Plug-in Hybrid Crankcase Ventilation: Valve, Hose, Separator

Plug-in hybrid crankcase ventilation: valve, hoses and separator aren't one part

Scope: 2026 Qin L DM-i, China mainland; PDF pp. 355 and 358; Gates is used only to explain general product categories and does not show that the Qin L uses its designs or products

First separate the part names

The Qin L maintenance schedule lists checks of the PCV valve and the ventilation hoses separately. Gates's official product page lists crankcase ventilation pressure regulators, PCV valves and oil separators as separate product categories, showing that the names that come up in ventilation repairs cannot all be treated as one part. That classification is general background; it does not show that the Qin L has a separately replaceable separator or uses Gates parts. ^{[1] [2]}

Don't let one kind of evidence stand in for another

A hose inspection result should relate to the hose's actual condition, and a valve inspection to the valve; finding one problem is not enough to declare that the other part needs replacing too. The workshop can record the item inspected, the finding and the action separately. The manual gives only maintenance items, not this car's valve flow, pressure or hose replacement specifications, and these values cannot be filled in from general product marketing. ^{[1] [2]}

Symptoms still need matching diagnosis

Ventilation-related complaints must be assessed by professionals using this car's engine information; oil marks or idle changes do not by themselves mean the PCV valve has failed. Do not alter the ventilation path, fit generic hoses or test by removing the oil filler cap and listening. This article's specific focus is which evidence belongs to the valve and which to the connecting hoses; before buying, the exact item must be identified rather than replacing the whole system by default. ^{[1] [2]}

Sources

[Source 1] BYD China official website: 2026 Qin L DM-i Owner's Manual (in Chinese) (public PDF on the official website)
https://www.byd.com/material/domestic-official/user-manual/dynasty/2026%E6%AC%BE%E7%A7%A6L%20DM-i%E7%94%A8%E6%88%B7%E6%89%8B%E5%86%8C20260417.pdf
[Source 2] Gates: PCV Oil Separators and Pressure Regulators
https://www.gates.com/us/en/other-products/engine-hose-air-intake-emissions/emission-control-hose.p.7471-000000-000001.html
Verified: 2026-10-03; page publication date not confirmed.

This article contains information-organising suggestions from the editorial team; it is not a manufacturer repair procedure.