Sailing Zephyr IVvideo
Volvo Penta 2003 Smoking? Try This Simple Tune Up!
November 16, 2025 · 5 min · 10K views
What this video covers
A Volvo Penta 2003 diesel on the Westerly Oceanquest 35 *Zephyr IV* develops black exhaust smoke at high throttle and a slow oil leak from the rocker box gasket.0:14 Dave traces the smoke to a clogged air filter — a perforated metal screen with no recorded cleaning in over 30 years of the boat's log.0:56 He removes it with a 9 mm spanner, cleans it first by tapping with a wooden block and vacuuming, then soaks it in hot concentrated washing-up liquid rather than the handbook's recommended diesel wash, rinses it, and sun-dries it before refitting.1:24 The oil leak traces to the rocker box gasket, replaced with a thin nitrile rubber unit; the old cork-style gasket is no longer fitted.3:08 Tappet adjustment is also covered, though Dave defers the detailed rocker box removal and tappet procedure to a separate video by Rob of Sailing With Us, citing restricted access above Zephyr IV's engine.3:38 After all three jobs — air filter clean, gasket replacement, and tappet adjustment — the exhaust clears, the oil leak stops, and the engine runs quieter with less vibration.4:43 A blocked air filter on a long-neglected diesel can mimic a rich-mixture condition and cause black smoke before any fuel system fault is suspected.
Boats in this video
More from Sailing Zephyr IV
From Sailing Zephyr IV — see the channel’s boat, crew, and every analyzed video.
The Sailing Directory Newsletter
One email with the fleet's best finds — the moments, boats, and stories worth your watch time. Enter your own address to get your own copy.