Sunday, February 4, 2018

RB26DETT Maintenance - Beginners Tips

If you are an early reader of this blog you’ll know that I started my ownership journey with very little mechanical knowledge. That, combined with my limited experience with performance driving, has provided endless source of laughter for Dino and Aki. So, beside being busy looking for better friends, I have also enjoyed researching and learning as much as possible about the technical side of the GT-R world.

The RB26DETT is one of the iconic features of the Skyline GT-R and, like for every car, the beating heart of the machine itself. With an increasing number of models being imported overseas away from the local Japanese expertise, as well as many owners coming in possession of their car without clear service history I thought I’d put together a mini guide to spot common warning signals for engine trouble. This is very much a beginners version pointing at very common issues and aimed to a younger and less experienced audience which, judging by the number of inquiries I have received, is certainly increasing. Some of these tips are also worth assessing if you are planning to inspect a car before buying.

1 - Internal engine noise and irregular idling

Once the oil is up to temperature the engine should rev smoothly and have a slightly ticking sound when idle. Unusual noise could be caused by many factors, but, from a maintenance prospective, a healthy oil change cycle performed every 2,000km with quality products is a good first step towards issues prevention.

Abrasion of the surface coating on the conrod bearing is usually the first step toward failure: the idling noise itself should be somewhat smooth, which is a good sign of low attrition between the internals. For those who enjoy circuit driving on a regular basis an oil pan baffle is probably a worthy investment to avoid extra internal wear due to oil starvation. 

2 - Overheating 

Considering the price of a new engine block (N1 blocks are sold at over 400,000¥ today), taking some extra steps to prevent cracking due to overheating is something worth addressing in the early stage of ownership.

Rust and sludge can accumulate in the water even with lower mileage cars, so replacing timing belt, water pump and thermostat is a great first step to ensure better cooling. I have recently replaced all these items and the water temperature has been reading a couple of degrees lower than before.

3 - Boost loss

It’s not uncommon for owners to increase boost on their cars and, while this practice brings quick performance benefits it has also undoubtedly its drawbacks, namely increasing stress on the turbo shaft.

Standard (non-N1) BNR34 turbo blades are made of ceramic and a sudden loss in boost could possibly mean cracking/shattering, leading to massive engine failure. Seriously check for this issue if you are in the inspection stage of a new car purchase.

4 - Exhaust smoke

Few months ago I watched in horror a video posted on Facebook by a fairly famous dealer in Nagoya advertising a recently sold BNR34 in Midnight Purple II as it was on the way to its new owner in UK. The car was idling with noticeable white smoke coming out of the exhaust, and still plenty of people left comments on how the car looked and sounded great!

White smoke coming out the exhaust can be symptom of seal failure inside the turbines, possibly due to excessive boost. Turbines, like many other components, have a shelf life that is mostly dictated by usage and maintenance, and will need replacing if necessary.


The bottom line here is that most of the causes that lead to larger (and more expensive issues) can be prevented with basic maintenance and overall attention to details. The RB26 is a robust engine that can last for a long time without requiring overhauling, if properly maintained.

Until next time.

1 comment:

  1. thanks for the info just purchased my first GTR (R33) so first experience with the RB26 very good info here