I recently picked up a completely stock 1989 Civic Hatchback with about 150k on the odometer. It has ran perfect for about a month and then I started noticing a high idle after starting it. I have just been giving it a little gas to get it to go back down, but sometimes it would start idling up & down after that. I never did anything about this.

Last night I ran it a little harder than I should have, and left it running outside right after for about 10 minutes. When I came out, antifreeze was boiling pouring out of reservoir cap, but nowhere else as far as I could tell. I picked up a thermostat at a parts store just in case but haven't begin to work on it yet.

I'm going to go get a manual for the car here shortly. What are some things I should check before I tear into it for no reason?

 

Belt has plenty tension on it, isn't squealing or anything either. I just let the car run a little while and the top hose is getting hot before anything else is so that means the thermostat is open. The engine is heating up in a normal amount of time also so I'm guessing it's not stuck open. I'm going to fill it back up with antifreeze and take it on another test drive to try to get the issue to repeat. Everything looks good now though, go figure.

 

Definately sounds like a thermostat. Thats your cheapest safest bet. If that doesn't do it, and you have no leaks anywhere else and the radiator fins are not pinched but wouldnt cause overflow otherwise, the only thing moving your antifreeze is your water pump, but if it seized you would know.

 

The part store thermostats are really no comparison to the OEM thermostat quality.
Take it back and get one from Honda if you can.

 

Thanks. I will check on an OEM thermostat at the dealership tomorrow. It's like $30 shipped on Majestic. I thought I ruled out thermostat according the manual, but I will try it anyway. I'm going to check the fan too after I get some jumper wires from Wal-Mart. Stupid Autozone don't have any.

 

Today I finally installed the OEM thermostat successfully. The old one WAS stuck open. Now, my fan still won't start. I'm having trouble figuring out how to go about troubleshooting this. The blade spins free, all the connections seem to be made also. I can't find any diagrams showing what switches need to be looked at for the d15b2 engine with this issue.

 

Fan is pretty easy

Disconnect the fan connector and hook it direct to battery with some spare wire. If it spins, it's good. If it doesn't then replace the fan.

Check fuses - don't just look at them get a tester and electrically make sure they are good.

On the back of the block by the oil filter there is a large black rubber plug. It has two indivisible connectors under it. Those hook up to the thermo switch that tells the fan to turn on. One of the wires goes directly to ground at the thermostat housing. The other wife runs to the fan relay. When the thermoswitch gets hot, it closes the ground circuit to the relay.
Disconnect the two wires from the thermo switch and connect them directly together. Turn the ignition ON (engine doesn't need to be started) and the fan should come on. If it does, then your thermoswitch should be replaced.
If the fan does NOT come on, then hook the wires to a known good ground. If the fan now comes on, then repair or replace the wire that goes to the thermostat housing.

if the fan still doesn't come on, then troubleshoot the fan relay.

 

Fan didn't come on.

http://estore.honda.com/honda/parts/...&b=B++0502&dl=

Do I need the fan shroud or fan comp, or both? Should I go with OEM or after market?

 

My dealership here in town wants to charge me $242.12 for just the motor. Should I be looking into used parts or aftermarket instead?

 

Check a junkyard. It should be under $60 for the fan with shroud.
You really only need the motor though and just swap it out.

 

Hondas like ours are rare or nonexistent in junk yards around here. Could I use a fan motor from a newer model Civic or any other model?

 

You can buy things from junkyards on the internet.
I'm not sure about the newer model fans.

Also, try posting in the FS/WTB thread up at the top of the page.