Engine oil
Coolant in engine oil
Running with coolant in oil is dangerous: lubrication deteriorates and bearings/other parts can quickly suffer. The cause is not always the head gasket; check head, liners, block and engine oil cooler.
Head gasket
Damage may follow overheating, aging, corrosion, incorrect assembly or head/block distortion. Do not replace it automatically without checking other paths.
Cracked head
A crack may connect a coolant passage to an oil passage or cylinder. Check pressure testing, flatness, cracks, seats/chambers and overheating history.
Cylinder liners
With wet liners, sealing rings, cavitation damage, cracks or corrosion may let coolant into the crankcase. It may enter the sump directly without obvious head-gasket symptoms.
Engine oil cooler
Many engines have a coolant-fed oil cooler on or near the block. Mixing can result from core damage, cracks, corrosion, gaskets or incorrect repair assembly. A separate cooler check may be sensible before removing the head.
Signs to look for
Rising oil level, cloudy oil/emulsion, coolant loss, changing oil pressure, overheating and water/coolant collecting in the sump after standing. Hot running oil does not always immediately look like “mayonnaise”.
Related problems
Further service support
Problem still there?
If these checks have not identified the cause or the fault returns, contact TSV Servis. The more initial information you provide, the sooner we can identify the next diagnostic direction.
What to send us
Engine model, S/N, coolant-loss rate, oil condition, overheating history, cooling pressure-test results and checks of oil cooler, head and liners.
Include the make and model, S/N or a nameplate photo, engine model if known, operating hours, exact code or display photo and when the fault occurs.
Also tell us what you have already checked or replaced and the results. Include a photo or short video of the symptom where useful.
+420 722 307 850 · tsvcz@seznam.cz