Before you noticed the low level in the surge tank when was the last time you checked the coolant level? If it was recently or you suspect any type of a coolant leak, a pressure test never hurts. Otherwise make sure that you regularly inspect the coolant level. And of course did your fans come on? On my car the cooling fans don't normally come on untill the needle is right below the same line that you're talking about. If I've read previous messages correctly, this is too high a temp for the fans to come on. If this is the case, then Fanzilla will NOT cure this. Fanzilla is a bypass for the factory installed relay that turns the cooling fans on. It helps to prevent a strain on the electrical system when the fans are powered up. Both Fanzilla and the factory installed relay/wiring are signaled by the otterstat for when to activate the fans. The otterstat is located in/on the coolant pipe in the engine compartment on the left side of the car. While the engine running @ this temperature isn't damaging, it does get robbed of power. Make sure that for your fans you have the upgraded circuit breakers and that you DON'T have the blue fan fail relay installed. Since you said when you picked up speed your temp went down, your radiator is fine. My car has the 3-layer radiator, no Fanzilla, 5/150 antifreeze (orange) and operates in around 115°-120° heat on a daily basis. That's the weather, not my coolant! And with the exception of the otterstat, everything works great! The next chance I get I will be driving the D over the hill thru Death Vally to REALLY put the radiator to the test! Procedures for flushing and refilling the cooling sytem can be found in the technical library. The instructions there are better then the workshop manual. Just remember to always use distilled water. Only use tap water in an absolute emergency! Regular distilled from the grocery store is just fine. "Scientificly Pure" water from the auto parts store is the same thing only more expensive. Unless you live in an area where the DeLorean will be exposed to freezing temps or extreme heat, a 50/50 mixture will be fine. I use a 65/35 because of the environment I'm in. As far as cooling efficiency vs. mixture, I don't know. But give Prestone a ring @ 1-800-862-7737, they should be able to tell you. If you have any other questions e- mail me. -Robert vin 6585 --- In dmcnews@xxxxxxxxxxx, "Sacha Prins" <sprins@xxxx> wrote: > Hi, > > The other day I noticed that the cooling reservoir of my DeLorean was > empty, since I was a long way from home I added 2 liters (0.5 gallons?) > of water which filled the coolant reservoir to the required level. > > Today I was driving in a traffic jam and suddenly the temp meter went > to 104C (which is the last white line on the scale) and that scared me > a bit. When I caught speed again the temp meter dropped to a more > regular level. On the way back there was no traffic jam so I could > drive home without any temp problems. ...............