Car Model Guide/ Issues/ Carbon buildup on intake valves

Carbon buildup on intake valves

Attaches to direct-injection-petrol at component level · Turbo & intake · carried by 142 variants across 71 chassis

Overview

Carbon buildup on intake valves is a universal fault recorded against direct-injection-petrol at component level, typically from 80–120k km. It shows up as rough cold idle, slow throttle response, misfires, gradual loss of low-end response. Where it's documented, the repair runs €400–€700 (walnut blasting at an independent, costs dated 2026-07), and it can be difficult to check before you buy. 142 variants across 71 chassis in this database inherit it.

€400 – €700

walnut blasting at an independent · costs dated 2026-07

Likelihooduniversal

Typical onset80–120k km

Detectableno

Walk awayno

Evidencedocumented

What happens

Symptom. Rough cold idle, slow throttle response, misfires, gradual loss of low-end response.

Cause. Direct injection puts no fuel over the intake valves, so crankcase vapour deposits bake on undisturbed.

How to check it

Paperwork

Not visible without a borescope. Treat it as a service item that's due unless there's a receipt. It's not a fault, it's an unbudgeted maintenance cost.

On these cars the folder is most of the value.

Turbo & intakeuniversalNot detectable at viewingevidence: documented80–120k km

Every variant that carries this

Variant	Chassis	Body	Years	Risk	Good buy	Cost as % of good buy
320i N43	E90	sedan	2007–2011	R4	€3,950	14%
320i N43	E91	wagon	2007–2011	R4	€4,200	13%
320i N43	E92	coupe	2007–2011	R4	€4,550	12%
320i N43	E93	convertible	2007–2011	R4	€4,450	12%
325i N53	E90	sedan	2007–2011	R4	€5,250	10%
325i N53	E91	wagon	2007–2012	R4	€5,550	10%
325i N53	E92	coupe	2007–2013	R4	€6,050	9%
325i N53	E93	convertible	2007–2013	R4	€5,900	9%
330i N53	E90	sedan	2007–2011	R4	€6,000	9%
330i N53	E91	wagon	2007–2011	R4	€6,350	9%
330i N53	E92	coupe	2007–2011	R4	€6,900	8%
330i N53	E93	convertible	2007–2011	R4	€6,750	8%
335i N54	E90	sedan	2006–2010	R4	€7,350	7%
335i N54	E92	coupe	2006–2010	R4	€8,450	7%
335i N54	E93	convertible	2007–2010	R4	€8,250	7%
335i N55	E90	sedan	2010–2011	R3	€11,700	5%
335i N55	E92	coupe	2010–2013	R3	€13,450	4%
335i N55	E93	convertible	2010–2013	R3	€13,100	4%
2.0 TFSI CDNC	B8	sedan	2008–2012	R5	€4,300	13%
2.0 TFSI CDNC	B8 Avant	wagon	2008–2012	R5	€4,500	12%
1.8 TFSI CABB	B8	sedan	2008–2015	R4	€3,900	14%
1.8 TFSI CABB	B8 Avant	wagon	2008–2015	R4	€4,100	13%
C 180 CGI M271-EVO	W204	sedan	2011–2014	R2	€7,650	7%
C 180 CGI M271-EVO	S204	wagon	2011–2014	R2	€8,050	7%
1.4 TSI CAXA	Mk5	hatchback	2007–2009	R4	€3,300	17%
1.4 TSI CAXA	Mk6	hatchback	2009–2013	R4	€4,250	13%
2.0 FSI BLR	Mk5	hatchback	2004–2008	R3	€2,450	22%
116i N43B16	E87	hatchback	2007–2011	R3	€3,500	16%
116i N43B16	E81	hatchback	2007–2011	R3	€3,100	18%
118i N43	E87	hatchback	2007–2011	R3	€3,900	14%
118i N43	E81	hatchback	2007–2011	R3	€3,450	16%
118i N43	E82	coupe	2007–2011	R3	€4,000	14%
118i N43	E88	convertible	2008–2011	R3	€4,200	13%
120i N43	E87	hatchback	2007–2011	R3	€4,250	13%
120i N43	E81	hatchback	2007–2011	R3	€3,800	14%
120i N43	E82	coupe	2007–2011	R3	€4,400	13%
120i N43	E88	convertible	2008–2011	R3	€4,650	12%
135i N54	E82	coupe	2007–2010	R4	€9,800	6%
135i N54	E88	convertible	2008–2010	R4	€10,350	5%
135i N55	E82	coupe	2010–2013	R3	€12,600	4%
135i N55	E88	convertible	2010–2013	R3	€13,300	4%
1M N54	E82	coupe	2011–2012	R3	€50,700	1%
1.4 TFSI CAXC	8P	hatchback	2007–2013	R3	€3,300	17%
1.4 TFSI CAXC	8PA	hatchback	2007–2013	R3	€3,400	16%
1.4 TFSI CAXC	8P7	convertible	2008–2013	R3	€3,800	14%
1.8 TFSI CDAA	8P	hatchback	2007–2013	R3	€3,900	14%
1.8 TFSI CDAA	8PA	hatchback	2007–2013	R3	€4,000	14%
1.8 TFSI CDAA	8P7	convertible	2008–2013	R3	€4,500	12%
2.0 FSI BLR	8P	hatchback	2004–2008	R3	€2,800	20%
2.0 FSI BLR	8PA	hatchback	2004–2008	R3	€2,850	19%
2.0 TFSI CCZA	8P	hatchback	2008–2013	R3	€5,000	11%
2.0 TFSI CCZA	8PA	hatchback	2008–2013	R3	€5,150	11%
2.0 TFSI CCZA	8P7	convertible	2008–2013	R3	€5,300	10%
S3 CDLA	8P	hatchback	2006–2013	R3	€8,750	6%
S3 CDLA	8PA	hatchback	2006–2013	R3	€8,950	6%
E 200 CGI M271-EVO	W212	sedan	2009–2013	R3	€5,200	11%
E 200 CGI M271-EVO	S212	wagon	2009–2013	R3	€5,450	10%
E 250 CGI M271-EVO	W212	sedan	2009–2013	R3	€6,000	9%
E 250 CGI M271-EVO	S212	wagon	2009–2013	R3	€6,300	9%
E 200 M274	W212	sedan	2013–2016	R2	€8,450	7%
E 200 M274	S212	wagon	2013–2016	R2	€8,850	6%
E 250 M274	W212	sedan	2013–2016	R2	€9,600	6%
E 250 M274	S212	wagon	2013–2016	R2	€10,100	5%
E 350 CGI M272	W212	sedan	2009–2011	R3	€7,250	8%
E 350 CGI M272	S212	wagon	2009–2011	R3	€7,650	7%
E 350 M276	W212	sedan	2011–2016	R2	€10,500	5%
E 350 M276	S212	wagon	2011–2016	R2	€11,050	5%
523i N53	E60	sedan	2007–2010	R3	€4,950	11%
523i N53	E61	wagon	2007–2010	R3	€5,250	10%
535i N54	E60	sedan	2007–2010	R4	€6,850	8%
535i N54	E61	wagon	2007–2010	R4	€7,250	8%
E 280 M272	W211	sedan	2005–2009	R4	€3,150	17%
E 280 M272	S211	wagon	2005–2009	R4	€3,350	16%
2.0 TFSI BPJ	C6	sedan	2005–2011	R3	€3,450	16%
2.0 TFSI BPJ	C6 Avant	wagon	2005–2011	R3	€3,600	15%
2.8 FSI CCEA	C6	sedan	2008–2011	R3	€4,550	12%
2.8 FSI CCEA	C6 Avant	wagon	2008–2011	R3	€4,800	11%
1.4 TSI CAXA	1Z	hatchback	2008–2013	R3	€2,100	26%
1.4 TSI CAXA	1Z Combi	wagon	2008–2013	R3	€2,200	25%
1.8 TFSI CDAA	1Z	hatchback	2007–2013	R3	€2,450	22%
1.8 TFSI CDAA	1Z Combi	wagon	2007–2013	R3	€2,600	21%
vRS 2.0 TSI CCZA	1Z	hatchback	2009–2013	R3	€3,850	14%
vRS 2.0 TSI CCZA	1Z Combi	wagon	2009–2013	R3	€4,050	14%
1.4 TSI CAXA	B6	sedan	2007–2010	R3	€2,000	28%
1.4 TSI CAXA	B6 Variant	wagon	2007–2010	R3	€2,150	26%
1.8 TFSI CDAA	B6	sedan	2007–2010	R3	€2,400	23%
1.8 TFSI CDAA	B6 Variant	wagon	2007–2010	R3	€2,550	22%
2.0 EcoBoost TPBA	Mk4	hatchback	2010–2014	R3	€2,850	19%
2.0 EcoBoost TPBA	Mk4 Estate	wagon	2010–2014	R3	€3,000	18%
1.8 TFSI CDAA	3T	hatchback	2008–2015	R3	€3,350	16%
1.8 TFSI CDAA	3T Combi	wagon	2009–2015	R3	€3,550	15%
2.0 TSI CCZA	3T	hatchback	2008–2015	R3	€4,250	13%
2.0 TSI CCZA	3T Combi	wagon	2009–2015	R3	€4,500	12%
1.4 TSI CAXA	1P	hatchback	2008–2012	R3	€1,950	28%
1.8 TFSI CDAA	1P	hatchback	2007–2012	R3	€2,150	26%
Cupra 2.0 TSI CCZA	1P	hatchback	2009–2012	R3	€3,550	15%
2.5T B5254T	P3	wagon	2007–2014	R2	€4,750	12%
2.5T B5254T	P3	sedan	2010–2014	R2	€4,600	12%
2.0 Turbo A20NHT	A	hatchback	2008–2015	R3	€2,100	26%
2.0 Turbo A20NHT	A Sports Tourer	wagon	2009–2015	R3	€2,250	24%
1.2 TSI CJZA	Mk7	hatchback	2012–2017	R2	€6,500	8%
1.2 TSI CJZA	Mk7 Variant	wagon	2013–2017	R2	€6,850	8%
1.4 TSI CZEA	Mk7	hatchback	2013–2019	R2	€8,500	6%
1.4 TSI CZEA	Mk7 Variant	wagon	2013–2019	R2	€8,950	6%
GTI CHHB	Mk7	hatchback	2013–2019	R3	€12,750	4%
GTI CHHB	Mk7 Variant	wagon	2013–2019	R3	€13,400	4%
1.4 TFSI CZEA	8V	hatchback	2013–2020	R2	€10,550	5%
1.4 TFSI CZEA	8V Sportback	hatchback	2013–2020	R2	€10,950	5%
1.4 TSI CZEA	5E	hatchback	2013–2020	R2	€6,900	8%
1.4 TSI CZEA	5E Combi	wagon	2013–2020	R2	€7,300	8%
1.4 TSI CZEA	5F	hatchback	2013–2020	R2	€5,850	9%
Cupra CHHB	5F	hatchback	2014–2020	R3	€9,800	6%
1.0 EcoBoost M1DA	Mk3	hatchback	2012–2018	R3	€2,500	22%
1.0 EcoBoost M1DA	Mk3 Estate	wagon	2012–2018	R3	€2,650	21%
1.6 THP EP6	508	sedan	2011–2018	R4	€1,750	31%
1.6 THP EP6	508 SW	wagon	2011–2018	R4	€1,850	30%
Cooper S N14	R56	hatchback	2006–2010	R4	€5,500	10%
xDrive35i N55	E70	SUV	2010–2013	R3	€16,100	3%
2.0 TFSI CDNC	8R	SUV	2008–2012	R4	€9,000	6%
ML 350 M272	W164	SUV	2005–2011	R4	€6,600	8%
1.4 TSI CAXA	5N	SUV	2007–2016	R4	€6,600	8%
2.0 TSI CCZA	5N	SUV	2008–2011	R3	€7,750	7%
1.2 TSI CBZB	6R	hatchback	2010–2014	R4	€5,500	10%
1.2 TSI CBZB	5J	hatchback	2010–2014	R4	€4,800	11%
1.2 TSI CBZB	5J Combi	wagon	2010–2014	R4	€5,050	11%
1.4 TSI CAXA	5L	SUV	2009–2017	R4	€6,500	8%
1.2 TSI CBZB	6J	hatchback	2010–2015	R4	€4,400	13%
1.2 TSI CBZB	6J ST	wagon	2010–2015	R4	€4,600	12%
1.0 EcoBoost M1DA	B299	hatchback	2012–2017	R4	€6,400	9%
1.6 DIG-T MR16DDT	F15	crossover	2010–2019	R3	€8,250	7%
328i N20	F30	sedan	2012–2015	R4	€11,000	5%
328i N20	F31	wagon	2012–2015	R4	€11,700	5%
335i N55	F30	sedan	2012–2015	R3	€13,250	4%
335i N55	F31	wagon	2012–2015	R3	€14,050	4%
C 200 M274	W205	sedan	2014–2018	R3	€12,500	4%
C 200 M274	S205	wagon	2014–2018	R3	€13,000	4%
1.4 TSI ACT CZEA	3G	sedan	2014–2019	R3	€10,250	5%
1.4 TSI ACT CZEA	3G Variant	wagon	2014–2019	R3	€10,800	5%
1.4 TSI CAXA	1T	MPV	2007–2015	R4	€4,700	12%
1.6 THP EP6	T7	hatchback	2007–2013	R4	€2,600	21%
2.0 SkyActiv-G PE-VPS	KE	SUV	2012–2017	R1	€10,900	5%
2.5 T5 B5254T	C394	SUV	2009–2012	R3	€5,350	10%

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.