hi guys, on starting and at tickover the temp raises past normal, up to the danger area, but the radiator does not get hot, hence the fan doesnt come on... does this just sound like a sticky thermostat, if so what else uses the same one, as i dont have a ferrari dealer within 80 miles.... fiat/alfa possilby?? cheers steve j
Mine did the same thing. I bled the rad, but still no good. Turned out to be that the coolant was about a gallon low. I thought I was measuring it correctly- but I was not. If you put in too much coolant/water, the car will equalize itself through the tank cap. Easy fix. Do any of the hoses at the radiator get warm at all? If not- it could be the thermostat. Feel the upper and lower as it's warming up. Also- leave the cap of the coolant tank and see if it's circulating in there while it's starting to overheat. If the thermostat is stuck closed- I would think that nothing will be flowing. Good luck
Steve, make sure that you've thoroughly bled the radiator. An air pocket can keep the fan switch from operating. The first time I changed my coolant ( and , ahem, didn't know what I was doing) the exact same thing happened to my '85. After properly bleeding and topping off the coolant, everything went back to normal. Good luck.
Steve -- You might also try cracking open/bleeding at the bleed screw on the thermostat housing just to confirm that's not the problem.
I have been having the same problem on my 1982. A good friend suggested that the sending unit for the gauge maybe bad. This makes since to me, because if it was running as hot as the gauge reads I should be spewing fluid all over the place. I am going to replace the thermostat as well. I had to bleed my radiator multiple times to get all the air out. I am not sure were the air is getting in, but I replaced the filler cap just incase.
Try just filling it up first. If the water is low, the needle will swing way right then after a few minutes it will fall back to "normal" then slowly swing back up to hot. (Please don't ask how I know this for sure. I just do.)
Make sure you have a thermostat. My rad. was cool but the car was getting warm and turned out no therm.
FYI, the fans are turned on/off by a switch in the bottom of the radiator whereas the temp gauge gets it's signal from a sensor in the engine compartment near the thermostat. So, if your thermostat is stuck closed, the engine could overheat as indicated on the gauge, yet the radiator stays cool as no hot water is flowing from the engine to the radiator due to the closed thermostat so the fans would not come on. Or, if the water pump is shot, that too would prevent any water flow from the engine to the radiator. So, your problem does sound like either the thermostat or water pump to me.
Water pump can be an easy check,hows the heater is it staying warm,hot with the engine runing,even if the stats stuck closed there should always be a heater matrix flow,(turned to hot)depending on how its been flushed during coolant service,if its stuck closed theres your cooling system the heater system,thus overheat,dont jump at the head gaskets even though it may be the problem,stat,water pump,rad,hose and water pipe and a few castings,its all there is,never remove cyclinder heads unless you've done all the simple checks first,pump can be done quite easy,heaters cold find out why no circulation,then stat,rad,then its getting expensive,change the stat when you do a major,its a big money beautiful engine and a stats only a few £,$, there are chemical and other tests good shops can test for combustion gases in the cooling system,dont drive it,if its an electronic or cable type heater valve just check it is opening manualy, cheers Dale.
I propose you change your thermostat, refill, and bleed the system. Then see what you got. Bleeding is best done with a "pressure tester" consiting of a hand-pump connected to the system at the coolant tank cap. Pump it a dozen times, remove the pump, check to see if coolant is low, refill and repeat. Do this until you see coolant come out at the radiator bleed, close off the bleed screw. Continue until you see coolant come out at the thernostat housing bleed screw, close off the screw; and you are done. Your engine never has to come on. IF that does not work then we'll look at water pump and radiator blockagge.
I have to 2nd jwise. I had the same issue when the system was only about 1 quart low. Adding fluid solved the problem. Still, not a car I want to get stuck in a summer traffic jam - dont think it would make it without serious over heating.
These are also similar to the symptoms you get from air in the system. Air pockets tend to lead to a (relatively) quick rise on the temp gauge, followed by a return to normal, repeating every few minutes (intermittant "hot flashes"). The pressure bleed described by Mitchell (yelcab) cleared it right up, without needing multiple bleeds. One thing, though: Make sure you set the heater control(s) to full open (heat), so you purge all the air out of the heater cores, too. Otherwise, once you start up, that air will get back into the system. Forgetting to bleed the heater cores seems to be the most common mistake in the automotive service world -- even the television "how-to" shows forget this one.
Not needed on most cars. On "normal" cars, coolant always flows thru the heater core. Interior temp is controlled by varying the amount of air that goes thru the core. Old (say before the '60s) American cars used to have water control valves in their heater systems, but they were a constant source of problems.
I guess I've never owned a "normal" car, then. A quick check of the 328 parts catalogue shows electric valves on the coolent flow to the heater cores, all my Alfas had heater coolent valves, and I haven't owned an American car built since the late '60s. I haven't gotten that deeply into the shop manual on the EVO to tell on that one, yet (it's less than a year old). But the "temp" control on that one drives a pretty stiff cable. (I hear the new EVO-MR will have upgraded climate control.) Presumably, the QV also has coolent valves for the heater cores too, but they may be cable driven rather than electrically controlled as in the 328.
The heater system is always the first point of call when bleeding any automotive cooling system,because its higher up than the engine heat exchanger, cheers Dale.
I changed my sending unit this morning and bled for air pockets again. It has solved the problem so far. Yesterday I drove it and before I got 3 miles away from home it was in the danger zone, after this mornings work I drove it a good 20 miles or so and it only reached about 90c degrees. We checked and the thermostat is opening at the correct temp (according to my manual), the fans are coming on at the correct temp as well.
Doesn't have heater coolent valves, or doesn't use cables to control them? (I'd already mentioned that the 328 uses electric controls for the heater valves.)
