Problems with Cali T gearbox?

OK, I need to point this out. You say "I don’t disagree that popping the hood doesn’t help." - that is a TRIPLE NEGATIVE, a confusing indirect way to say something potentially very simple so let me see if I understand that sentence...

"I don’t disagree" - means YOU AGREE.

"...that popping the hood doesn’t help." - means popping the hood is of NO USE.

Therefore your sentence actually means "you agree popping the hood is of no use".​

However, you then proceed to say "Actually it makes a lot of sense and can’t be a “bad” idea." which appears to be contrary to what you meant in saying "I don’t disagree that popping the hood doesn’t help.".

Sorry, but I am not sure what you were trying to say here.

 

You appear to imply I said ALL DCT failures are caused by commuting in traffic jams. That's not what I have been saying.

What I have been saying is that excessive heat will accelerate the aging of mechanical components and that DCT failures do tend to be associated with heat - that's why Ferrari installed a much bigger heat exchanger for later Cali models. For early Calis, that implied that inadequate DCL heat exchangers was deemed by Ferrari as a cause of DCT failures.

I also say commuting in heavy traffic will expose the car to more heat. Heat dissipation is what the larger heat exchanger is designed to improve. I also say the car does a better job of heat dissipation when it is moving at a reasonable clip. I then go on to say I avoid taking my car on trips that will involve slow-moving traffic.

I leave readers to make their own conclusions.

If you agree that heat is a major factor in DCT failures I would hope you also agree it would help if drivers also not make matters worse by compromising the workings of the DCT coolant radiator. If the car isn't moving through the air, the DCT coolant radiator won't receive fresh cool air as it's located in front of the hot engine, near the even hotter engine radiator.

I would hope but I'm not sure if Getrag will ever provide more reliable sensors and even if they do, the sensors in the current cars will have to fail before they get replaced so that's not entirely a comforting thought.

Finally, I suspect only a minute sample of all CaliT owners are on FChat and of that population, only a few post their negative DCT experiences but it is encouraging that there are not more reports of DCT failures. Do keep in mind CaliTs are also a few years newer.

 

I think you make an excellent point about the longer delivery and return paths to and from the DCT radiator. It's probably compromising the cooling process. Short direct connections would work better and that is the case with the 458's setup. I also believe only the 458 Challenge uses a DCT heat exchanger, possibly because race conditions creates more heat in the DCT and the coolant used in the DCT radiator may work better as a radiator coolant than the DCT coolant for some reason. Regular 458s do not have DCT heat exchangers between the DCT and its radiators - they use 2 DCT radiators, one on each side, not 1 (double-layer) radiator (in the Cali).

As for the larger coolant volume imposed by longer delivery and return paths, I think a greater coolant volume actually helps to keep things cooler. It can act like a heat sink. The bigger the heat sink, the more heat it can absorb. However, the greater coolant volume also needs to be efficiently cooled and be matched by a large-enough heat exchanger and a large-enough coolant radiator. If those components are too small, the larger coolant volume will instead become heat POOLS or reservoirs, backed up at the choke points created by heat exchangers and coolant radiators too small to expedite the cooling of the coolant.

In essence, the whole system needs to have properly-matched components.

 

An FChatter (in Australia?) addressed the cooling issue by replacing the factory radiator with one with greater cooling abilities. Great idea.

 

I did look into that one at the time. That was a pre-2013 Cali and they either replaced the original (tiny) heat exchanger or added the newer large heat exchanger that Ferrari introduced in 2013. It is otherwise a huge job to re-engineer the oil radiator. The cooling system bottleneck in the older Cali is the tiny heat exchanger, not the radiator.

 

Let’s compare the cooling systems between the 458 DCT and the early Cali DCT.
If we just consider the plumbing, the length from the DCT to the radiator is at least 7 feet in the California. The pipe length length for the 458 is probably about one foot.

If the diameter of the pipe is the same, the resistance to flow is 8 times the difference in the length!

The pipe is the bottleneck.

The way to overcome this is to use a much stronger pump, enlarge the pipe diameter and / or shorten the pipe and increase the cooling capacity of the radiator.

The 458 uses 2 radiators which are fed by short pipes—superior cooling design.

 

I agree, the shorter distances afforded by the 458's mid-rear engine layout do present natural advantages. Not only with the DCT radiator circuit being more efficient, but the shorter exhaust system and lack of a long drive shaft also add to greater efficiency, better responsiveness. It's actually quite amazing the Cali, also being heavier, with 0.2 L less engine volume, is till able to perform so well in comparison. Of course, some of the positive benefits of the Cali's front-mid engine layout are the 2+2 seating and larger cargo capacity. There are PROs and CONs to both designs. The Cali's GT layout is also used in all of the factory's V12 cars.

I suspect the factory designers engineered the Cali's DCT cooling circuit to perform within a certain range of cooling efficiency so while you are correct in pointing out the more restrictive nature of longer plumbing, the designers would have already factored that in, by basing their design on the resulting cooling efficiency. However, having said this, I think they underestimated cooling requirements in the cooling circuit design they used for the earlier Cali.

I would also like to add that should the current cooling circuit prove to be still inadequate, your suggestions to increase cooling capacity would be the way to go, but we also have to keep in mind the impact of added weight, added power draw and having to find the space to put the bulkier system... in a future car model.

BTW, from my study of the 458's DCT cooling circuitry, it appears to just use DCT fluid as the coolant, as there is no heat exchanger (except in the case of the Challenge 458).

 

Had the same issue on my 2015 California T when it was a year old, around 6k miles. Had to take it in for service about 5 times before they figured it out. The repair took several weeks.

 

Here you go MalibuGuy, a screenshot off a Mischa Charoudin Nürburgring video review of the new Renault Alpine A110 published on Sunday... apparently the attempted review was foiled by weather.

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If you watch the video, you will notice Renault has been doing a helluva better job than Ferrari providing relevant car systems data with much cheaper cars. I hope the guys in Maranello are taking notice of the Alpine's twin clutch data display.

Oh well, at least they get the engines right.

 

I have a little more to add to this discussion.
I suspect that the coolant fluid pump is driven by the serpentine belt.

If so the idle rpm may affect cooling. If cooling flow is already modest, a low idle is actually worse. A slightly higher resting idle would theoretically be better.

So if you had been accelerating hard and shifting at high rpms which would generate more internal heat in the DCT and then you have to brake and idle at the stop light, your DCT can overheat.

Add to that a software strategy which reduced pumping at low rpms in order to address early complaints from owners sensitive about the hydraulic noise and vibrations emanating from the cooling system!

The engineers did not appreciate these details!

 

Michael,

Just a quick note if I may, not to derail this wonderful debate we're having here regarding the California's cooling and DCT.

Being a fan of the California and a 458 owner, I would love to know more about your study on the 458's DCT cooling circuitry. Is it available online somewhere so I can read it and educate myself?

There is also talk that the 2010 and 2011 458s are more prone to DCT failures than later models (2012-2015). If cooling hardware is the same and stayed the same until end of production, then alledged failures on pre-2012 cars are more of a myth than reality, with no scientific backing.

Thank you.

Kind regards,

Nuno.

 

MalibuGuy, thank you for your additional insight on this topic. I think you make some excellent points.

I agree it's most likely the DCT radiator coolant pump is driven by the engine's serpentine belt. Your concerns regarding how this design could contribute to DCT overheating seem to be well-reasoned. Regarding these concerns about the circulation of DCT coolant I also want to highlight the radiator fans themselves also play a big role in radiator cooling.

As you alluded, engine coolant temperatures do not necessarily correlate with those of the DCT; so if the radiator fans are only activated by monitoring engine coolant temperatures, the DCT would clearly not be adequately protected from overheating. At the moment, I don't know if DCT (coolant) temperatures have any role in controlling the radiator fans. What I do know from driving my Cali30 is that when engine coolant temperature gauges wander into the above normal readings I will notice the fans coming on when I idle the car. I'm just not sure if elevated DCT coolant temperatures can also switch the fans on.

As you pointed out earlier, it would really help if DCT coolant (and clutch) temperatures were displayed to the driver, just like the oil and water temperatures for the engine. The driver would then be able to tell if and how often the DCT is exposed to abnormal heat and if radiator fans come on when the DCT is (apparently) starting to overheat.

Finally, I think it's just a good idea to cool down the car after a drive or after having to idle or wade through very slow traffic. Just drive the car for 5-10 minutes at a leisurely pace without pausing unduly. I always do that in my neighbourhood before I park the car, and then I always pop the hood. For people who have to store the car under very hot conditions, I might also suggest running a fan at the rear of the car to cool the DCT which is just forward of the rear diffuser.

I know my views may come across a bit extreme but I don't run a racing team or a service garage so I have to take care of such matters myself, to avoid having to budget for avoidable equipment failures. IMO, these cars are all engineered on the bleeding edge and should be treated accordingly. I have, over my lifetime, owned and ridden on high end racing bikes and while they can be used on a daily basis, they are definitely very "high maintenance" and require attention and respect. I believe it is the same philosophy with Ferraris. You cannot treat them like a Honda Civic.

 

Hi Nuno, thank you for your message.

I used to have a BMW 540i Sport, which was a very popular driver's car, a bit of a cult car. It was also much more approachable from a DIY perspective, so it was fortunate that we could afford a BMW shop manual or just buy the less expensive (Bentley Publishers) version. Unfortunately, nothing like that exists for a Ferrari owner unless you possess the wherewithal, technically and financially, to purchase (subscribe to) something from The Ferrari Techinfo Bookstore.

My insights into the 458's DCT cooling circuitry come from analyzing parts diagrams from parts suppliers and asking questions on FChat. Here is a thread I posted on the Challenge 458 Forum about 4 months ago. I described some observations I had made from diagrams and asked about the Challenge 458's extra heat exchanger, receiving a helpful reply from an expert on the matter. While this does not answer your concerns about the earlier 458s possibly being more prone to experiencing DCT failures, it does confirm an understanding of how the 458 DCTs are cooled.

Addressing your concerns about the DCTs in the early 458s, I think it's very likely related to the same issues that were exposed by the early Calis because they all used the same Getrag 7DCL750. The Cali was the first FCar to use that DCT and was meant as sort of a "guinea pig" for that technology, if you may. We know early DCTs failed due to degradation of plastic zip-ties that proceeded to chafe and short-circuit the electrical wires. As a fix, those zip-ties were modified and/or relocated. I suspect the early 458s were exposed to the same zip-tie problem so if that's correct, early 458s would definitely be more prone to DCT problems... BUT, it's not due to a cooling issue. You can determine if an early 458 still has the old zip-ties or have been serviced (failed and replaced), from build dates and examining service records.

As regards cooling, the DCTs in the early Cali did suffer from inadequate cooling due to use of a too-small heat exchanger and that was fixed 2013 onwards with a much bigger heat exchanger, which is also used on other front engine FCars, like the V12s; but not in the 458. The 458 except for the 458C, did not use a heat exchanger, and has a much better DCT cooling circuitry for several reasons...

• the (2) DCT radiators appear to be bigger than the Cali's,
  
• each 458 DCT radiator has a dedicated fan (see below)
  
• and the DCT coolant plumbing is also much shorter as the DCT radiators are located behind the driver, not in a front engine bay.

The 458C is an exception, needing a heat exchanger, because obviously those cars are ALWAYS driven much faster than a regular 458 and they take many, many corners in a race; meaning their DCTs would be constantly shifting gears up and down, often many times for EACH corner. So their DCTs ran much hotter, necessitating the heat exchanger, which probably circulated radiator coolant much faster than the DCT coolant that exchanged heat with the radiator coolant in the heat exchanger. The faster a coolant circulates, the more efficient the cooling.

So, I hope I have answer a bit of your question.

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Michael,

Indeed you have, to a very big extent. Extremely informative and helpful. Thank you very much for taking the time, your knowledge on the matter is extremely impressive and it's a pleasure to learn from you.

Kind regards,

Nuno.

 

Thanks Nuno. I really do not deserve the compliment but I appreciate your encouragement.

 

Can anyone recommend a transmission shop for 2016 Cali T up in Long Island/NY area?

 

Please tell us what the problem is. Cali T transmission issues seem very rare and I bet every one of us owners here would like to hear what fails.