3804618 Unit Injector Core | Genuine Volvo Penta Part

🔧 Product Description

Core deposit for a unit injector, in the Fuel System group. It is the refundable charge raised against the old unit injector when the exchange unit is bought, and it comes back once the worn unit injector is returned. The line itself is an accounting entry rather than a part, so nothing ships against it on its own. Under Volvo Penta's core numbering it pairs with part 3801618, which is the number to quote for the component itself and which our own range lists as Unit Injector Exch. The other unit injector cores running through this block are 3804617 and 3804652, and nothing published against them separates one from another, so order the number that matches the unit injector actually coming off. Both wordings appear in this block - injector cores 3804624, 3804627 and 3804661 alongside unit injector cores 3804617, 3804618 and 3804652 - and the core-side naming is not always precise, so work from the paired number rather than the wording.

⚙️ Key Features

• Core deposit line, not a unit injector you can fit
• Pairs with part 3801618, listed as Unit Injector Exch
• Refunded when the old unit injector is returned
• Not separable from unit injector cores 3804617 and 3804652, so order by part number
• Fuel System group

🔌 Function

As a line item it carries the refundable core charge on the exchange; the unit injector itself meters and pressurises the fuel for one cylinder in a single camshaft-driven unit, spraying it into the combustion chamber at the moment of injection.

⚠️ Common Signs of Failure

• This is a deposit line and has nothing to fail in itself; the signs below are what normally condemns the unit injector being exchanged
• Rough idle with a knock from one cylinder, worst when the engine is cold
• Hard starting, smoke at the exhaust and a smell of unburnt diesel around the engine
• Fuel consumption up, and the oil level rising as fuel dilutes the sump
• On removal, a nozzle that dribbles instead of spraying cleanly, coked or eroded spray holes and a sooty ring at the seat

🛠️ Service Notes

• The charge is refunded when the worn unit injector is returned, so keep the old unit and arrange the return collection when the order is placed rather than scrapping it
• Ordering this number on its own supplies no part - it goes on the order beside the exchange unit, part number 3801618
• Renew the copper seat washer and the O-rings on refitting, and prove the fuel is clean before the exchange unit goes in, since dirt or water will take the next one out as well.

📦 Condition

• Refundable core deposit - not a physical part