Mercedes Benz CLA 45 AMG Engine ReplacementCompare Prices & Get Quotes

A Mercedes CLA 45 AMG replacement engine typically costs between £2,800 for a used M133 unit and £11,000 for a fully rebuilt M139 engine. Specialist fitting adds £800-£1,500 due to the complexity of the 4MATIC+ system.

• Used M133/M139 engines: £2,800-£6,500 depending on mileage and condition
• Rebuilt M133 units: £5,500-£8,000 supply only
• Rebuilt M139 units: £7,000-£11,000 supply only
• Specialist fitting adds £800-£1,500; dealer labour is significantly higher
• 12-month warranty included on all rebuilt units through EnginesMarket

The CLA 45 AMG's M133 and M139 engines are high-performance units with known weak points. The M133 (2013-2019) suffers from turbocharger bearing failure and timing chain tensioner issues. The M139 (2019+) has reported cylinder head valve spring failures and oil consumption.

• M133 turbocharger failure due to oil feed line contamination - a service campaign was issued
• M133 timing chain rattling on cold start signals imminent tensioner failure
• M139 broken valve springs causing misfires, rough running and starting problems
• M139 oil consumption requiring more frequent top-ups
• Regular oil changes every 10,000 miles are critical for engine longevity

With proper maintenance, the M133 engine can reach 100,000-150,000 miles. The M139 is too new for full longevity data but has reported cylinder head failures at 20,000-50,000 miles in some cases.

• M133 (2013-2019): 100k-150k miles with regular servicing
• M139 (2019+): cylinder head failures reported at 20k-50k miles; well-maintained units may exceed 100k miles
• Regular oil changes every 10,000 miles (not Mercedes' 15,000-18,000 mile interval) significantly extends life

All CLA 45 AMG models use high-performance engines, but the M133 (2013-2019) has well-documented turbocharger and timing chain issues. The M139 (2019+) has cylinder head and oil consumption concerns.

• 2013-2015 M133: turbocharger failure and timing chain tensioner issues
• 2016-2019 M133: improved but turbo failures still reported
• 2019-2021 M139: cylinder head valve spring failures reported
• 2022+ M139: improved but monitor for oil consumption
• Always check service history for regular oil changes using Mercedes-approved oil

Turbocharger replacement on a CLA 45 AMG M133 engine costs £2,800-£3,800 at a specialist or £4,000-£5,500 at a main dealer. If turbo debris has circulated through the engine, full engine replacement at £5,500-£8,000 is required.

• Specialist turbocharger replacement: £2,800-£3,800 including parts and labour
• Dealer pricing for same work: £4,000-£5,500
• AMG issued a service campaign for turbo failure due to oil feed line contamination
• If turbo debris has contaminated the oil system, full engine replacement is required

Yes. A CLA 45 AMG is worth £15,000-£50,000 depending on generation - a rebuilt engine at £5,500-£11,000 represents roughly 15-30% of the car's value, making replacement economically justifiable for a car in otherwise good condition.

• CLA 45 AMG with good body/interior: replacement engine is cost-effective
• Specialist rebuilt engines fix original design weaknesses and include warranty
• Compare against £7,000-£12,000 main dealer new engine quotes

No. The CLA 45 AMG uses the M133 (first-generation) or M139 (second-generation) engine with significantly higher power output (360-421 hp), while the CLA 35 AMG uses the M260 DE20 LA engine (306 hp). They are not interchangeable.

• CLA 45 AMG (2013-2019): M133, 360-381 hp
• CLA 45 / 45 S AMG (2019+): M139, 387-421 hp - hand-built AMG engine
• CLA 35 AMG (2019+): M260 DE20 LA, 306 hp - different engine family
• Engine codes, mounting points and electronics are not compatible between the two