In the world of Ferrari maintenance, there arefierce debates about virtually everything, whether you’retalking about miles versus age when it comes to timingbelt changes or driving versus storing when it comes to collector cars. Of all the contentious topics, however, there’s onethat always stands out in my mind: that mysterious green fluid flowing through every Prancing Horse’s veins called coolant.
Without getting into the nitty-gritty, I’ll just say it sometimes seems like there’s more thoughtful debate around climate change than there is about cooling-system decay. There’s little need here to get into the subject of electrolysis and corrosion. For our purposes, let’s just says it’s something that happens and is impossible to prevent entirely, but the best way to slow it down is to service the cooling system every three years. This means flushing out all the old coolant and replacing with new. If you want to add a cooling-system conditioner such as Water Wetter, so much the better (though opinions vary widely there, as well).
To my knowledge, there’s not a single Ferrari that will not suffer some specific harm if its coolant isn’t flushed. The gearbox-to-cooling-system heat exchangers on F355s, 360s, and F430s, for example, are subject to settling debris and internal corrosion. The large metal radiators that keep frontmounted V12s cool can corrode inside and leak at the welds. If one of those weak welds makes contact with a speed bump, what was once just a green hue can easily become an active drip.
During a cooling-system service, it’s important to drain as much coolant as possible.That means all radiators must be drained (the mid-engine V8s havetwo, located up front), and here at San Francisco Motorsports we always pull theengine block drain and at least one of the major coolant hoses attached to theengine.
No matter how and where you drain, however, refilling is the most important part of the job. Because of this, I think using a vacuum filling system is a necessity. (Sorry, DIYers: This may be the one specialist tool you absolutely have to buy. Otherwise, bite the bullet have a shop so equipped do the job.) The main reason vacuum filling is so important is that there are many internal passages and high spots that can trap air so that it will never bleed out on own. Furthermore, the airbleed screws on F355s, Testarossas, and earlier cars cannot be trusted; they are often nearly welded closed [WHY?], and the soft pipes they are braised or pressed into can easily be damaged.
What happens if you have air trapped in the cooling system? Consider the 360. The Modena’s cooling fans do not run based on a sensor on the engine block, but based on a fan switch on the right front radiator. Air can easily be trapped in that exact spot, causing the fans to never run or to run too late— your only clue something’s wrong will come when you spot the engine-temperature gauge climbing into the red.
Coolant is only part of the coolingsystem story, however. On 1990s and earlier models, such as the 328, F355, 550, and Testarossa, electrical issues often cause problems. On high-amperage circuits such as blower motors, radiator fans, and fuel pump(s), I commonly find fuse-board failures, so when in doubt, test the fuses. The second most common reason cooling fans don’t work is poor wiring contact at the fan switch or a failed switch.
One problem that’s starting to crop up regularly is imbalanced cooling fan blades on F430s. This can be severe enough to vibrate the steering wheel when the car is idle. I’ve disassembled them to look for chips, pits, or even tire clag, and found nothing, and so far attempts to rebalance the blades have failed. The only cure appears to be replacing both fans.
Source: Forza Magazine - ShopTalk (November 2018 - By: Jesse Westlake)