Mercedes' entry-level "four-door coupe" with striking design. The M270 1.6L turbo is reasonably reliable when maintained, but timing chain wear around 80,000-120,000 km is common. The 7G-DCT dual-clutch transmission can be jerky in traffic and has known mechatronics issues. Electrical gremlins (infotainment freezing, sensors), thermostat failures, and turbo wastegate actuator problems appear frequently. Avoid cars without full service history - this engine needs regular oil changes with MB-approved synthetic. Check carefully for water damage from panoramic sunroof drain blockages. More affordable to maintain than C-Class, but still requires Mercedes dealer or specialist knowledge.
The M270 timing chain wears rapidly with a typical lifespan of 80,000-120,000 km. The tensioner has a release valve that weakens over time, allowing oil pressure to bleed off overnight. This results in a distinctive rattle for 1-30 seconds on cold start. If you hear rattle lasting more than a few seconds, the chain, guides, tensioner, and sprockets all need replacing. European dealerships quote around €1,000-1,500 for timing chain replacement including labor; independent specialists charge €800-1,200. Ignoring this leads to chain skip and catastrophic valve/piston contact. Always start engine completely cold when inspecting - no exceptions.
7G-DCT transmission jerky shifts€1,500 - €3,500
Dual-clutch transmission jerky at low speeds, mechatronics failures common · more· less
The 7G-DCT dual-clutch transmission in the CLA is known for jerky shifting, especially during downshifts between 2nd-3rd gear and from standstill in traffic. Software updates help but don't eliminate the issue - this is inherent to DCT design without torque converter. More serious problems include TCM conductor plate failures causing rough shifting and intermittent gear engagement. Mechatronics unit refurbishment costs €1,500-2,000; complete transmission replacement reaches €3,000-3,500. Some level of jerkiness is normal, but if it's getting worse, check DCT fluid level at 40°C or 75°C and consider fluid+filter change at €350-450 every 100,000 km or 5 years. Manual transmission CLAs (rare) are significantly more reliable.
Thermostat housing leak€700 - €1,400
Most common M270 issue - thermostat with integrated heater element fails · more· less
This is the single most common M270 engine problem. The thermostat is a complex part with integrated heating element, located at the bottom of the engine. Replacing it costs €700-900 at Mercedes dealer, €400-600 at independent specialist. To check: verify the car reaches 80°C within 10 minutes of driving from cold. If it takes longer or temperature fluctuates, thermostat is failing. Often diagnosed alongside coolant pump leaks. Due to location, labor is 4-6 hours. Use only OEM parts - aftermarket thermostats fail prematurely. Symptoms include poor cabin heating, overheating warning, or coolant warning light.
Turbo wastegate actuator failure€500 - €2,500
Actuator sticks from carbon buildup, causes limp mode and EPC light · more· less
The turbo actuator tends to stick if the car is driven too gently or only for short trips, as carbon builds up. Common error code is P029921 ("boost pressure too low"). Symptoms include sudden loss of power, EPC warning light, and limp mode - usually occurring at highway speeds, low revs, uphill. Root cause is often the wastegate vacuum diaphragm failing because it's rubber-mounted on top of the turbo where it gets very hot. Mercedes will only sell complete turbo assembly (€2,000-2,500). However, specialists can replace just the actuator for €500-600, or you can DIY with a €40-50 actuator from aftermarket sources if mechanically confident. Using premium fuel and occasional spirited driving (Italian tune-up) helps prevent carbon buildup. Test drive must include highway speeds to heat up turbo system.
Camshaft adjuster failure€1,200 - €3,300
Solenoid or full adjuster fails, causes rough running and check engine light · more· less
Camshaft adjuster solenoid failure is one of the most common M270 problems. The solenoid magnets alone are quick to replace (€50 each, 5 minutes labor), but if the full adjusters are worn, you're looking at €1,200 at independent specialists or up to €3,300 at dealers for both intake and exhaust adjusters. Symptoms include rough idle, poor acceleration, and check engine light. The official Mercedes procedure requires multiple special tools, increasing labor cost. If under warranty, Mercedes covers this through service bulletin. Use only OEM parts - aftermarket quality is poor and you'll be doing the job twice. Typically occurs before 100,000 km.
Infotainment system freezing/glitches€200 - €3,000
COMAND screen freezes, Bluetooth disconnects, system reboots unexpectedly · more· less
Software glitches are extremely common on CLA C117. Screen freezes 30 seconds after startup, then reboots after 2 minutes of driving. Bluetooth randomly disconnects, especially when phone Bluetooth is on before starting car. First try: hold power button 10 seconds to restart, or hold CD button to reboot head unit. Check for software updates at dealer - there are service bulletins to correct screen issues. Sometimes caused by navigation SD card - try removing it. If updates don't fix it, dealer may need to order new COMAND head unit from Germany (€1,000-3,000 for replacement). Warranty typically doesn't cover software issues on older cars. Independent shops can sometimes repair COMAND for €500-800 with refurbished units.
Panoramic sunroof drain blockage€100 - €1,800
Drain tubes clog with debris, water leaks into cabin causing damage · more· less
Clogged sunroof drain tubes are a common CLA problem. Drain tubes channel water down the body pillars, but debris/leaves cause blockages. Water backs up and leaks into cabin under mats and carpet. Sometimes a broken bracket in the sunroof tract breaks and blocks the drain. Symptoms include water under floor mats (rear driver's side first, then front), condensation, and musty smell. Simple drain cleaning costs €100-200; if bracket is broken or extensive water damage occurred, repairs reach €1,500-1,800. Severe water damage can affect wiring harnesses and electrical systems. Prevention: open sunroof and use thin wire to clean drain openings quarterly; apply seal rejuvenating lubricant to all sunroof seals annually (€10 product adds years of life). Check under mats for dampness during inspection.
Fuel filler flap solenoid failure€150 - €400
Electric solenoid fails, fuel door won't open or opens randomly · more· less
This is a known issue on CLA, A-Class, and GLA models. Water ingress into the lock causes the circuit board to short. Solenoids corrode and bind over time. Symptoms range from door won't unlock when pushed, to opening randomly while driving, to not opening at all. There is a manual release in the trunk but it's difficult to access. Dealers are aware of this common problem and can fix it in 30 minutes under warranty. Out of warranty, solenoid replacement costs €150-250 at independent shops, €250-400 at dealer. Mercedes mobile service may carry spare solenoids. Some owners temporarily fix it by applying WD40 White Lithium Grease on the plunger mechanism, but replacement is the proper solution. Check operation during test drive.
Suspension squeaks and creaking€200 - €800
Control arm bushings, ball joints, and sway bar links wear causing noise · more· less
Creaking and squeaking from suspension is common on CLA, especially front suspension. Most common causes: control arm bushings fatigued and cracked (€300-500 to replace), dry ball joints (€200-400), sway bar end links loose or worn (€150-250), and sway bar bushings corroded (€100-200). Control arm bushings take most force during braking and cornering. Diagnostic tip: spray silicone into ball joint boot - if noise stops, that's your culprit. Jack up the car and move the wheel to isolate the noise source. Some squeaking is normal on German cars, but loud creaking over bumps indicates worn components. Use silicone-based water-resistant lubricant on all bushings as preventative maintenance. The 19-inch sport wheels and firm suspension on CLA exacerbate wear - 18-inch setup is more forgiving.
Auxiliary battery malfunction€150 - €600
Small 12V auxiliary battery fails, causes electrical warnings and start issues · more· less
The CLA has a small auxiliary battery in addition to the main battery. It supports Start/Stop, COMAND, and Keyless-Go systems. Auxiliary battery warnings are extremely common on modern Mercedes. Battery fails from short trips not allowing enough recharge time, especially in winter with heated seats/defrosters running. Symptoms include electrical warnings, infotainment glitches, and start/stop not working. Auxiliary battery replacement costs €150-250 at independent shops, €300-400 at dealers. Main alternator can also fail (€400-600 repair). Check voltage with engine running - should be 13.5-14.5V, anything below 12V indicates charging system problem. Replace auxiliary battery every 4-5 years preventatively. Keep footwell and trunk dry to prevent moisture corrosion on electrical connections.
Reasonably reliable when maintained, but not Toyota-level
The CLA 200 with M270 engine is more reliable than older Mercedes models, but still demands proper maintenance. Timing chain and thermostat are the main mechanical concerns, while electrical gremlins and DCT jerkiness are quality-of-life annoyances. Budget €500-1,000/year for unexpected repairs. Cars with full Mercedes service history are significantly more reliable than those serviced at generic shops - this engine needs MB-approved synthetic oil and proper diagnostics. Independent Mercedes specialists offer good value versus dealers.
Pre-Purchase Inspection Checklist
General checks
Service history
Complete Mercedes dealer or specialist service records essential. Verify oil changes every 15,000 km with MB-approved synthetic (MB 229.5 or 229.51 spec).
Tires
Check tread depth (minimum 3mm), age (date codes), and uneven wear. CLA wears 205/55 R16 or 225/40 R18 depending on trim.
Cold start
Must start engine completely cold. Listen carefully for timing chain rattle in first 30 seconds. Any rattle = walk away or negotiate €1,500 off.
Body condition
Check for accident damage, panel gaps, paint mismatch. CLA's low front splitter easily damaged on curbs.
Test drive
Minimum 25 minutes including highway speeds (80+ km/h) to check turbo actuator, DCT behavior when hot, and infotainment stability.
Specific for this vehicle
Cold start timing chain rattle test
Start engine completely cold (parked overnight minimum). Listen for rattle/ticking in first 30 seconds. Brief rattle (1-2 seconds) is acceptable; longer than 5 seconds indicates chain/tensioner wear. This is the most critical check.
Check engine temperature rise time
From cold start, engine should reach 80°C within 10 minutes of driving. Slower = failing thermostat. Watch temperature gauge closely.
DCT transmission behavior in traffic
Drive in stop-and-go traffic. Feel for jerkiness, especially 1st-2nd and 2nd-3rd shifts. Some jerkiness is normal, but harsh clunking or hesitation indicates mechatronics issues. Also test downshifts during engine braking.
Turbo boost test at highway speed
On highway, accelerate firmly from 80 to 120 km/h in higher gear at low revs. Car should pull smoothly. If it goes into limp mode, loses power, or shows EPC light, wastegate actuator is failing.
Check for water damage under mats
Remove all floor mats (front and rear) and press carpet firmly. Damp carpet or musty smell indicates sunroof drain blockage or past water damage. Check trunk carpets too. Reject car if damp - electrical damage follows.
Infotainment system full test
Test screen responsiveness, Bluetooth pairing, navigation (if equipped), and watch for unexpected reboots in first 5 minutes of driving. Try connecting phone before and after starting car.
Test fuel filler flap operation
Unlock car and push fuel flap - should open smoothly. If stuck or doesn't release, solenoid is failing (€150-400 repair).
Check auxiliary battery warning
Connect OBD scanner and check for auxiliary battery fault codes. Ask seller when auxiliary battery was last replaced - should be every 4-5 years.
Suspension noise check over bumps
Drive slowly over speed bumps and rough roads. Listen for creaking, clunking, or squeaking from front suspension. Test with windows down. Loud creaking indicates worn control arm bushings.
Verify service history authenticity
Use VIN to check Mercedes online service history portal. Verify oil change intervals meet MB spec (max 15,000 km or 1 year). Cars serviced only at generic shops often have hidden issues.
Takata airbag inflator (varies by production date)Verify completed
The CLA C117 had 25 recalls during its lifetime. Contact Mercedes-Benz dealer with VIN to verify all recalls completed. The steering column ground recall is particularly important (can cause inadvertent airbag deployment), as is the panoramic sunroof detachment recall. Some recalls had software updates available to address DCT jerkiness and infotainment glitches.
Warranty Status
Factory warranty (4 years / 80,000 km)Expired on all 2013-2019 models
Corrosion perforation warranty4 years, likely expired
Extended warranty available€800-1,500/year from Mercedes
All CLA C117 models (2013-2019) are outside original factory warranty. Mercedes offers extended service contracts but they're expensive and exclude many common issues (oil leaks, software problems, wear items). Independent warranty companies may offer better value, but read exclusions carefully - timing chain and thermostat often not covered as "wear items" after 100,000 km.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.