The upper radiator hose gets hot do to the fact the coolant has started to circulate.
When you start the engine, the thermostat is closed. After the coolant warms up the thermostat begins to open up allowing coolant to flow thru the raditor. When first started the temp will go a little past what the thermostat is set to open at. After the water begins to flow thru the radiator, the temp will fall to whatever the thermostat is set at. The thermostat holds the coolant in the engine until it warms up. As soon as the engine is warm, the thermostat opens allowing cold coolant outside the engine to mix with warm coolant. The temp drops, the thermostat closes again, until all the coolant is warm.
Try replacing the coolant temp sensor, the one next to the thermostat housing.
Coolant level low? Check when cold Cooling fan not working? Thermostat not opening? Dirty or clogged radiator? Bad radiator Cap? Water pump bad?
I asked my mechanic about that and he said it was under the intake manifold. about 400 dollars to repair. On the other hand I was low on coolant, so I added coolant and it started warming up faster and the temperature gauge wasn't so high either. So I didn't have to repace thermostat. good luck I asked my mechanic about that and he said it was under the intake manifold. about 400 dollars to repair. On the other hand I was low on coolant, so I added coolant and it started warming up faster and the temperature gauge wasn't so high either. So I didn't have to repace thermostat. good luck
All sorts of thing can.. Low oil, low coolant, blocked radiator, stuck thermostat, running too lean on fuel... If it just suddenly started to do it and the levels are ok then check the thermostat.
Low coolant level? Thermostat not opening? Water pump not circulating coolant? Heater core airbound? Heater core plugged or restricted?
Does the computer also say low coolant. On start-up mine did that so I'm pretty sure it does that to make sure you check that the coolant level is ok. If coolant level is good then the thermostat is probably stuck open.
the thermostat is probably not functioning properly...replace thermostat and see if the situation is resolved. Easy cheap fix. Check your coolant level before replacing the t-stat. You may just be low on coolant.
Place a pan under the drain valve on the radiator (back side of the radiator, right side) Reach up and open the valve letting the coolant out. (It is meant to be turned by hand, but you might need a pliers) After the coolant has started draining open the radiator cap to allow air into the radiator. Go back to the engine and open the thermostat cap (Large cap that looks like a radiator cap, has a two step turn - push and turn again removal). Remove the thermostat located under the cap by grabbing it, turning it to break the seal and pulling it up. To fill - close the drain valve on the radiator. Leave the radiator cap off and start filling by pouring the coolant into the (still open) thermostat cap. Note - the thermostat needs to be still removed. Have an assistant watch at the radiator and when it gets full he needs to quickly put the radiator cap back on. Then continue to fill at the thermostat cap till the engine is full. Now start the car and let the coolant circulate, refilling at the thermostat cap when the coolant has dropped. After the car has warmed up, and all of the coolant bubbles have come out, fill the coolant to the top of the thermostat cap housing, replace the thermostat and cap and fill the reserve tank to the warm mark.
Low coolant? Radiator plugged or restricted? Thermostat not opening? Water pump not circulating coolant? Defective radiator cap? Radiator hoses collapsing under pressure? Cooling fan not working? Cooling system air bound?
If coolant leaks onto an engine it will cause no damage unless it leaks onto the alternator or into a wire harness connector of some sort. It is best to clean up leaked coolant as much as possible. It will smell a little when the motor is started. Leaked coolant on the ground is a danger to animals and children as it has a sweet smell but is very toxic.
If your 1997 Subaru Legacy is the same as My RS-B Twin Turbo?, the Radiator and Overflow bottle have to come out and the Thermostat is at the front of the Engine, down the bottom-just to the right of centre, (Thermostat is inside the bottom radiator hose), - My Thermostat just twisted/pulled out, let all old coolant flush out-put New Thermostat in its place, Radiator and Overflow bottle were put back in and radiator topped up with fresh coolant and water, Overflow was filled to second line as it should be, car was started with heater on full for 5 minutes to disperse any air in water - (note) after adding fresh coolant, add water in Radiator till it can't take anymore-to show its filled properly.
Have you checked the computer codes? If so, what do they say?
I added some coolant to bring it up to the add line...vehicle hadn't been started all day. I will take it out tomorrow and see if it continues to do this. I may need to get a new thermostat. Check coolant level May be a defective radiator cap Radiator hoses may be collapsing under load Gauge may be defective and/or also below answer That sounds like a sticking thermostat.
fualty gaskett, or installed incorrctly most likely you have coolant in your combustion chamber, check your oil for coolant.
ON the coolant resevoir, look for the hose that runs to a tubular metal connection, it is a smaller hose at the top, make sure coolant flows out when the car is started, willing to bet it is blocked from the point where it connects to the heater core unit. I had the same problem. car works fine now
It could be low on anti-freeze/coolant. The coolant ratio could be off (especially if there is a leak and you have been adding water not 50/50). It could be the thermostat. It could be the water pump. It could be a plugged radiator or heater core. Begin with the least expensive and easiest and diagnose deeper until you find the problem.
Assuming fluid is not lost, and thermostat is not sticking, and water pump is working, and radiator not blocked, must be electric fan not cutting in. I think its switched on by a sensor on the block. Check cut in of electric fan. IF thats working, must be blocked or ineffective radiator.
yes, because once the coolant started to steam it would seep out.
I don't have an answer to this question but want to add to it so hope this is okay, this is a problem with Buicks in General and should have been recalled. The window motors on my 1997 Buick Skylark (purchased in Jan of 2000) started going out in March of 2000
Possible new thermostat is bad and not opening. Is the lower radiator hose soft? Had a Ford pickup one time that would run hot when driven over 55MPH. Finally figured out the lower radiator hose was colapsing with high engine RPM from the suction of the water pump reducing coolant water circulation. Hope this info helps cure someones problem.
can the gasket go bad behind the water pump houseing
You should add coolant with the engine off and cool, top off the radiator and fill the coolant reservoir to the cool or cold level. When the system is hot or running it will be pressurized and will be dangerous to open. You can however add coolant to the overflow reservoir at any time.
Faulty thermostats can manifest themselvs in several ways. Some stick open, some stick closed and some stick in one position for a while then suddenly open or close. The ones that stick open will never allow the engine to completely warm up and you will get cold or cool air coming from the heater. The ones that stick closed will cause the engine to warm normally but then the temprature continues to climb and you can loose coolant and possibly harm the engine. The ones that stick for a while are interesting because the vehicle will run cold then turn warm quite rapidly or more likely the thermostat will stick closed and not open until the vehicle is quite warm and possibly you have started to loose coolant. In any case, the easiest way to detect a bad thermostat is to replace it. If the problem goes away, it was the thermostat. If you REALLY need to know if the thermostat is bad, remove it from the vehicle, put it in a pan of water and bring the water to a boil on the stove. Watch the thermostat. If it opens smoothly when the water gets to the designated temprature then the thermostat is ok. If the thermostat opens suddenly, fails to open or is open when you remove it from the vehicle, the thermostat has failed.