7,650	2%
C 180 CGI M271-EVO	S204	wagon	2011–2014	R2	€8,050	2%
C 320 CDI OM642	W204	sedan	2007–2011	R3	€6,600	3%
C 320 CDI OM642	S204	wagon	2008–2011	R3	€6,950	3%
1.9 TDI BKC	Mk5	hatchback	2003–2009	R2	€2,000	9%
1.6 TDI CAYC	Mk6	hatchback	2009–2013	R3	€5,350	3%
1.4 TSI CAXA	Mk5	hatchback	2007–2009	R4	€3,300	6%
1.4 TSI CAXA	Mk6	hatchback	2009–2013	R4	€4,250	4%
2.0 FSI BLR	Mk5	hatchback	2004–2008	R3	€2,450	8%
116i N45B16	E87	hatchback	2004–2007	R2	€2,700	7%
116i N43B16	E87	hatchback	2007–2011	R3	€3,500	5%
116i N43B16	E81	hatchback	2007–2011	R3	€3,100	6%
118i N46	E87	hatchback	2004–2007	R2	€2,900	6%
118i N43	E87	hatchback	2007–2011	R3	€3,900	5%
118i N43	E81	hatchback	2007–2011	R3	€3,450	5%
118i N43	E82	coupe	2007–2011	R3	€4,000	5%
118i N43	E88	convertible	2008–2011	R3	€4,200	4%
120i N46	E87	hatchback	2004–2007	R2	€3,250	6%
120i N43	E87	hatchback	2007–2011	R3	€4,250	4%
120i N43	E81	hatchback	2007–2011	R3	€3,800	5%
120i N43	E82	coupe	2007–2011	R3	€4,400	4%
120i N43	E88	convertible	2008–2011	R3	€4,650	4%
125i N52	E82	coupe	2008–2013	R2	€7,000	3%
125i N52	E88	convertible	2008–2013	R2	€7,400	3%
130i N52	E87	hatchback	2005–2011	R2	€7,000	3%
130i N52	E81	hatchback	2007–2011	R2	€6,800	3%
135i N54	E82	coupe	2007–2010	R4	€9,800	2%
135i N54	E88	convertible	2008–2010	R4	€10,350	2%
135i N55	E82	coupe	2010–2013	R3	€12,600	1%
135i N55	E88	convertible	2010–2013	R3	€13,300	1%
1M N54	E82	coupe	2011–2012	R3	€50,700	0%
116d N47	E87	hatchback	2009–2011	R4	€4,050	5%
116d N47	E81	hatchback	2009–2011	R4	€3,600	5%
118d M47	E87	hatchback	2004–2007	R2	€3,200	6%
118d N47	E87	hatchback	2007–2011	R4	€4,600	4%
118d N47	E81	hatchback	2007–2012	R4	€4,100	5%
118d N47	E82	coupe	2007–2013	R4	€4,700	4%
118d N47	E88	convertible	2008–2013	R4	€4,950	4%
120d M47	E87	hatchback	2004–2007	R2	€3,550	5%
120d N47	E87	hatchback	2007–2011	R4	€5,150	4%
120d N47	E81	hatchback	2007–2012	R4	€4,600	4%
120d N47	E82	coupe	2007–2013	R4	€5,250	4%
120d N47	E88	convertible	2008–2013	R4	€5,550	3%
123d N47S	E87	hatchback	2007–2011	R4	€6,450	3%
123d N47S	E81	hatchback	2007–2012	R4	€5,750	3%
123d N47S	E82	coupe	2007–2013	R4	€6,650	3%
123d N47S	E88	convertible	2008–2013	R4	€6,950	3%
1.6 BSE	8P	hatchback	2003–2010	R2	€2,350	8%
1.6 BSE	8PA	hatchback	2004–2010	R2	€2,400	8%
1.4 TFSI CAXC	8P	hatchback	2007–2013	R3	€3,300	6%
1.4 TFSI CAXC	8PA	hatchback	2007–2013	R3	€3,400	5%
1.4 TFSI CAXC	8P7	convertible	2008–2013	R3	€3,800	5%
1.8 TFSI CDAA	8P	hatchback	2007–2013	R3	€3,900	5%
1.8 TFSI CDAA	8PA	hatchback	2007–2013	R3	€4,000	5%
1.8 TFSI CDAA	8P7	convertible	2008–2013	R3	€4,500	4%
2.0 FSI BLR	8P	hatchback	2004–2008	R3	€2,800	7%
2.0 FSI BLR	8PA	hatchback	2004–2008	R3	€2,850	6%
2.0 TFSI CCZA	8P	hatchback	2008–2013	R3	€5,000	4%
2.0 TFSI CCZA	8PA	hatchback	2008–2013	R3	€5,150	4%
2.0 TFSI CCZA	8P7	convertible	2008–2013	R3	€5,300	3%
S3 CDLA	8P	hatchback	2006–2013	R3	€8,750	2%
S3 CDLA	8PA	hatchback	2006–2013	R3	€8,950	2%
1.9 TDI BKC	8P	hatchback	2003–2010	R2	€2,450	8%
1.9 TDI BKC	8PA	hatchback	2004–2010	R2	€2,500	7%
2.0 TDI BKD	8P	hatchback	2003–2008	R3	€3,300	6%
2.0 TDI BKD	8PA	hatchback	2004–2008	R3	€3,400	5%
2.0 TDI CBAB	8P	hatchback	2008–2013	R4	€4,700	4%
2.0 TDI CBAB	8PA	hatchback	2008–2013	R4	€4,800	4%
2.0 TDI CBAB	8P7	convertible	2008–2013	R4	€4,950	4%
1.6 TDI CAYC	8P	hatchback	2009–2013	R3	€4,150	4%
1.6 TDI CAYC	8PA	hatchback	2009–2013	R3	€4,250	4%
1.6 TDI CAYC	8P7	convertible	2009–2013	R3	€4,400	4%
E 220 CDI OM651	W212	sedan	2009–2016	R3	€6,300	3%
E 220 CDI OM651	S212	wagon	2009–2016	R3	€6,650	3%
E 200 CDI OM651	W212	sedan	2010–2016	R3	€5,500	3%
E 200 CDI OM651	S212	wagon	2010–2016	R3	€5,800	3%
E 250 CDI OM651	W212	sedan	2009–2016	R3	€7,300	3%
E 250 CDI OM651	S212	wagon	2009–2016	R3	€7,700	2%
E 350 CDI OM642	W212	sedan	2009–2016	R3	€8,750	2%
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	3%
E 250 CGI M271-EVO	W212	sedan	2009–2013	R3	€6,000	3%
E 250 CGI M271-EVO	S212	wagon	2009–2013	R3	€6,300	3%
E 200 M274	W212	sedan	2013–2016	R2	€8,450	2%
E 200 M274	S212	wagon	2013–2016	R2	€8,850	2%
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	2%
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.