Michael Haldt

so I have a 95 civic DX sedan 5 speed


had a surging idle issue, did the little idle learn trick and it fixed it. But now after I replaced the radiator and fan with an aftermarket dual core rad and "racing" fan the surge is back.


I pulled the IACV cleaned it and put it back on. Pulled the FITV cleaned it put it back on before replacing the radiator. didn't do anything until I relearned the ECU.


if I take the intake off and plug anyone of the holes the idle surge goes away


what am I missing, what next,

ezone

Low coolant level can do it, did you get all the air pockets thoroughly burped out?

Michael Haldt

What is the best way do that? I've never heard of doing it

ezone

Check this thread, 2nd post has some of it

https://www.civicforums.com/forums/36-mechanical-problems-vehicle-issues-fix-forum/340759-overheating-mysterious-coolant-loss-common-causes-reference.html

The 5th gen cars may trap a large amount of air in the heater system and may need more intrusive work to get the air purged manually if it doesn't with the usual methods.
If there is air trapped in the heater system, you probably won't have good HOT heater temperature output at idle.

Michael Haldt

Thank you,

I did that and I pulled the thermostat off and tested to see if it opened, which it it did open, but the surge is still there.

Also I put a new fan switch on the car cause my fan would never turn on, and I figured it was a cheap part might as well replace it. The car got real hot and the fan never turned on, I put a paper clip in the connector so the fan would cool the engine cause it got so hot. The relay is good otherwise the paperclip would not have turned on the fan. So why would a brand new switch not tell the fan to turn on?

And doesn't blow hot air even when the engine terribly hot, what do I do there?

Side note: when the car really hot the top hose look like it was about to burst

ezone

Air pockets that are trapped within the cooling system can disrupt proper flow/circulation of the liquid (coolant).

Each of your listed issues could be caused by this.

The hose routing for the heater system might cause air to become trapped, that air may not be able to find its way to the radiator for typical burping.

Michael Haldt

thanks ezone for the help


idle issue is gone, I just fabricated a plate for the FITV so the coolant runs through but no air, I know later ill replace it.


heater sill blows cold, flushed the whole system but still nothing, there is hot water going to the core but sill cold coming out of it. I think im coming to the assumption that the water pump needs to be replaced. does anyone know how to make sure that is my problem? from what I can tell there is no water coming from the weep hole, don't know if there is play in the pully. is there anyway to make sure that's the problem without taking that whole side of the engine off.

ezone

What exactly did you do here?

What did you do to get trapped air worked out of the heater hoses?

Have you made sure the heaters water valve lever moves to the open and closed positions, and the guts of the water valve is actually wide open in the full heat position?

I think you would probably have far bigger overheating problems if the pump impeller were wiped out.