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J-series

J30 Engine in Phoenix, Arizona

The 3.0-litre J-series V6 that sat below the J35 in displacement and powered Honda's six-cylinder Accords and Acuras through the late 1990s and 2000s.

Family
J30 (J-series)
Displacement
3.0 L
Configuration
V6, 60-degree
Valvetrain
SOHC, 24 valves
Produced
1996–2007

Bore and stroke are omitted for this family: the code covers variants with different figures, and a single pair of numbers would be wrong for some of them.

The J30 is Honda's 3.0-litre V6, a member of the J-series family that also includes the larger J32 and J35. It was fitted to the Honda Accord V6 from 1998 to 2007 and to a range of Acura models during the same period. The engine uses a 60-degree V6 layout with a single overhead camshaft per bank and 24 valves.

Two principal variants matter for replacement buyers: the J30A4, used in the 1998–2002 Accord V6, and the J30A5, used in the 2003–2007 Accord V6. The two differ in intake manifold design and emissions calibration, which means they are not interchangeable without addressing the engine management.

Because the J30 and J35 share the same J-series architecture, they are sometimes discussed as though they are interchangeable. They are not. The displacement difference of 0.5 litres reflects different bore and stroke dimensions, and the two have different part numbers for key components. A replacement should match the exact variant code of the original.

The J30 is not a smaller J35

Because the J30 and J35 share J-series architecture, they are sometimes treated as though one can substitute for the other. They cannot. The 0.5-litre displacement gap reflects different bore and stroke dimensions, and the two have different part numbers for key components including the timing belt, water pump and intake manifold.

A replacement should match the exact variant code of the original. Supplying the year, trim and VIN removes the ambiguity that the family code on its own leaves.

J30A4 versus J30A5

The J30A4, fitted to the 1998 to 2002 Accord V6, and the J30A5, fitted to the 2003 to 2007 Accord V6, differ in intake manifold design and emissions calibration. They are not interchangeable without addressing the engine management.

Because both are timing belt driven, the belt, tensioner and water pump should be treated as part of the installation cost on any used unit regardless of which variant it is.

Vehicles built with a J30

A narrower range than the J35, concentrated on the Honda Accord V6 and a selection of Acura models during the same production window.

Factory applications for J30 variants, by vehicle, model years, trim and market
VehicleYearsTrim / bodyEngine codeMarket
Honda Accord1998–2002V6J30A4USDM
Honda Accord2003–2007V6J30A5USDM

J30 variants

Two principal US-market codes, split across two generations of the Accord V6. The intake manifold and emissions calibration are what separate them.

J30A4USDM
Earlier Accord V6, 1998–2002. Distinct intake manifold and calibration.
J30A5USDM
Later Accord V6, 2003–2007. Revised intake and emissions calibration over the A4.

Identifying a J30

  • The J-series code is stamped on the block; the suffix identifies the variant and generation. J30A4 and J30A5 are the common US-market codes.
  • Distinguishing a J30 from a J35 visually is difficult without reading the stamp, because the external dimensions are similar. The stamp is the reliable method.
  • The J30A4 (1998–2002) and J30A5 (2003–2007) differ in intake manifold shape, which is visible with the engine bay open.

A seller describing an engine as a particular variant is making a checkable claim. Asking for a photograph of the stamp on the actual unit is not a sign of distrust; it is the normal way this gets confirmed. The engine code guide shows where each family is stamped if you want to read the one in your own car first.

What varies between J30 units

These are the differences that decide whether two engines with the same family code are substitutes in a particular car.

  • The J30 and J35 share J-series architecture but are different displacements with different bore and stroke. They are not drop-in substitutes for one another.
  • J30A4 and J30A5 differ in intake and emissions calibration; supply the year and trim to confirm the correct variant.
  • Like other J-series engines, the J30 is timing belt driven. Treat the belt, tensioner and water pump as part of the installation on any used unit.

Nothing on this page confirms that a specific J30 will work in your vehicle. That takes the year, model and trim at one end and a specific unit at the other, and it happens before a price is given rather than after. What goes into that check is set out here.

Ask about a J30 for your vehicle

The code is pre-filled. Add the year, model and trim, and the variant question gets settled on our side before anything is confirmed.

Step 1 of 3 · Vehicle33%

Step 1 of 3: Vehicle

Which vehicle is the engine for?

Year, make and model get us most of the way. Trim matters more than people expect. A 2008 Civic is a different engine depending on whether it is an Si.

LX, EX, Si, Type-S, V6. Whatever is on the badge.

Know your engine code? Add it here.

If you do not, leave these blank. That is genuinely fine. Working out which engine a vehicle takes is the part we do. Here is where the code is stamped if you want to look.

The single most useful thing you can give us. 17 characters.

We do not confirm that an engine fits your vehicle until it has been checked against it.

Common questions

Is the J30 the same as the J35?

No. They share the J-series architecture but differ in displacement, bore and stroke, and part numbers for key components. A J30 is not a drop-in substitute for a J35 and vice versa. Supply the exact variant code when requesting availability.

Which Honda models used the J30?

The J30 was fitted to the Honda Accord V6 from 1998 to 2007, split between the J30A4 (1998–2002) and the J30A5 (2003–2007). It also appeared in certain Acura models during the same period.

Find the right engine for your vehicle

Tell us the year, model and trim. We identify the engine your vehicle takes and come back with current availability and pricing.

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