My brother and I recently completed a successful LLT to LFX engine swap for my 2009 SIDI VE SV6 ute and figured it would be beneficial to share the process for anyone else who is thinking of doing the same. The whole swap was completed for just the price of the LFX + cats, with no tuning or reprogramming required. All up the swap took my brother and I about 24 hours spread over 4 afternoons, but you could probably smash it out in 1 weekend.
So why would you choose to do this in the first place? I’m sure anyone with a shagged LLT engine could tell you just how hard to find and expensive a fresh LLT is, costing about 25-50% more than a similar LFX. The LFX is much more common, being in all SV6s since the VE Series II, so you’re more likely to find a newer, low km engine for cheaper. The LFX is essentially a new and improved version of the LLT, with integrated exhaust ports, a lightweight redesigned intake manifold, Fuel Flex (E85) capability and a slightly higher compression ratio. But because of these differences it isn’t a direct swap with the LLT. It runs a different ECU, different fuel pump and injectors and slightly different wiring harness. Because of this most people will tell you it’s not worth doing because it will be too hard or expensive once you find the right parts and software to make everything work. But my brother and I worked out a much simpler process which is comparable to a direct drop in swap.
The only things I had to buy to complete the swap was an LFX engine (which came out of a 2016 VF SV6) and the catalytic converters/header pipes to match. All other parts and electronics came directly off my original LLT engine. I also had access to a car hoist, transmission jack and a forklift to remove and install the engine.
To start with you will have to remove the bonnet, and removing your front bumper and headlights will also allow better access to the engine bay, but isn’t 100% necessary. Next, drain your coolant, oil, power steering fluid and clutch fluid. Then you need to disconnect everything connecting the engine to the car. We removed the engine by first dropping the transmission with the jack, then lifting the engine out separately with the forklift. We didn’t remove the radiator to save having to recharge the AC later, but the whole front end can be removed to allow the engine and transmission to come out through the front if needed.
Once the engine is out, remove the wiring harness from both engines, making sure to take note of where it all plugs in. Next, install the LLT wiring harness on the LFX. This is fairly straightforward as the plugs are all identical between the two motors except for a few differences. The water temp sensor on the passenger side is further back and down on the LFX, but plugs in fine. There is also an extra sensor on top of the intake manifold which is not present on the LLT, so we just left this unplugged.
Then you will have to swap the sump from the LLT as the oil level sensor is in a different position and has a different plug. This can be tricky because the bolts on the front of the sump are blocked by the harmonic balancer, so this will need to be removed first to give you clearance. You will likely need to buy a tool for this. Once the sump is swapped you will also have to swap the engine mounts because the LFX ones bolt into the sump while the LLT ones don’t.
Other parts you may have to swap over depending on what came with your LFX engine are the alternator, starter motor, clutch, power steering pump, vacuum pump, and AC compressor. The LFX I had didn’t come with any of these, but if yours does they should be fine as long as they are in the same position and the plugs are the same. Otherwise just swap them all over from your LLT.
The LFX from the VF doesn’t have a power steering pump because the VF has electronic steering (maybe the VE II as well I’m not sure), so that will need to be swapped from your LLT. You will of course also have to swap the power steering pump mount.
The mount for the AC compressor on the LFX is also slightly different, so it will need to be swapped as well or the compressor will sit too close to the power steering pump for the drive belt to pass.
Lastly is the fuel system, including the fuel pump and injector assembly. The LFX is Fuel Flex capable, meaning it can run on E85, while the LLT is not. This means the injectors on the LFX are bigger. I’ve heard it is possible to run the engine without swapping these but the car will need to be tuned to accomodate. We made the mistake of not swapping the injectors initially and the car ran way too rich, backfiring heaps and throwing engine codes. It will not run properly without either tuning the car or swapping the pump and injectors.
Swapping the fuel pump is straightforward, but the injectors can be a bit more of a hassle. The injectors on the LLT aren’t designed to be removed with the heads on. They just barely don’t have enough clearance. So to get them out you will either have to remove the heads first, which is a big job, or do like I did and use a die grinder to shave a few mm off the back of the water outlet pipe. Then you should be able to wriggle the injectors free. The LFX injectors come out much easier but will still take some wriggling.
Now you’re ready to install the LLT injectors. Make sure to give them a good clean or even take this opportunity to replace them if necessary. I found it much easier to install the injectors and wiring first, then dab a small bit of silicone grease on the top seals to help the rails pop on afterward. Then just connect everything up and you’re good to go.
Once you’ve done all of this it’s a simple matter of reinstalling the engine the same way you took it out. We chose not to install the new cats until after the engine was back in to give us more room, but it can be hard to access the bolts once it’s in, so do whatever you find easiest there.
Once the engine and transmission is in everything will connect straight back up as it was before. The cats will bolt straight up to your original catback exhaust as well.
Once everything is reinstalled, make sure to replace any fluids you drained and bleed your clutch and power steering if needed.
Finally, start the car. It should almost start straight up and shouldn’t throw any engine codes. When I started mine up first it did throw an engine code, but a quick look with the scan tube showed a faulty cam position sensor from when the engine tipped over during travel, so we swapped that out and had no more engine codes.
I’ve since driven several hundred km with no issues. Power feels good, fuel economy is good, runs very smooth. I’d definitely recommend doing this swap if your LLT engine is shagged and you have the means of removing an engine in the first place.
