Idle too low on my 2000 honda civic.

Hello all,

I just bought a 2000 honda civic ex with 54k miles on it. The problem
is that the car once is warmed up, idles too low, almost at the 0rpm
line but probably around 200-300rpm, however the needle looks like its
all the way on zero. Once i accelerate, the engine shakes a bit and
then comes back to normal, but same thing happens again when i stop at
a stop light etc. Everything is stock. Any help would be appreciated

Thanks

Luke

 

Start by waiting overnight (until the engine is stone cold), then remove the
radiator cap and top off the radiator. Fill the reservoir to at least the
minimum line. Run the car until it's at Normal Operating Temperature, then
add coolant ot the reservoir until it's at the max. line. Lastly, purge the
cooling system of air.

Certain engine control components, including idle control, have coolant
passing through them. If there's an air pocket, they aren't being properly
cooled, and mis-idle problems like yours can occur.

Very common.

 

wrote in

That's 500 rpm, not zero. The tach cannot read lower than 500 rpm.

Check cleanliness of throttle body. Check cleanliness of IAC (Idle Air
Control valve).

If IAC is sludged up, it will be unable to adjust the idle properly.

 

Where is that IAC located? What does it look like?

 

Right behind the throttle body about where the throttle plate is. It sort
of looks like a cylinder. It has two tiny coolant hoses connected to its
underside, and one electrical connector.

You should pull off the air tube to the throttle body. This will expose the
throttle plate and the intake port for the IAC. If the thing is oily and
gungy, you'll know right away.

 

Checked my 94 VX, & had the same problem. A ? about purgeing the
system. Just keep topping off the reservoir, or is there something else
to do?

Thanks

Mike

 

Yes, there are a few more steps. Your owner's manual has this procedure.
Alternatively, use the following:

1.
Mix a solution of 50% ethylene glycol (designed for use in aluminum engines)
and 50% distilled water. With the engine cold, remove the radiator cap and
fill the radiator all the way to the filler mouth.

2.
Loosen the cooling system bleed bolt to purge air from the system. (If you
don't know what this is, ask.) When coolant flows out of the bleed port,
close the bolt and refill the radiator with coolant up to the mouth.

3.
To purge any air trapped in other parts of the cooling system, leave the
radiator cap OFF, set the heater control (inside the passenger compartment)
to Hot, start the engine, set it to fast idle and allow it to reach normal
operating temperatures BY LETTING THE FAN COME ON TWICE. This will probably
take at least 40 minutes, so have a magazine handy. Meanwhile, DO NOT
tighten the radiator cap and leave the heater control in the Hot position.
When the engine reaches normal operating temperatures, top off the radiator
and keep checking until the level stabilizes; then, refill the coolant
reservoir to the Full mark and make sure that the radiator cap is properly
tightened.

 

Thanks. I've noticed its better already. I'll use this procedure to
finish it off.