Your 91 integra when idleing will reach operating temp and blow hot air but when driving down the road it will drop in temp and not blow hot air and you have installed a new thermostat correctly help?

The year, make, model and engine info would help. Running todays cars without a thermostat may trip the check engine light to come on. The engine needs to reach and maintain normal operating temperature to run correctly. ...

the engine will take longer to get to normal operating temp. and the water temp could fluctuate while driving ...

Could be,Low on coolant. Cooling fan or fans not operating correctly. Coolant circulation restricted (blockage inside radiator). Sticky or stuck thermostat. Air circulation through radiator restricted (blockage outside radiator). ...

If the temperature gauge is reading below normal operating temp after driving a little while it may be that your thermostat is stuck open. I replaced my thermostat and it fixed mine. ...

do you have the right thermostat installed if so is it installed the right way ...

Sounds like it could be a bad thermostat - not closing to allow engine to heat to normal operating temperature ...

Thermostat is stuck open Thermostat is stuck open

head gaskets they all do it i have two 99 sts with the same problem cost about 2500 to fix correctly. ...

Driving or operating a watercraft under the influence can impact your drivers license. ...

If the thermostat in a vehicle sticks open the engine will not reach proper operating temperature. The open thermostat will prevent the car's heater from giving much or any heat during cold winter driving and will also cause the engine to use more fuel than normal. ...

There is none, who ever told you that lied. The thermostat is located in front of your driving wheel, on the dash board. ...

your thermostat in the cooling system is probably stuck open, you will need to replace your thermostat ...

If this happened immediately after changing the thermostat, then the most likely problem is the thermostat was installed backwards. The spring side of the thermostat faces the engine. It's the spring that is reacting to the coolant temperature and driving the valve to open/close. When the thermostat cannot open, that prevents any coolant from ever getting to the heater core. Thus, you shiver a lot! Pop it out, flip it over and you should be all sorts of warm and cozy. See "Related Questions" below...

This means driving under the influence of alcohol and/or driving under the influence of drugs. ...

Change your thermostat!

the squeeling noise is from the fan belt either the belt needs renewing, or the a/c compressor clutch is not operating correctly ...

If this happened immediately after changing the thermostat, then the most likely problem is the thermostat was installed backwards. The spring side of the thermostat faces the engine. It's the spring that is reacting to the coolant temperature and driving the valve to open/close. When the thermostat cannot open, that prevents any coolant from ever getting to the heater core. Thus, you shiver a lot! Pop it out, flip it over and you should be all sorts of warm and cozy. ...

You did not state whether you had this problem already before you did the work or if it suddenly started happening after. If it just started overheating after you did this, but was running fine before, the first place I would start is with the thermostat. I have bought a few over the years, that were defective right out of the box... that's why I test them all before I install them now. First, take the water neck off and make...

it might have a sticking thermostat.

I would suspect the plug wires have been installed incorrectly. I will list a link. Go there and check to see if you have the plug wires correctly installed according to the firing order. ...

you need a new thermostat

If your doing a lot of city driving you should get it fixed... the thermostat tells the cars computer when to turn on the fan which provides more the 50% of your engine's cooling in city driving! ...

"They" do not cause any engine operation they are only a sensor. If they are faulty they will give a false signal to the main ECU. The engine will still operate safely until they are repaired. ...

It depends on the setpoint of the thermostat.

OWI, or "operating while intoxicated", is another term for drunk driving.