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 67 variants across 19 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. 67 variants across 19 chassis in this database inherit it.

€400 – €700
walnut blasting at an independent · costs dated
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: documented80120k km

Every variant that carries this

VariantChassisBodyYearsRiskGood buyCost as % of good buy
320i N43E90sedan2007–2011R4€3,95014%
320i N43E91wagon2007–2011R4€4,20013%
320i N43E92coupe2007–2011R4€4,55012%
320i N43E93convertible2007–2011R4€4,45012%
325i N53E90sedan2007–2011R4€5,25010%
325i N53E91wagon2007–2012R4€5,55010%
325i N53E92coupe2007–2013R4€6,0509%
325i N53E93convertible2007–2013R4€5,9009%
330i N53E90sedan2007–2011R4€6,0009%
330i N53E91wagon2007–2011R4€6,3509%
330i N53E92coupe2007–2011R4€6,9008%
330i N53E93convertible2007–2011R4€6,7508%
335i N54E90sedan2006–2010R4€7,3507%
335i N54E92coupe2006–2010R4€8,4507%
335i N54E93convertible2007–2010R4€8,2507%
335i N55E90sedan2010–2011R3€11,7005%
335i N55E92coupe2010–2013R3€13,4504%
335i N55E93convertible2010–2013R3€13,1004%
2.0 TFSI CDNCB8sedan2008–2012R5€4,30013%
2.0 TFSI CDNCB8 Avantwagon2008–2012R5€4,50012%
1.8 TFSI CABBB8sedan2008–2015R4€3,90014%
1.8 TFSI CABBB8 Avantwagon2008–2015R4€4,10013%
C 180 CGI M271-EVOW204sedan2011–2014R2€7,6507%
C 180 CGI M271-EVOS204wagon2011–2014R2€8,0507%
1.4 TSI CAXAMk5hatchback2007–2009R4€3,30017%
1.4 TSI CAXAMk6hatchback2009–2013R4€4,25013%
2.0 FSI BLRMk5hatchback2004–2008R3€2,45022%
116i N43B16E87hatchback2007–2011R3€3,50016%
116i N43B16E81hatchback2007–2011R3€3,10018%
118i N43E87hatchback2007–2011R3€3,90014%
118i N43E81hatchback2007–2011R3€3,45016%
118i N43E82coupe2007–2011R3€4,00014%
118i N43E88convertible2008–2011R3€4,20013%
120i N43E87hatchback2007–2011R3€4,25013%
120i N43E81hatchback2007–2011R3€3,80014%
120i N43E82coupe2007–2011R3€4,40013%
120i N43E88convertible2008–2011R3€4,65012%
135i N54E82coupe2007–2010R4€9,8006%
135i N54E88convertible2008–2010R4€10,3505%
135i N55E82coupe2010–2013R3€12,6004%
135i N55E88convertible2010–2013R3€13,3004%
1M N54E82coupe2011–2012R3€50,7001%
1.4 TFSI CAXC8Phatchback2007–2013R3€3,30017%
1.4 TFSI CAXC8PAhatchback2007–2013R3€3,40016%
1.4 TFSI CAXC8P7convertible2008–2013R3€3,80014%
1.8 TFSI CDAA8Phatchback2007–2013R3€3,90014%
1.8 TFSI CDAA8PAhatchback2007–2013R3€4,00014%
1.8 TFSI CDAA8P7convertible2008–2013R3€4,50012%
2.0 FSI BLR8Phatchback2004–2008R3€2,80020%
2.0 FSI BLR8PAhatchback2004–2008R3€2,85019%
2.0 TFSI CCZA8Phatchback2008–2013R3€5,00011%
2.0 TFSI CCZA8PAhatchback2008–2013R3€5,15011%
2.0 TFSI CCZA8P7convertible2008–2013R3€5,30010%
S3 CDLA8Phatchback2006–2013R3€8,7506%
S3 CDLA8PAhatchback2006–2013R3€8,9506%
E 200 CGI M271-EVOW212sedan2009–2013R3€5,20011%
E 200 CGI M271-EVOS212wagon2009–2013R3€5,45010%
E 250 CGI M271-EVOW212sedan2009–2013R3€6,0009%
E 250 CGI M271-EVOS212wagon2009–2013R3€6,3009%
E 200 M274W212sedan2013–2016R2€8,4507%
E 200 M274S212wagon2013–2016R2€8,8506%
E 250 M274W212sedan2013–2016R2€9,6006%
E 250 M274S212wagon2013–2016R2€10,1005%
E 350 CGI M272W212sedan2009–2011R3€7,2508%
E 350 CGI M272S212wagon2009–2011R3€7,6507%
E 350 M276W212sedan2011–2016R2€10,5005%
E 350 M276S212wagon2011–2016R2€11,0505%

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.