Is it bad to remove the thermostat?

Answer 1

yes, it's bad to remove the thermostat! Unlike in the 'old days' it's very bad to remove your thermostat from a modern vehicle. As well as regulating engine temp. the thermostat provides flow restriction without which coolant often will not flow uphill to your heater core (which is very often the highest point in your cooling system.) Another important benefit of flow restriction is that it prevents errosion. Very often, shortly after removing the thermostat, radiators develop leaks requiring radiator replacement because the tops of the tubes (in the top tank) have erroded away. Leaving the thermostat out entirely also reduces the pressure that the coolant in the engine develops. This decreases the temperature at which the coolant boils and can cause bubbles of air in the coolant at the hottest places in the engine. These bubbles then act as a thermal insulator which makes those hot parts of the engine even hotter. But your temperature guage will still be showing 'normal' temperatures. If the engine runs hot in one particular area, it can damage the piston rings eventually causing the car to smoke, burn oil, and eventually cause total engine failure. I drive a little 89 Nissan Pulsar NX and it overheats like MAD. Had to replace the radiator because it was spraying out steam at one point in the middle of traffic.

Now with a new rad it still overheats and I constantly had to have the radiator fan going. I even went as far as to have a radiator fan switch installed in my dash.

A friend of mine recommended removing the thermostat during the summer because there was a big chance that it was actually 'causing' the problem. Well I had it removed and god am I happy! It doesn't overheat anymore, been driving it for a year now and it's alot better.

Then again this is just a fix for MY car, this wont work for everyones' car.

both answers are good . i used to have a na fairlane stretch limo that over heated in summer due to the twin air conditioners and Ford engines being heat generators. what i did was get a lower temperature opening thermostat which sorted the problem as without the thermostat completely it ran rich in winter as the computer never kicked the choke out.Then in summer it still ran hot as the flow was too fast.