Coolant Reservoir Obstruction

By now we should all be aware of the benefits of silicone coolant hoses for the 550. Dave Helms sells the appropriate silicone hose kits and pictures obstructed original rubber hoses on his website:

http://www.scuderiarampanteinnovations.com/solutions.html#coolant

I was experiencing intermittent high water temperature readings last October so I decided to have my scheduled major service performed a month early. I had the temperature sensors and sender changed at that time. The problem, however, persisted.

The coolant return hoses to the reservoir tank were replaced several years ago with silicone hoses Classic Coach uses for their Challenge cars. The fan relay was replaced 18 months ago. That left the water temperature gauge and thermostat suspect. So I brought my car back to the shop.

The temperature gauge was OK. The thermostat tested faulty and a new thermostat was tested and installed. During installation, I asked the technician to check the coolant return hoses for clogs. The silicone hoses were clear. What we found was a partial obstruction in the reservoir pipe where one of the hoses attached. The reservoir was removed and cleaned internally.

I test drove my car extensively on Saturday at all speeds and idle times. I changed the HVAC temperature settings a few times as well and the water temperature fluctuations were within normal limits.

My 550 has had the coolant changed yearly since new with distilled water added to yield the appropriate ratio. Even with this amount of care, a corrosion clog was able to form.

So the recommended coolant hose upgrade, I feel, should include a thorough examination of the reservoir tank.
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FBB and Terry,

Yes, the tank appears to be an aluminum alloy. Some scrubbing with baby bottle and test tube brushes and the inside of the tank cleaned up nicely. I think removal of the reservoir tank, examination, and cleaning prn should be part of every coolant change.

It was nice to see the Challenge silicone hoses not developing any corrosion plaques over the past five years. Dave Helms' silicone hose kits are a must to install.

The thermostat was a little slow to respond so it was changed. I appreciate my technician checking the new one for proper operation prior to installation.

Barry
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Annual coolant (Shell GlycoShell) changes mixing with distilled water from 2001-present. The first owner serviced the car at a different facility, 1999-2001

 

This is a 12 year-old car with ~67,000 miles. The corrosion plaque, as I called it, was just that; a vegetation on the inner surface of that pipe. Peeling paint on the outer surfaces of the pipes make things look a bit worse than it actually was.

But despite its age and mileage, my car has been meticulously maintained and perhaps over-serviced with more frequent fluid changes for track events. We're careful to keep the coolant-distilled water ratio at 1:1
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Terry,

Classic Coach is a Ferrari Factory authorized service facility so they use GlycoShell. We'll just have to keep an eye on this in the future. The failing thermostat was no doubt contributory. I'm just glad the problem was found and corrected.

Barry

 

Right, Terry. For me it winds up yearly coolant and transmission oil changes, and the brake fluid is changed prior to each track event.

Barry

 

I tried to describe the corrosion deposit as best as I could. And I had hoped my pictures would be illustrative. Internally, the tank was relatively clean. It was just that one particular pipe connected to the hose from the top of the radiator that was involved. It was only a partial obstruction. You didn't have the tank in hand to see this for yourself.

All the return hoses were free of deposits. And, as I mentioned, I think the faulty thermostat also contributed to my car's symptoms.

Distilled water has always been used in my cooling system. I would say that the first owner's dealership, Ferrari of New England, used distilled water too in the one coolant change that appears in his service records.

I think FBB's explanation of dissimilar metals accounts for what was discovered in my reservoir tank. It seems that this particular area of the reservoir is prone to corrosion deposits in these cars. Perhaps the construction of the tank in this area has to be investigated further.

Brian, for years now I've paid close attention to your posts and learned much about my 308 and now my 550. Your thoughts and advice stem from many years of experience with these cars. We, here, benefit much from you, Dave Helms and certain others. I've even archived several relevant threads where your advice was significant.

One of the reasons I asked my technician to check the return hoses is what you and Dave said here just last summer:


http://ferrarichat.com/forum/showpost.php?p=139762286&postcount=21

http://ferrarichat.com/forum/showpost.php?p=140180282&postcount=23


I showed my technician the pictures Dave Helms posted. I think Classic Coach learned a little more this past week.

FBB, I drive my car year-round and need effective antifreeze up here in the Northeast. The tracking I do is White Group and I really don't overstress my car. It's two tons of metal that I'm driving around the track and I have to think two turns ahead. There's no safe alternative to the way I drive my 550 on the track; conservatively. I'd like to drive an intact car home at the end of the event and go to work the next day.

Even with 50/50 antifreeze and water, my 550 runs normal temperatures at the long tracks I go to. Hopefully you'll get your 550 to the track soon and see just how well the 550 behaves.

Barry

 

I'm puzzled too, Brian. It was just that one pipe that was involved internally. The one next to it which accepts the hose from under the plenum did not show any deposition internally but was corroded a bit on the ouside where the paint had peeled.

I posted this to alert 550 owners planning on installing Dave Helms' silicone hoses to have their technicians remove and examine the tank. My pictures also serve to show what silicone return hoses look like five years after installation.

Barry

 

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