4.0 Liter V8 Turbo Engine Potential Problems
#1
4.0 Liter V8 Turbo Engine Potential Problems
This is my first post in the Bentley forum as I have become a first-time owner of this amazing marque in June, 2018. I purchased a 2015 Continental GTC V8S with 5,000 miles this June and what a car! The exhaust sound with the sport exhaust option is simply sublime. I drove the car over 1400 miles during my first week of ownership. My wife and I attended a high school graduation in Minnesota, a wedding in Wisconsin and a funeral in Illinois within that week, and this was the perfect car for those occasions. The highway miles rolled by effortlessly and the fuel economy was a respectable 23 mpg overall. I thought fuel efficiency was my primary reason for getting the V8, but believe me, the exhaust note has leaped above mpg for reasons to own a V8 Continental GTC!
I started doing research on the hot-V twin turbo V8 supplied by Audi and this is where I wished I had done my home work a little earlier. According to posts in various Audi forums, 90% of the components in the Bentley mill are shared by Audi the 4.0 V8 mill found in the Audi S8 and S7. [The turbos on the Audi R8 and RS7 are different and thus have not experienced failure] There have been several engine failures caused by premature failure of the turbo impellers. The shards of metal make their way into the engines and cause severe internal damage. The engine might feel rough, there might not be a CEL, and ultimately it will not start. The fix after the damage is engine replacement and new turbos. This is about $40,000 - $45,000 for the Audi products, so I suspect Bentleys will be costlier. Incidentally, one recommendation is to replace the existing turbos with the ones found in the R8 and RS7 since they have not failed.
I'm posting here to see if anyone with a higher mileage 4.0 V8 engine Bentley (Continental or Flying Spur) has suffered such catastrophic failure.
I started doing research on the hot-V twin turbo V8 supplied by Audi and this is where I wished I had done my home work a little earlier. According to posts in various Audi forums, 90% of the components in the Bentley mill are shared by Audi the 4.0 V8 mill found in the Audi S8 and S7. [The turbos on the Audi R8 and RS7 are different and thus have not experienced failure] There have been several engine failures caused by premature failure of the turbo impellers. The shards of metal make their way into the engines and cause severe internal damage. The engine might feel rough, there might not be a CEL, and ultimately it will not start. The fix after the damage is engine replacement and new turbos. This is about $40,000 - $45,000 for the Audi products, so I suspect Bentleys will be costlier. Incidentally, one recommendation is to replace the existing turbos with the ones found in the R8 and RS7 since they have not failed.
I'm posting here to see if anyone with a higher mileage 4.0 V8 engine Bentley (Continental or Flying Spur) has suffered such catastrophic failure.
#2
I work for a dealer in south Florida and have been with the brand longer then the v8 has been around. Honestly In my experience it has been a good power plant. I have had a few out for oil leaks but that’s to be expected. Based on failures I see down here the convertible tops are far more worrisome then the engines.
#3
I work for a dealer in south Florida and have been with the brand longer then the v8 has been around. Honestly In my experience it has been a good power plant. I have had a few out for oil leaks but that’s to be expected. Based on failures I see down here the convertible tops are far more worrisome then the engines.
The Audi 4.0 Liter V8 was introduced to some 2013 Bentley Continentals and Flying Spurs, so it has not been around that long. Far fewer Bentleys use this engine, and specifically, the turbos, than the Audi products with the similar engine. Although I do not have data, I would venture the Audis are racking up more miles than Bentleys. Hence, the reported turbo failures with these engines is presenting itself with the Audi cars first.
The sky isn't falling, but it is imperative that consumers know if a potential problem exists. Ill continue to enjoy my '15 GTC V8S, as I continue to check in on my Audi brethren.
#4
The Audi 4.0T turbo failures due to the clogged turbo oil supply screen affects the Audi 4.0T S6, S7, RS6, RS7, S8, A8 and Bentley 4.0T.
There is a turbo TSB for Audi (2013-2017): 21 Engine difficult to start, turbocharger damaged, V8 4.0TFSI, 2044640/4 May 22, 2018.
This is also a TSB for Bentley 4.0T (2012-2018): Engine difficult to start - Turbocharger damaged - V8 4.0TFSI, Bentley, 2052085/1
There is a turbo TSB for Audi (2013-2017): 21 Engine difficult to start, turbocharger damaged, V8 4.0TFSI, 2044640/4 May 22, 2018.
This is also a TSB for Bentley 4.0T (2012-2018): Engine difficult to start - Turbocharger damaged - V8 4.0TFSI, Bentley, 2052085/1
Last edited by m327; 07-09-2019 at 09:41 AM.
#6
I should add to this, generally these engines are very reliable and I may go so far as to call them bulletproof. I have seen some with 100k+ miles with only small oil leaks from the normal places. The turbos have been very reliable especially if short interval synthetic oil changes are performed.
These engines, along with many other modern day engines are very very dependent on hydraulics. Say the turbos, hydraulic lifters, cam phasers, HPFPs, and other internals.
With that said, short interval in my opinion is 5,000 miles - 7,500.
Thanks for reading my rant, I'm just a huge fan of these engines. Great power, sound, and reliability.
Cheers
Rob
These engines, along with many other modern day engines are very very dependent on hydraulics. Say the turbos, hydraulic lifters, cam phasers, HPFPs, and other internals.
With that said, short interval in my opinion is 5,000 miles - 7,500.
Thanks for reading my rant, I'm just a huge fan of these engines. Great power, sound, and reliability.
Cheers
Rob
#7
Yes, as long as the turbo oil supply screen does not get clogged, which can cause rapid turbo failure. On some cars, the cascading turbo failure damaged the engine and it required a replacement. Typically the charge cooler catches most of the failed turbo debris. So far, there are 68 Audi C7 cars with 4.0T turbo failures due to clogged oil supply screen on the Audizine forum 4.0T turbo fail poll.
The 4.0T short block is very stout.
There are issues with the cam adjusters on some of the 4.0T engines, see this Audi ATU 2018: https://static.nhtsa.gov/odi/tsbs/20...50761-9999.pdf
Also the PCV (oil seperator) can fail around 50k miles and produce a load squealing (2017 & earlier), it is mounted just above the offending turbo oil supply screen. Audi has increased the PCV (oil seperator) warranty to 120k miles on that part due to this weakness.
https://static.nhtsa.gov/odi/tsbs/20...45089-9999.pdf
The 4.0T short block is very stout.
There are issues with the cam adjusters on some of the 4.0T engines, see this Audi ATU 2018: https://static.nhtsa.gov/odi/tsbs/20...50761-9999.pdf
Also the PCV (oil seperator) can fail around 50k miles and produce a load squealing (2017 & earlier), it is mounted just above the offending turbo oil supply screen. Audi has increased the PCV (oil seperator) warranty to 120k miles on that part due to this weakness.
https://static.nhtsa.gov/odi/tsbs/20...45089-9999.pdf
Last edited by m327; 07-13-2019 at 12:21 PM.
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#8
By the way, there is an aftermarket external oil screen kit to replace the 4.0T V8 internal turbo oil supply screen that gets clogged. They are selling faster than JHM can make them.
Stainless Braided Turbo Oil Line and Strainer/Screen Relocation Kit (JHM-Serviceable) for TSB-2044640 on C7-D4 4.0T
"This product was designed to make your life easier, save you money over the long run, and help keep your turbos alive. This is the solution to the pesky OEM Oil Strainer/Screen that gets clogged over time which inevitably starves your turbos of oil (TSB-2044640). When your turbos are starved of oil they will fail which will cost you thousands of dollars to replace. With our JHM Stainless Braided Turbo Oil Line and Strainer/Screen Relocation Kit, you no longer use the factory Oil Strainer/Screen (079115175G) and instead uses two oil screen filters that are relocated on top of the motor where they are easy to get to and can be serviced as often as you like! To replace your OEM Oil Strainer/Screen is a lengthy process which requires you to put your vehicle into service position, remove the throttle bodies, intercooler, bi-pipes, oil separator, etc. just to get to the screen. With our kit, you only have to perform this job ONCE saving you this costly service every time you want to clean your filters. "
Stainless Braided Turbo Oil Line and Strainer/Screen Relocation Kit (JHM-Serviceable) for TSB-2044640 on C7-D4 4.0T
"This product was designed to make your life easier, save you money over the long run, and help keep your turbos alive. This is the solution to the pesky OEM Oil Strainer/Screen that gets clogged over time which inevitably starves your turbos of oil (TSB-2044640). When your turbos are starved of oil they will fail which will cost you thousands of dollars to replace. With our JHM Stainless Braided Turbo Oil Line and Strainer/Screen Relocation Kit, you no longer use the factory Oil Strainer/Screen (079115175G) and instead uses two oil screen filters that are relocated on top of the motor where they are easy to get to and can be serviced as often as you like! To replace your OEM Oil Strainer/Screen is a lengthy process which requires you to put your vehicle into service position, remove the throttle bodies, intercooler, bi-pipes, oil separator, etc. just to get to the screen. With our kit, you only have to perform this job ONCE saving you this costly service every time you want to clean your filters. "
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