Nissan’s VR30DDTT engine has won a few “Best Engine” awards over the years. It produces great power and has some solid performance potential. But is it reliable enough to deserve the awards its won?
The VR30DDTT suffers from a few common problems, including drive belt issues, carbon build-up, and fuel injector failure. But these problems are mostly minor in nature – making these engines very reliable in our opinion. In this guide we’re going to dig into each of the problems in more depth and discuss overall engine reliability as well.
Nissan VR30DDTT Engine Problems
- Drive belt
- Carbon build-up
- Fuel injectors
1) Drive Belt Issues
The drive belt is also known as an accessory belt or serpentine belt. It’s one of the more common problems on the Nissan VR30DDTT engine. However, these issues are hopefully resolved for the long-term by now. Infiniti did address this failure with a service bulletin, and it doesn’t seem to be a common issue on newer engines. It mostly affects 2016 and 2017 Infiniti Q50 and Q60 models.
We typically avoid discussing these sorts of failures since all new engines are subject to minor design flaws. Fortunately, Nissan and Infiniti were quick to address the VR30DDTT drive belt problems. It’s still worth the mention since serpentine belt failure can cause a plethora of more serious failures.
Drive belts slipping off the pulley is the main issue at hand. Once that occurs you’ll notice power loss, engine lights, etc. It can also cause the engine to overheat causing further damage. Again, 2018+ VR30DDTT models shouldn’t run into drive belt issues but it’s not impossible. If you own a 2016 or 2017 engine and the drive belt has not been addressed then it’s a good thing to look into sooner than later.
Drive Belt Symptoms
- Squealing/noisy belt
- Multiple dash lights
- A/C or Heat Issues
- Power loss
Given this was addressed with a service bulletin Nissan and Infiniti should cover the cost of repairs. A service bulletin isn’t necessarily a recall or extended warranty, though. We would recommend checking to ensure this is taken care of prior to the VR30DDTT running out of warranty. Chances are they’ll still cover the repair outside of warranty, but better safe than sorry.
2) Carbon Build-Up Problems
All engines produce some natural oil blow-by. This oil then makes its way into the intake ports where it can stick to intake valves and form carbon deposits. It’s a non-issue with port injection since fuel is flowing through the intake ports and valves. However, many modern engines like the VR30 twin turbo use direct injection. Fuel enters the cylinder directly, so there isn’t any flowing over the valves.
Over time, this leads to carbon build-up on intake valves and ports. DI is otherwise excellent technology, and we’ll gladly accept the trade-off of better fuel economy, emissions, and performance. Anyways, look for carbon build-up to become problematic on the VR30DDTT around the 80,000 to 120,000 mile ballpark.
- Rough idle
- Stuttering / hesitation
- Power loss
As carbon deposits form they begin restricting air-flow into the cylinders. This can throw off the AFR and cause misfires, rough idle, and stuttering or hesitation while accelerating. Power loss is a major symptom since less air-flow means less power. It’s really hard to detect power loss, though. Carbon build-up gradually gets worse over the course of 50,000+ miles, so it’s not a sudden loss of power.
Walnut blasting is typically the preferable way to clean carbon deposits from intake valves and ports. The process involves a heavy duty shop-vac and walnut media shells. Most of the expense involved is related to labor since the intake manifold must come off to access intake valves.
For the DIY crowd walnut blasting the VR30DDTT engine only costs about $20-30 in walnut media shells. At a repair shop it can be a $300-600 job due to the labor. Again, it’s a fairly minor problem in the grand scheme and some engines will probably go their whole lives without walnut blasting.
3) Fuel Injector Failures
Fuel injector failures are another one of the most common problems on the Nissan VR30DDT engine. There is also a service bulletin addressing fuel injector failures. Some attribute this to mods, tunes, and running E85 fuel blends. However, there are also numerous failures occurring on completely stock VR30 engines.
It seems failures are happening due to metallic debris coming from the OEM fuel rail. This indicates the fuel rail could still cause aftermarket injectors to suffering similar problems. As such, the underlying fuel rail issues should be addressed.
Nissan and Infiniti did release a new OEM fuel rail to remedy these problems. Hopefully this suffices as a long-term solution. Given Nissan is aware of the problems we assume they’re also fixing this on new VR30 engines from the factory. In other words, this appears to just be another minor kink that all new engines are prone to.
This article goes into a bit more depth and may be a helpful resource for those wanting to learn more about VR30DDTT injector failures.
Bad Injector Symptoms
- Fault codes P0301, P0302, P0303, P0304, P0305, P0306
- Check engine light
- Rough idle
- Poor performance
Fuel Injector Fix
We couldn’t track down the full service bulletin, but it’s out there somewhere. Nissan and Infiniti are aware of these problems with the VR30DDTT fuel injectors. As such, they’ll likely help with and cover any issues. If you’re stuck paying out of pocket ensure you track down the newest OEM fuel rails.
Additionally, aftermarket or new OEM injectors won’t always solve the root cause. If the fuel rail still has debris it can quickly take out any replacement injectors.
Nissan VR30DDTT Reliability
Is the Nissan VR30DDTT 3.0 V6 engine reliable? Yes, we believe this is a reliable engine overall. As these engines continue to age we suspect more problems will arise with carbon build-up and your typical maintenance related things like water pumps, spark plugs, and so on. However, with proper maintenance and care we don’t see any flaws with this engine that would lead to premature engine failure or any significantly expensive repairs.
The Nissan & Infiniti VR30 twin turbo engine is an exciting and promising engine. It offers a very respectable 300-400hp from the factory, and has even more potential with a few bolt-on upgrades. These engines offer a good all around balance of performance, efficiency, and reliability. However, no engine is perfect and that applies to the VR30 V6 engine too.
A few common VR30DDTT problems include drive belts and fuel injectors. These can likely be chalked up to early design kinks that simply needed some time to be worked out. Nissan/Infiniti were quick to address the problems and come up with solutions, so that’s promising. Otherwise, carbon build-up is simply a downside to what we believe is an excellent technology.
Ultimately, these have proven to be reliable engines with very few common failure points.