Monday, July 10, 2017

Maintenance Issues on the Bentley GT Series

The GT is without a doubt best engineered and most successful modern car in Bentley’s history.  The GT is the first Bentley designed by a full engineering team, using one foundation (VW powertrain engineering.)  The days of grafting together parts from other car lines came to an end with this groundbreaking vehicle.



That said, it is not without its problems as we are beginning to discover.  In an earlier review I described the GT series as generally reliable.  While that’s true, we are seeing the emergence of some issues that will carry a noteworthy repair cost and affect a significant percentage of cars.  None of the things in this article worry me terribly but owners should be aware of them, and prepare for the costs.

Before describing these issues I should say that they are fewer in number, and lower in cost, that the issues that befall earlier products from Crewe.  Shadow/T era cars are infamous for hydraulic problems, and the Turbo/Spur successor line is not much better.  All the Crewe designs are more prone to leakage and generally a lot less reliable.

The GT line is less maintenance intensive than any prior product from Crewe.  Given that, the only reason these things are of any concern is related to the success of the cars.  Most older Crewe-era Bentley were sold to repeat buyers who know what to expect.  The GT drew a huge number of new owners into the Bentley fold and many of them had no prior experience with a car of this caliber.   That is particularly true of the people who are buying early GT models on the secondhand market. 

That fact is, whatever you pay for a Bentley GT, they are still expensive cars to fix, and potential buyers should know that going in so that they can put asking prices in proper perspective.  Existing owners should know how to recognize when they are being treated fairly, even as they are told their car needs expensive work.

The first problem we saw was with convertible tops.  The stay cables stretch, snag, and break.  The result is a top that does not fold correctly when lowering, which ultimately bends the frames.  The cure:  A new top assembly for a parts and labor cost of near $20k. 

Over the past few years I’ve heard from quite a few frustrated Bentley owners about this topic. Yet tops have been a trouble spot on Bentley cars since the first introduction of high pressure hydraulics with the 1994 Corniche.  Azure tops experienced failure of lines and actuators, and all those cars are facing top repairs in the same cost range as that cited for the newer GT line. 

Here’s what I take away from that:  It’s hard to engineer a fully automatic convertible top.  In the convertible world, the Bentley tops are among the biggest, so they put the most stress on hydraulic lines and actuators.  Top reliability is complicated by the fact that weaknesses tend to show up years later – after the car is out of warranty – and the permanent “fix” – re-engineering for longer life – is seldom undertaken.

 The next problem we are seeing is with engine externals.  With the introduction of the GT Bentley embraced a manufacturing process that involved building up the complete engine and them raising it into the car from below.  The fit is so tight that some simple-sounding repairs now require engine removal. 

In particular, the vacuum and hose harnesses are breaking down from heat and age, and they cannot be replaced without engine removal.  This turns a seemingly simple job into a near-$10,000 repair.

On a lesser scale, the packing density of the engine bay complicates many if not most service procedures.  Hundreds or thousands of dollars are added to the costs for water pump, spark plug and other common parts replacements for the difficulty of access.

Many carmakers embraced multiple turbochargers as a way to increase performance without traditional turbo lag.  Bentley is no exception.  Those turbos are great when they work but as the cars accumulate miles we see more issues with waste gates and boost control, and the solution is once again to remove the engine for access.  Turbo problems are another items with a five-figure repair cost.

Some lovers of the old technology would point out that turbos were virtually trouble free on the earlier Crewe-designed V8 engines. While that’s true those motors also became notorious for blowing head gaskets and in some cases whole engines from excess turbo boost.   

If we consider those as turbo-related failures then the cost of the GT’s turbo problems are similar or less. 

For as long as I can remember Bentley and Rolls-Royce called for replacement of brake hoses every 5-10 years.  Other high-end car companies have similar maintenance requirements.  Today’s GT asks for the same kind of maintenance, and the cost of this job is about $5k most places, at current prices.  This is actually less than the comparable job on earlier series cars, and yet owners express surprise when we report the need.

As these cars age we are seeing their air suspensions fail in a predictable pattern.  First one airbag or line develops a small leak.  This causes the car to change height slowly whenever it is parked.  This movement accelerates sensor wear, but more significantly it strains the compressor which soon wears out and sets "slow to pump up" faults.  People think the compressor is the only problem but they are not fixing the underlying issue till they fix the leaks.  When they change a strut that shows them how worn the other struts are by that time (as evidenced by ride) and the cure ends up being a compressor, o rings, new struts and maybe some other parts.  The bill:  Well over $10k.

When people complain about that I point them to the same costs on an S-Class Mercedes, or the even higher costs to do struts and springs on the previous generation of Bentley Continental.  The same can be said for control arms, ball joints, and other front end components that wear out a lot quicker than many owners would like.  Seldom will a front end in one of these cars have the durability of a Chevy pickup, despite their vastly greater cost.  All I can say by way of explanation is that performance and exclusivity have their price, and Bentley suspension work pales next to comparable work on most Ferrari or Lamborghini.

The cost of cosmetic repairs continues be higher on Bentley than on other mass-produced cars.  The reason for this is simple:  Bentley interiors are made of nicer stuff, and they are more like fine furniture than most cars.  Where a Toyota has a plastic panel, the Bentley has wood.  Bentley leather is softer and smells better than vinyl from a lesser vehicle, but it won’t last as long in sun and moisture. 

None of these things are expensive enough to stand out when we look at Bentley service costs over the past 30 years.  They are just the latest iteration of issues that make up the costs of Bentley ownership.

Reliability of Bentley cars has increased quite a lot over the past 30 years.  Intervals for oil changes, spark plug replacements, and other common service have been extended without reduction in the system lifespan.  All Bentley models are less leak prone than at any time in the past.   Parts like brakes and tires deliver levels of performance that would have been impossible a generation ago, with similar and sometimes greater lifespans. 

Bentley GT electronics warns us of low tire pressure, low engine oil, and a host of other potential problems.  Modern display technology shows warnings in plain text (English for most of us) which is far more effective than the oft-indecipherable idiot lights of years past. 

Updates and module replacements add cost when compared to older cars, but when compared to costs for similar high-tech vehicles there is nothing on these cars that stands out.  The technology in Bentley is shared to a significant degree with high end offerings from VW/Audi so the updates mostly follow patterns set in those higher volume car lines.


When put in historical context the cost of maintaining and repairing the GT series is in line with or lower than previous offerings from Crewe.   In other words, it’s expensive.  And you get what you pay for, with a standard of luxury and performance unmatched in other cars.  My suggestion is that you follow the same rule of thumb I've offered when buying an older car from Crewe:  Budget at least $10k to put your new purchase into shape, plus cosmetic repairs.  $20k is high but not surprising. Then plan on $5-10k for annual upkeep cost.  When year hear someone say “I drove this car two years and never had to do a thing . . “ remember there is no free lunch, and that person has (unknowingly or not) simply deferred a considerable amount of maintenance and that falls on you if you’re the new owner.

John Elder Robison

(c) 2017 John Elder Robison
John Elder Robison is the general manager of J E Robison Service Company, celebrating 30 years of independent Bentley, Rolls-Royce, BMW/MINI, Mercedes, and Land Rover restoration and repair in Springfield, Massachusetts.  John is a longtime technical consultant to the car clubs, and he’s owned and restored many fine British and German motorcars.  Find him online at www.robisonservice.com or in the real world at 413-785-1665

Reading this article will make you smarter, especially when it comes to car stuff.  So it's good for you.  But don't take that too far - printing and eating it will probably make you sick.

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