My 94 accord yesterday afternoon the temp gauge went up to half way. Its normal running temp is about 5/16" below half way. The engine cooling fan seems to be working properly and there are no visible leaks anywhere. I checked the water in the radiator this morning and added maybe a pint to top it off. I checked the oil and it is just on the tip of the dipstick. I immediatley filled the oil to the correct level. Can the engine being low on oil make the temp gauge to read high? I replaced the thermostat several years ago and although most people say first thing is its the thermostat, really how often does a thermostat go bad. To be honest Ive never seen one go bad.

 

As long as you are getting oil to the bearings the temp should not go up. And I am guessing that no oil warning light came on. If you had to add a pint to the radiator (and not the overflow bottle) then that is the place to look. Somewhere water is leaking out of he cooling system.

 

I did a pressure test on it. Pumped it up to 16psi. The pressure bleeds off pretty quick but I don't see any leaks. I'm not sure if the adapter I was using is leaking or what. With as fast as it bleeds off I should see a leak somewhere. I don't think its a head gasket because the car runs great. Has me baffled.

 

Just took the car on a 15 mile ride and when I came back let it idle in the driveway in gear for 5 minutes. It ran normal temp the whole time. I think the adapter on the pressure tester I was using leaked. I could hear what sounded like bacon frying where the adapter was connected at. I think that is why it leaked down. Still don't know why it ran warmer than usual yesterday though. There has to be a reason.

 

Maybe you were heavy footed that day...

 

I found a tiny trickle leak where the upper radiator hose connects to the engine (between the aluminum piece the hose goes to and the engine). Is there a gasket that goes between the 2 pieces? It only trickles a little bit when first started and goes away as the engine warms up. Tried to tighten the 2 bolts that hold it on but they are already very tight. Also is a pint low on water in the radiator enough to make the gauge read a little higher than normal?