Hey guys, So this is my first summer with the car here in central Texas and our lovely 100 degree temps are making me seriously eyeball my temp gauge. I know that 195 is where it's supposed to be, but mine creeps up past the 195 and at its hottest it seems to get about halfway between 195 and the next hash mark (there isn't a number there). This generally happens when I'm sitting, when I start to move again it starts going back down toward 195. Is this "normal" for these kinds of outside temps for my car? I did open the bleeder valve on the radiator and got some air out. I also opened the bleeder on the thermostat housing and nothing came out but coolant. I'm thinking maybe it just needed to be bled a little more? Or like I wrote above is this "normal" for really hot temperatures.
I would check the temp with an IR gun at the thermostat housing to see how that correlates to what the gauge shows/give you an idea of what the temp is when the gauge reaches the "high point." FWIW, the cooling fans on some current cars/motorcycles today don't activate until 215-220F. 195-220F is a pretty common range for engine coolant temps on street cars. NASCAR coolant temps are in the 280-290F range but that' a different application - don't try this at home!
Turn on your headlights and see if your temp gauge changes (goes higher). If so, it's a pretty good indication you have poor grounds. Ferrari gauges are not isolated from the 13volt system and are greatly affected by charging voltage and ground conditions.
Temp gauge is fine it seem. It's reading slightly cooler (5 degrees or so) at the thermostat housing, but no jumps when I turn on the lights or anything else. The car is fine as long as I'm moving. Once I sit, the temps just continue to creep up, which leads me to believe that the fans just aren't doing their job? I put in spal fans which are supposed to be a nice upgrade from the stock ones... but yeah sitting the temps just keep climbing. Could this also be a faulty thermostat?
The radiator will always have a small air pocket. It will never not bleed some air. I bleed mine when I fill it after service and never look at it again. Assuming all the usual stuff is OK. Radiators over time get an internal coating. Even rodding them out will not return them to 100% efficiency. Sometimes they just need to be recored. Your car is over 40 years old. That used to be unheard of radiator life. Antifreeze is not as efficient as pure water. In hot climates I used to run 25% antifreeze, 75% water and a bottle of Redline Watter Wetter. Be sure your fans are getting full alternator output voltage. Run a 1.1 bar cap. Be sure you have no hydrocarbons coming out of the cooling system with an exhaust analyzer. That would be an indication of leakage at the head gaskets. If that is happening you will never keep it cool and it will just get worse. If you do all of that it should survive central Texas.
The radiator is new, installed about a year ago or so. I am using 50/50 anitfreeze. I will drain some out and put in water. For the fans, I assume it should be somewhere around 14 volt? They're spinning their little hearts out though. Cap is 1.1 bar and is also new as well as the expansion tank and all of the hoses... all new. Could it also be a faulty thermostat? Here's where it reaches and generally stays if it gets "hot", where the red mark is... is this "too" hot or is this in an acceptable range? Image Unavailable, Please Login
FWIW, my '89 328 sitting in 100+F traffic ...The needle will go to maybe two needle widths past the 195 mark, then the fans activate and the needle drops to about 1/2 way between the 195 and the previous hash mark; the fans shut off. The needle will rise again to that point and the fans activate again. It will do that sitting still in such temps until the car runs out of gas! Assuming the gauge is showing some reasonable correlation with actual temps, based on needle position in your pic, it looks ok to me if that's the high point.
Yeah mine basically gets that high and stays there unless I start moving. From what I understand the 328s have a much better cooling system than the 308s... now why that is I'm not certain but that's what I've been told.
My 308 has survived 20+ years of Texas summers and have chased high temp indication for many years, slowly chipping away at it. Some of it has been electrical, some cooling system. It was 100 last weekend and it did well - stayed at 195 or below (my A/C did not perform like my radiator). That was after years of tweaking and sometimes seeing close to the 3/4 mark (indicated, not necessarily temp) Electrical: An IR thermometer is your friend in telling how much is gauge and how much is cooling system. Point it at the water pump just under the airbox and see what the temp is and how it compares to your gauge. That helped me see my gauge was off. Turn the A/C on and off. I was seeing my needle jump around - means grounding issues Had my water temp gauge replaced at one point Make sure both fans are on when the temp hits 195. - Had my radiator temp sensor replaced when they weren't turning on. IR thermometer is also your help here. Could also be the relays if it's not the temp sensor. Note that the radiator fan temp sensor is in the radiator - so it uses radiator temp to decide when to come on. The sensor for the dash temp gauge is on the engine itself. Cooling Installed a new radiator cap Upgraded radiator fans and moved them closer to the radiator Found a pinhole leak in the radiator outlet tube and then Installed an Aluminum radiator Replaced the foam on the hood that ensures air goes through the radiator Using 3:1 water to antifreeze with redline water wetter
I’d just say “Welcome to Texas” with seeing the water temps like that. I’d be perfectly happy seeing the gauge readings you have. Those are nowhere near out of normal. My 308 will creep when sitting too (I think most would) and I am doing the Spal upgrade when I get my car back from the upholstery shop next month. I had a potential overheating incident after getting my car back from a major service which turned out to be a stuck closed thermostat. If your temps go back down as you drive, that’s a good indication things are normal. I wouldn’t sweat it. Bad use of words since we’re discussing AC systems too, but I’d say you’re fine. We’re all mesmerized by new car temp gauges staying in one place and never moving. Not so with the older cars. Older gas gauges too. My 1997 Viper temp gauge is all over the place and is perfectly acceptable according to the manual. cheers Dave
