How much is an overhaul kit?

Send engine model + measured sizes for an exact quote.

Top-end only possible?

Only with even compression and top-end symptoms; blow-by means bottom end.

Break-in after overhaul?

Yes — first 50 h: no full load, then early oil change.

When Does an Excavator Engine Need an Overhaul? 5 Checks Before You Decide

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Short answer: An engine needs an overhaul when measured data — not hours — says so: compression below ~70% of new spec, oil top-ups beyond ~0.5 L per 100 hours, heavy blow-by, oil pressure dropping under load, or metal particles in the oil. One symptom alone is not enough; two or more confirmed by measurement means the rings, bearings or liners are worn past economical repair.

The 5 checks, in order of cost

Check	How	Overhaul territory when
1. Exhaust color	Cold start + warm-up watch	Continuous blue smoke after warm-up (oil burning), not black (fuel) or white (coolant)
2. Oil consumption	Top up over 100 h, same conditions	> ~0.5 L/100 h on a mid-size engine, rising month over month
3. Blow-by (crankcase)	Open oil cap at idle; feel pressure; check breather	Strong steady puff / cap pushed up = rings or liners worn
4. Compression / leak-down	Warm engine, all cylinders, injectors out	Below ~70% of new spec, or cylinders differ by more than ~10%
5. Oil analysis / filter cut	Cut open the oil filter, check for copper/steel glitter	Bearing material in the filter — stop running, avoid a thrown rod

Before you decide: rule out the cheap causes

Low oil pressure — first check the relief valve and oil cooler, not the bearings.
Blue smoke only on cold start — often valve stem seals or turbo seals, a fraction of overhaul cost.
White smoke + coolant loss — head gasket or cracked head, not bottom-end wear.

If it is overhaul: STD or +0.50?

Measure every crank journal and bore first. Within spec → STD kit. Crank ground −0.50 or bores bored +0.50 → matching oversize kit. The machine shop's grind sheet decides the sizes, never the hours on the meter. We supply full overhaul kits, individual bearings, liners, heads and gasket sets for CAT, Komatsu, Isuzu and Cummins engines — search your engine model.

Frequently asked questions

How much does an overhaul kit cost?

Depends on engine family and STD vs oversize. Send the engine model and the measured sizes — we quote the exact kit, not a guess.

Can I overhaul only the top end?

Sometimes: if compression is even but valve seals leak, a top-end job may hold. With blow-by + metal in oil, the bottom end is coming apart anyway.

How long will an overhauled engine last?

With correct sizes, clean assembly and proper break-in oil changes, a quality kit typically matches several thousand more hours of normal duty.

Planning an overhaul?

Send the engine model + measured sizes — we match the exact kit and liners.

Get a kit quote