“Should I Buy This Machine?” Calculator (A High-Hour Excavator Risk Scoring System)

Purpose:Remove emotion, optimism, and seller bullshit from the buying decision.

This calculator does not tell you if a machine is “good” or “bad.”It tells you how dangerous it is to own — and whether the price justifies that danger.

How the Calculator Works (Big Picture)

The machine is scored across 6 critical systems that actually kill excavators:

1. Hydraulic Heat & Efficiency

2. Oil Condition & Contamination

3. Pumps, Motors & Case Drain

4. Cooling System Headroom

5. Engine Risk (Downstream Damage)

6. Seller Transparency & History

Each category is scored from 0 to 5.

• 0–1 = Low Risk

• 2–3 = Manageable Risk

• 4–5 = High / Walk-Away Risk

At the end, you get:

• A Total Risk Score

• A Buy / Buy With Conditions / Walk Away result

• A pricing reality check

SECTION 1: HYDRAULIC HEAT & EFFICIENCY (0–5 POINTS)

Heat is the single strongest predictor of failure.

Score This Section:

0 points

• Oil temp stable under load

• No unexplained overheating

• No history of chronic heat issues

1 point

• Oil runs warm but controlled

• Heat only under extreme conditions

2 points

• Oil temp climbs during normal work

• Operator reports “it gets hot sometimes”

3 points

• Regular overheating complaints

• Cooling system repeatedly cleaned or upgraded

4 points

• Oil runs hot even after repairs

• Cooling system “chased” repeatedly

5 points

• Overheating unresolved

• Seller vague or defensive about heat

👉 If this scores 4–5, everything else matters less.

SECTION 2: HYDRAULIC OIL CONDITION (0–5 POINTS)

Oil remembers abuse longer than sellers do.

Score This Section:

0 points

• Oil clear, correct viscosity

• No burnt smell

• Regular documented oil changes

1 point

• Slight darkening, no smell

• Oil change history believable

2 points

• Dark oil, borderline smell

• “Recently serviced” with no proof

3 points

• Burnt smell

• Visible oxidation

• Sludge or varnish signs

4 points

• Oil thick when cold, thin when hot

• Evidence of overheating cycles

5 points

• Oil clearly cooked

• Seller claims “oil doesn’t matter”

👉 Burnt oil = heat history you cannot undo.

SECTION 3: PUMPS, MOTORS & CASE DRAIN (0–5 POINTS)

Pressure tests lie. Case drain doesn’t.

Score This Section:

0 points

• Case drain tested

• All components within spec

1 point

• Minor elevated case drain on one component

2 points

• Elevated case drain on swing or one travel motor

3 points

• Elevated case drain on pump OR multiple motors

4 points

• Multiple high readings

• Components “still work though”

5 points

• No case drain testing allowed

• Seller dismisses its importance

👉 Refusing testing = hiding wear.

SECTION 4: COOLING SYSTEM HEADROOM (0–5 POINTS)

Cooling systems don’t fail first — they fail last.

Score This Section:

0 points

• Radiator + oil cooler clean internally and externally

• Fan clutch working

• Thermostat verified

1 point

• Minor airflow restriction

• Easy maintenance items outstanding

2 points

• Oil cooler marginal

• Fan runs constantly

3 points

• Repeated cleaning required

• Cooling “just keeps up”

4 points

• Cooling upgrades attempted

• Still runs hot

5 points

• Cooling system blamed for years

• No improvement after work

👉 If cooling has been “chased,” the problem is upstream.

SECTION 5: ENGINE RISK (0–5 POINTS)

Engines are victims, not instigators.

Score This Section:

0 points

• Engine temps stable

• No rebuild history

• No coolant pressurisation

1 point

• Minor leaks, normal wear

2 points

• Past overheating events

• No internal damage yet

3 points

• Head gasket history

• Cooling-related repairs

4 points

• Recently rebuilt engine

• Hydraulics untouched

5 points

• Multiple engine failures

• Seller says “these engines are rubbish”

👉 A new engine can be a red flag, not a bonus.

SECTION 6: SELLER TRANSPARENCY & HISTORY (0–5 POINTS)

Machines don’t lie — people do.

Score This Section:

0 points

• Honest disclosures

• Allows full testing

• Service records available

1 point

• Minor gaps, reasonable explanations

2 points

• Vague answers

• Selective testing allowed

3 points

• Defensive when questioned

• Blames operators or brand

4 points

• Contradictory stories

• Pushes urgency

5 points

• Refuses testing

• “Take it or leave it”

👉 Bad sellers sell bad machines.

TOTAL SCORE & DECISION MATRIX

Add All Sections (Max = 30)

0–8 points → BUY

• Stable wear

• Predictable risk

• Good long-term candidate

9–15 points → BUY WITH CONDITIONS

• Price must reflect repairs

• Budget for components

• Heat must be controlled first

16–22 points → HIGH RISK

• Only buy if deeply discounted

• Expect downtime

• Parts availability critical

23–30 points → WALK AWAY

• Systemic wear

• Heat damage embedded

• Will consume money silently

THE PRICE REALITY CHECK

After scoring, ask one final question:

Does the discount cover the risk — plus the stress?

If the answer is no, the calculator has already done its job.