So, at lunch today I happened to look at my temperature gauge and it was at the half way point and climbing while I was at a red light. Light turns green and I start driving and the temperature goes back down to just above where it normally is. This continues to be the case as I drive back to the plant. Once I get to the plant I put it in park just to see how high the gauge would climb. It got to about the 3/4 mark and then quickly went back down to around half. I'm kinda puzzled by it. One would say thermostat, but they usually stick open. I looked underneath and didn't see any coolant leaking. Of course I couldn't check my fluid levels as the vehicle was hot. I will do that before I leave today. Possible clogged radiator?? I'm not sure. Any thoughts as to what else it might be?
Does it have an electric cooling fan? It has probably stopped working. When you start moving, you get forced cooling air and the temp drops. If it were the radiator, the temp would not come down when you stopped, same with the thermostat. 98% sure it's the cooling fan or a broken belt depending on your configuration. Of course it may just be going a little higher because it is summer time and you are running the AC and the engine is working harder than normal.
Just low on fluids, once your moving you get added air flow through the radiator and it cools down accordingly.
The water pump is driven by the timing chain, so I'm pretty sure that is not it. If it's low on fluids then I have a leak somewhere. I'm pretty sure my cooling fans kicked on when I had it in park. Thats what is was trying to see when I let it idle in park. Something happened to cool it off because it went from 3/4 to half pretty quickly, but I figured they would have kicked on prior to getting that hot.
I'd run with Occam's Razor on this one and just check the fluid levels before worrying too much about the other possibilities at this point. Also, it's normal for the heat to go up a bit when idling. And the temp. should go up after you turn off the vehicle. I had an old Lincoln with a 400 (or 460?) engine that had the right coolant level and no other cooling component issues; that still would start to overheat while sitting in Chicagoland traffic jams. I'd have to run the heater to help it cool down. Great memories... sitting in locked up traffic with the windows down and the heater on. At least it had a good radio.
Weird. Went out to my car and popped the hood. Screwed the cap off of the little reservoir and had a lot of pressure. That tells me the water pump works, but it was bone dry. Screwed the cap back on and drove it home. Temp gauge stayed below half. Let it idle in my driveway for over 5 min with the AC on and the needle never moved. Still need to add fluids and find my leak, but I thougt it was weird that it ran just fine.
Could the return line from the reservoir be plugged up? May be an issue in the reservoir part of the system causing the loss of fluid. Systems vents the excess when hot but can't recover it when it cools down? I wonder if there should be any pressure in the reservoir. I thought the vented freely.
I had the exact same problem last week. Was just my radiator fluid level. Hope that is the case with yours
I just had the same issue on my car at times the the water temperature will shoot up and then the water was overflowing from the reservoir. It had me puzzle because it would not do it on a daily basis I checked the fan and check water fluids the fan would come on and the water label was fine... I changed the thermostat and fixed the problem. The thermostat was sticking.
ok ,well for my 2 cents worth, if the radiator were clogged it would heat up while driving as coolant flow would be restricted. you didnt mention what vehicle and engine combomation you have. If the level is low and the tank was empty then i would top off the fluid making sure the mix is right . equal water and coolant then pressure test the system to look for any leaks. run the vehicle to ensure the coolant fans are operating with the a/c on, otherwise they should cut on at around 228 to 235 degrees. if the t=stat is esay to get to and the vehicle has some mileage then changing that is a good idea to change it and flush the system. the prestone flush is about the best one to get from the parts stores. i see alot this in the summer . hope it helps I am a GM service tech at a cadillac gmc ,buick dealership in tallahassee.
Just add some antifreeze. Prolly got a water pump leaking out the piss hole. Any time you turn the ac on the electric fan automatically comes on that's why the temp held steady when you did it. Why didn't you add some fluid when you seen it was "bone dry" ? And the timing chain driving the water pump? Lol Sent from my iPhone using Tapatalk
I didn't add fluid because I normally don't drive around with supplies from an auto parts store in my trunk. I could have tried to muster up enough spit to fill the surge tank, but time was limited. Sorry about the timing chain, I should have said timing belt. Any who, I just needed a flush and new coolant. All is good in the hood.
Glad it wasn't the fan as I said... There is another way to fill up the radiator by the way. Did you ever see "Red Dawn?"
