1999 Honda Civic LX 1.6 OVERHEATING ISSUE

Radiator might be clogged. (at any speed) or water pump failing.

Yes its at any speed and how can you tell if its the water pump??

seen water pump impellers wear off all the fins and that would do it

I have a 98, had a similar issue. Replaced the radiator myself, pretty easy. Probably should check your water pump fuse. Your pump could be bad as well.

You should take it to an autozone and see if it throws any error codes on their computer.

Squeeze the hoses ...and when you release em ...you should feel the flow. (water pump test)

It may be your fan switch. [link to honda-tech.com]

Yes...make sure the fan starts when engine hot.

But that wouldnt overheat at high speeds.

Yes - do a flow test. Drain system, remove lower hose from radiator and flood with garden hose through radiator fill hole. Should flow fast unless there is core blockage. If flow looks OK then check water pump.

Wow, we got some pinche mechanics in here huh?

I had some problem i change radiator but it still over heats even changed the waterpump and its still messed up .. i dont know if i have a defective new radiator but i might have to return it

thermostat?

I'd change it out just in case, not expensive.

There will be play in your fan. Push and pull on the blades to test. PS make sure the motors off.

I Checked the hoses already and they are fine when it comes to the pressure and hearing the rad fluid moving and i hooked the rad fan strait to the battery the heater core seems fine and I took the Thermostat out checked all fuses and switched relays and still overheating and thanks to all for the advice

This is not the Forum site for this. Go to
www.Honda-tech.com. As for your problem, could be a number of things, The thermostat could not be opening up, is your fan turning on, is your radiator working properly. The reason it runs hotter at idle is while you are moving the air cools the engine. When u blast the heat it takes some of the heat outa the engine bay, its a trick you do when your car is overheating. Go to Honda-tech you will have a lot more help than here. (and it could be your water pump, most fins on the honda's are metal and dont wear off though.

Last Edited by Mindgamez on 09/07/2011 01:08 PM

throw a code reader on it. it may be your on-board computer is fubar. and check the wiring connection on the thermostat, make sure the contact points are clean and well seated. does your fan come on @ idle rpm? if not, check the fuse and the switch. what kind of water pump is on those civics? is it in the block and cam driven, is it electrical or mounted on the block and belt driven? if it's electrical, check the fuses and the switch. if it's belt driven, make sure the belt tension is right. if it's in the block and you're sure it's a bad pump, make an appointment with a mechanic.

first, do you have heat coming from the vents?

nvm didnt read clearly first time, just pressure check it at rad cap and see if it holds, if it doesnt, typically, you will see a leak that is causing a drop in pressure. for every 1lb of pressure exerted on a cooling system=250f hotter your coolant can go w/o boiling, the coolant will be allowed to get hotter than boiling, w/o boiling. So, if you have a leaking gasket/radiator/hose/whatever, it would make sense that it would cause a pressure drop which would then cause it to overheat and lose cooling system pressure. The water pump, though, could be out, since that is where the pressure comes from, and heat.

Check ur radiator cap it to can cause your car to over heat.

check theres actually water in it. it probably rusted a hole through and all leaked out.

Also check the oil levels.

Probably a false flag operation to take away our rights. In fact, I think I've seen your water pump before acting in a MacGuyver episode.

I had a 98 Civic, water pump went bad, there's a little weep hole that will start leaking, check that. If it is that, might as well change your timing belt too while you're at it.

Taking out the thermostat doesn't prove anything.
Some cars will overheat without it.
It could just be a bad thermostat.

Replace it with a new one.
Begin there.
Thermostats are cheap.

Use only Honda Coolant(the fluorescent green).

Check your ooil dipstick if it is high with milky stuff llook under it whiile running foor leaks theses things can be difficult ta pinpoint.

replace the thermostat

It might not be fitted to your jap mobile
Some cars have some spring type resistors in. The fan feed so as to have a normal spin then when in over heat will spin faster

Check the fan operates at about 85 ish celcius

everything you described in your original post.

This too.

Make sure you call 911 ahead of time and have the ambulance close.