All, I drove my 328 in modest traffic. Someone driving next to me said that I had a coolant leak; I just thought this was a standard expansion drainage (to bring level to nominal hot volume). When I parked, about a half quart or more coolant escaped onto the parking lot. This is an obvious problem. I drove home trying to keep lower revs an being gentile. Temperatures got high at idle but cooled during moving. After I got home and let the engine cool, I looked into the expansion tank. There was coolant but low level (about 1-2cm above the bottom); I had to fill with about a quart to get to the spec level (about 5cm from filler top). I ran the engine to hot and shut down when I saw a lot of coolant escaping again. I did not see the fans come on. This tells me that I may have one or more of these problems: 1) fan failure: Can someone tell me how to test the fans and the thermal switch? 2) failed expansion tank cap: Has anyone had one stick open? 3) air in coolant system: note that I have had excellent engine operation until now, so air would have been admitted into the system. 4) water pump failure: is there a way to check? Thanks all, Rob
Option 2, very common problem, just replace it. You want a 1 Bar (16PSI) cap. Its not that they stick open but more that the spring gets weak & won't hold the pressure any longer. Bleed the cooling system when you have the new cap on, you may have some air in there now if the level went down that far.
I vote for #2. Very common problem. Ferrari caps are not very good. I had a bad one right out of the box some years ago. Dave
If the engine got hot and the rad fans did not come on then your problem isn't the expansion cap. If both fans didn't come on then that suggests possibly the temp sensor. However, there's a possibility that you were running on just one fan and now the second fan has failed. In other words, it could be the fans themselves. The fans are easily rebuilt if you're handy in the garage - typically it's a matter of cleaning them up internally, replacing the brushes, and increasing the gauge of wiring going to the brushes. If you're not handy then you can buy replacements but don't do it through ferrari parts retailers, you'll save some money by buying the fans through a jaguar parts supplier (they're the same fan as on a vintage jag). Do a search for radiator fans and you'll find a step-by-step with pics for rebuilding the fans. As to radiator caps, they come in .9bar and 1.1bar versions - go with the 1.1bar version. Good luck!
