How much does a BMW 325e engine replacement cost in the UK?

A reconditioned 325e (M20B27) engine typically costs £1,500–£2,800 supply only. Fitting adds £650–£1,300 depending on location and workshop rates. Used engines start from £300–£800 supply only. A full rebuild with timing belt, water pump and gaskets costs around £1,500–£2,800.

Is the BMW 325e engine reliable?

Yes - the M20B27 is widely regarded as one of BMW's most durable engines. Many owners report 200,000+ miles with proper maintenance. The engine was designed for efficiency and low-rev torque, with a robust cast iron block and simple SOHC design. However, the timing belt must be replaced every 60,000 miles or 4 years - failure is catastrophic.

What are the common problems with the BMW 325e?

The main issues are: (1) Timing belt failure if not replaced on schedule - this is catastrophic and the most common cause of engine death, (2) Vacuum leaks causing idle issues - rubber components age and crack, (3) Ageing cooling system components - hoses, radiator, water pump and thermostat, and (4) Rust - the real enemy of E30s, not the engine.

Is it worth replacing a BMW 325e engine, or should I scrap the car?

Depends on vehicle value and condition. Against a well-kept £4,000–£10,000 325e (E30 values have risen significantly), a £2,200 recon is 20–55% of the car's value - worth it for a clean example. For a car with significant rust, evaluate restoration costs before committing to an engine replacement.

How do I find my BMW 325e engine code?

The 325e uses the M20B27 engine. Early cars (1984–1987) are the standard "Eta" with 121 hp and a 4,800 rpm redline. The 1988 model year is the "Super Eta" with 127 hp, a 5,500 rpm redline, and 325i cylinder head components. The engine code is stamped on the cylinder block. Tell us your registration date and we'll confirm it for free.

How often should the timing belt be replaced on the 325e?

The timing belt must be replaced every 60,000 miles or 4 years - whichever comes first. The M20B27 is an interference engine - if the belt breaks, pistons will hit valves. This results in bent valves at minimum, all the way to catastrophic damage requiring a full engine replacement. If you don't know when the belt was last changed, assume it needs doing immediately.

BMW 3 Series 325e1984–19881 Engine Generation (2 Variants)

BMW 325e Engine Replacement — Compare Prices & Get Quotes

Name: BMW 325e UK Engine Enquiry Data 2025
Creator: BMWEngines.uk

Get quotes today from trusted UK BMW 325e specialists. The 2.7-litre M20 "Eta" six-cylinder is one of BMW's most durable and fuel-efficient classic engines - compare reconditioned, rebuilt and used engines with supply & fit available nationwide.

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BMW 325e Engines - from £300 to £3,500Engine code: M20B27 (Eta / Super Eta)

BMW 325e Engines - from £300 to £3,500· Engine code: M20B27 (Eta / Super Eta)

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BMW 325e - Which Engine Does Your Car Actually Have?

Four generations. Four eras. One guide to reliability, costs and what really matters.

Era Note

2.7L SOHC six - low-rev torque monster, 121 hp. Timing belt is the single critical maintenance item

GenerationYearsEngine CodeReliabilityRecon CostEra Note

E30

1984–1987M20B27 (Eta)★★★★☆ [NEWLY ASSIGNED - see Data Note]£1,500–£3,500 [PLACEHOLDER]2.7L SOHC six - low-rev torque monster, 121 hp. Timing belt is the single critical maintenance item

E30

1988M20B27 (Super Eta)★★★★☆ [NEWLY ASSIGNED - see Data Note]£1,500–£3,500 [PLACEHOLDER]Final-year "Super Eta" - 127 hp, 5500 rpm redline, 325i head & Motronic 1.1

Why use this era map?

Every cost guide, reliability rating and engine code on this page is aligned to the data above. This keeps everything consistent and trustworthy.

Real UK Cost Data

Verified Reliability

Expert Insights

Updated for 2025

BMW 325e Engine Replacement Costs

Supply Only£1,500–£2,800

Fitted (Indie)£2,500–£4,000

Warranty12–24 months

Best ForMost owners - best cost/warranty balance

Engine TypeSupply OnlyFitted (Indie)WarrantyBest For

Used Engine£300–£800£800–£1,5001–6 monthsBudget priority; donor for rebuild

Reconditioned Engine£1,500–£2,800£2,500–£4,00012–24 monthsMost owners - best cost/warranty balance

Rebuilt Engine£2,200–£3,500£3,500–£5,00012–24 monthsLong-term ownership; 3+ year horizon

Main Dealer NewN/AN/AN/ANo longer manufactured

Labour estimate: Fitting a 325e engine typically takes 8–12 hours at £65–£95/hr (independent). A timing belt and water pump replacement - the single most critical maintenance item - typically costs £300–£600 parts and labour.

→ Compare 325e engine prices from UK specialists

Common Problems With BMW 320d Engines

1. Timing Belt Failure (Catastrophic)

Symptoms: No symptoms before failure - belt snaps without warning, engine stops, no restart

Typical mileage: 60,000 miles or 4 years - whichever comes first

Repair cost: £300–£600 (preventative belt, tensioner and water pump replacement)

Replacement cost: £2,500–£5,000 (if belt snaps - full engine rebuild or replacement)

🔴 Immediate - if you don't know when the belt was last changed, replace it NOW

Our recommendation:

This is the single most critical maintenance item on the M20 engine. The M20B27 (and ALL M20 engines) are interference engines - if the timing belt breaks, pistons will hit valves. Depending on engine speed, this results in bent valves at minimum, all the way to catastrophic damage requiring a full engine replacement. The belt should be replaced every 60,000 miles or 4 years. If you're buying a 325e with no documented timing belt history, assume it needs doing immediately and use it as a bargaining point. Replace the water pump and tensioner at the same time.

Read the full timing belt failure guide

1. Timing Belt Failure (Catastrophic)

Symptoms: No symptoms before failure - belt snaps without warning, engine stops, no restart

Typical mileage: 60,000 miles or 4 years - whichever comes first

Repair cost: £300–£600 (preventative belt, tensioner and water pump replacement)

Replacement cost: £2,500–£5,000 (if belt snaps - full engine rebuild or replacement)

🔴 Immediate - if you don't know when the belt was last changed, replace it NOW

Our recommendation:

Read the full timing belt failure guide

2. Vacuum Leaks (Idle Issues)

Symptoms: Erratic idle, hunting idle, stalling, rough running, poor fuel economy

Typical mileage: Any mileage - rubber components age and crack

Repair cost: £100–£300 (intake boot, vacuum hoses, valve cover breather hose)

Replacement cost: N/A - repair only

🟡 Monitor - book inspection if idle issues develop

Our recommendation:

The M20 engine is very sensitive to vacuum leaks, which cause idle issues. The intake boot and the hose from the valve cover to the intake are prime culprits. Other common failure points include the idle control valve (ICV), ageing main and fuel pump relays, cracked intake boots, and brittle coolant hoses. If you experience rough idle or stalling, start by checking for vacuum leaks - this is often a simple and inexpensive fix.

Read the full vacuum leak guide → /failures/vacuum-leaks/ [NEW FAILURE PAGE NEEDED]

3. Cooling System Ageing

Symptoms: Coolant loss, overheating, temperature gauge fluctuating, steam from engine bay

Typical mileage: 60,000–100,000 miles - rubber and plastic components age

Repair cost: £200–£600 (radiator, hoses, thermostat, water pump)

Replacement cost: N/A - repair only (does not progress to engine replacement if addressed)

🟠 Check - book inspection if you notice coolant loss or overheating

Our recommendation:

The cooling system on the 325e is ageing - every piece of rubber either has been or will need replacing. Common failures include brittle coolant hoses, the radiator end tanks cracking, and the thermostat sticking. The water pump should be replaced with the timing belt as a matter of course. If you notice the temperature gauge rising, shut the engine down immediately - overheating an M20 can cause head gasket failure or worse.

Read the full cooling system guide

Weighing Your Options?

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20+ vetted BMW specialists, every 325e engine era covered, with a 12-month warranty as standard.

See 325e Engine Options

325e - Repair, Buy, or Replace?

Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.

325e - Repair, Buy, or Replace?

Every 320d has a story. Make the right call with clear data, real-world costs, and honest guidance from UK specialists.

Can It Be Repaired?

ProblemRepairable?Typical CostWhen It Makes SenseTiming belt (preventative)✅ Yes£300–£600Essential maintenance - do it on scheduleTiming belt snapped❌ Usually NoEngine replacementInterference engine - piston-valve contact requires full rebuild or replacementVacuum leaks✅ Yes£100–£300Simple DIY or specialist fixCooling system components✅ Yes£200–£600Preventative replacement is recommendedHead gasket failure✅ Yes£600–£1,200Viable on well-maintained examples

Buying This 325e? Check These First

Buy If

Documented timing belt replacement within the last 60,000 miles or 4 years - this is non-negotiable
Full service history with regular oil changes
No evidence of overheating or coolant loss
Good body and chassis condition - rust is the real enemy on E30s

Avoid If

No timing belt history - this is a ticking time bomb
Overheating history or cooling system issues - the M20 is unforgiving of overheating
Erratic idle that hasn't been diagnosed - likely vacuum leaks but could be more
Significant rust - E30s are appreciating classics, but rust repair is expensive

Closing Verdict

The 325e's M20B27 "Eta" engine is one of BMW's most durable and characterful powerplants - a 2.7-litre straight-six that prioritises low-rev torque and fuel economy over peak horsepower. The "e" stands for efficiency, and the engine delivers: 170 lb-ft of torque at just 3,250 rpm, with an incredibly flat powerband. The key to a long life is simple: change the timing belt on schedule. At 60,000 miles or 4 years, this is non-negotiable. With that done, the M20B27 is capable of 200,000+ miles. Buy on documented history, not on optimism.

Don't guess.Get the right engine at the right price.

→ Compare 325e engine prices before you buy

Don't Guess. Compare.

Get real quotes from vetted UK specialists and make the right call for your 320d.

→ Compare 325e engine prices before you buy

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Buying Checklist

Before you buy a used BMW 325e (or before you commit to an engine replacement), check these:

Timing Belt History

Has it been changed within the last 60,000 miles or 4 years? This is critical

Cold Start

Listen for rattling, ticking, or rough idle on start-up

Idle Quality

Does the engine idle smoothly, or does it hunt or stall? (Vacuum leaks)

Cooling System

Check for coolant leaks; ask about water pump, radiator, thermostat history

Service History

Including the M20B27 engine and confirmed oil change intervals

Oil Leaks

Look for oil residue around the valve cover and timing case

Rust

Check rocker panels, battery box (in trunk), jack storage area, passenger floor boards, bottom of doors

MOT History

Check for emissions-related failures

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.

Buy smart. Drive with confidence.

A few checks today can save thousands tomorrow. Use this checklist to avoid the most common 320d pitfalls.

BMW 320d Engine Codes

This table's rows match Section 1B's Era Map exactly.

M20B27 (Eta)

Years1984–1987

Power121 hp (90 kW) / 170 lb-ft (230 Nm)

2025 Enquiries- (pattern data)

Avg. Recon Cost£1,500–£3,500 [PLACEHOLDER]

Engine CodeYearsPower2025 EnquiriesAvg. Recon Cost

M20B27 (Eta)1984–1987121 hp (90 kW) / 170 lb-ft (230 Nm)- (pattern data)£1,500–£3,500 [PLACEHOLDER]

M20B27 (Super Eta)1988127 hp (95 kW) / 170 lb-ft (230 Nm)- (pattern data)£1,500–£3,500 [PLACEHOLDER]

Technical Specs

M20B27 Eta

Displacement2,693 cc (2.7L)

Cylinders6-cylinder inline

Bore84.0 mm

Stroke81.0 mm

Cylinder BlockCast iron

Cylinder HeadAluminium

ValvetrainSOHC, 2 valves per cylinder (12 valves total), belt-driven

Compression Ratio9.0:1

Fuel SystemBosch Motronic 1.0 fuel injection with DME

AspirationNaturally aspirated

Power (Eta)121 hp (90 kW) @ 4,250 rpm

Power (Super Eta)127 hp (95 kW) @ 4,800 rpm

Torque (Eta)170 lb-ft (230 Nm) @ 3,250 rpm

Torque (Super Eta)170 lb-ft (230 Nm) @ 3,250 rpm

Redline (Eta)4,800 rpm

Redline (Super Eta)5,500 rpm

0-60 mph8.4 seconds (manual)

Fuel economy22–28 mpg (urban) / 30–34 mpg (motorway)

→ Compare 325e engine prices for your BMW

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Market Intelligence

Most Common Failure

Timing belt neglect

failure to replace at 60,000-mile/4-year intervals leads to catastrophic engine damage【PATTERN DATA】

Average Enquiry Mileage

80,000

–150,000 miles【PATTERN DATA】

Average Replacement Cost

£2,200

reconditioned, supply only【PLACEHOLDER】

Most Requested Engine Code

M20B27【PATTERN DATA】

Peak Enquiry Season

Spring / Summer

classic BMW owners prepare for driving season【PATTERN DATA】

Regional Demand

South East20%

London18%

South West (12%)【PATTERN DATA】

Regional Demand Breakdown

20%South East

18%London

BMW 320d - Frequently Asked Questions

All prices are indicative UK market ranges based on historical quote data from our network of engine specialists. Actual costs vary by variant, engine code, damage severity and workshop location. Use our free comparison tool to get tailored quotes. Every engine supplied through EnginesMarket carries a minimum 12-month unlimited-mileage warranty - always confirm terms with your chosen supplier.

Why UK BMW 325e Owners Trust BMWEngines.uk

Trusted 325e Engine Suppliers
every garage and engine rebuilder in our network is vetted, rated and reviewed by real 325e owners, across both Eta and Super Eta variants of the M20B27 engine, as part of the Engine Finders network.
Compare 325e Engine Replacement Companies
see prices, warranty terms and supply & fit options side-by-side before you commit.
UK Engine Replacement Services for 325e
supply-only or full supply & fit available nationwide, covering every 325e from 1984 to 1988.

Find the best BMW 325e engine replacement UK drivers rely on. Compare prices from trusted specialists on EnginesMarket today and get back on the road with confidence.

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20+ vetted experts

12-Month Warranty

As standard

Nationwide Delivery

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