Hello All, 1993 Honda Civic DX 16 valve 1.5 4 cyl 5 speed

First let me say I have read all the advice I could find on here and most of the information is pretty spot on. However nothing really addresses my issue exactly so I'll lay it out.

early 2005: I have a 1993 Civic owned since 1998, ECM dies, replaced with what turns out to be wrong model, I have 5 speed and ECM is for automatic. Car idles high at start and idles up & down when not moving (Less in summer worse in winter). Test the IACV and clean Thottle etc....Bupkis, Nada..... Do nothing and drive for 2 years or so. ($100.00 do myself)

mid 2006: Car starts over heating, Radiator the culprit, Replace that with new thermostat. $(70.00 do myself)

late 2006: Heads DONE FOR!!!, Have Machined, reassembled & New Timing Belt ($900.00 shop performed)

mid 2007: Replace Both control arms and tie rods, and tires ($600 total.. New Ebay Parts, shop performed work and tires)

Early 2008: Replace ECM with right model (after tracking down that issue).. reset computer & start car.. runs perfect no more high idle no more up & down idle, and radiator fan works again (Cost Nothing...Ebay ECM $50.00, sold my old one for $50.00)

Mid 2008: Blow a Radiator hose, Replace ( $20.00 do myself)

Late 2008: New Plugs, Wires & Brand New Distributor ($400.00 Shop Preformed)

Around this Time : Car Overheating/ Running Hot Randomly, ... Replace Radiator Cap $20.00 Kind of helps, boils over into overflow and eventually flows back into radiator after cool down, Did not do this before new Cap, had to manually pour the overflow back into the radiator .

Loses coolant randomly must refill randomly

Early 2009: New Pipe from Catalytic to Muffler ($60.00 Ghetto shop Performed) new muffler ( $70.00 Ebay Part Self installed) Gets me to work and school. I am a hermit so don't drive anywhere else...still running hot boiling over

Just last month or so: Car starts running all the way hot, have to replace coolant everyday, will drive to school and back with temp starting to get hot by destination.

Last Week: New Water Pump, New Timing Belt, New Oil Pan (Stripped Drain Plug) & Oil Change, New Air & Fuel Filter, New ECT Switch (under Distributor) and New Shifter Bushings ($500.00 Craigslist Mechanic & My parts) Craigslist Rules!!!!!

Well Almost... The car is running Hotter than ever now, wont drive 1 block before running hot, then overheating if driven any longer, boiling over into overflow, and empties completely back into radiator, light steam and water drip from tailpipe, Steaming from the overflow lid..... Sweet Smell(Not New)....

The car is also Idling High again at start and up and down when not driving, and the radiator fan only works if you jump the the coolant fan relay plug.

I am assuming it is my Coolant Relay Fuse, My IACV, and a blown head....

I'm looking at a re-manned head on ebay (since i already machined mine once and likely damaged it form all the overheated driving)... and a Brand new IACV... I'm thinking a pressure test and a new thermostat and radiator might also not be a bad Idea since they are cheap and i can do myself.

My question is how can I be sure it is not a bad block or something else entirely.
Before anyone says "just get a new car" .. We have had this car for 11 Years and it is my wife's first car from high school so she loves it and it is quite sentimental. (we had tons of hot teenage times in that car) The car made it through High School, College, and Grad School.. PLEASE HELP!!!

 

The switch that controls the radiator fan is on the thermostat housing, not the head. Unplug it and with the relay plugged in, jumper the pins in the plug. Fan should run now all the time the key is on. Test drive like that and make sure there is no overheating. If it doesn't overheat, replace the switch on the thermostat housing.

Continuing to drive while overheated is never good...

 

you can do a compression test, also i suggest replacing the thermostat again since its been 2 yrs, jump the fans and see if that helps, now for the idle, its a fitv its designed to open and let your motor rev a little higher than normal when you first start your car then when it reaches temp it closes and the idle goes down.

 

To adjust the FITV (on the bottom of throttle body) take it off, clean all parts with brake cleaner and screw the white piece all the way in and then back it out 2-3 revolutions. Did you use a new head gasket when you had the head machined?

 

OK... Thanks to all of you.

1. I jumped the pins on the plug on thermostat and the fan runs. Drove half a mile...Car still overheats.

2. I jumped the relay plug, Fan Runs, drove around block... Car Overheats.

3. Car takes longer to overheat just parked idling, (Have not timed it)

---Noticed these 2 issues.. the heat does not work, no hot air. and the top radiator hose was hot, but bottom hose was cold after drive and overheat test. Car only on for 20-30 mins total.

Going to now clean the FITV, when engine cools, see if that fixes idle.

PS. Yes I used all new gasket set kit with head re-machine in 06.,

What will a compression test tell me and is it different than a pressure test.

 

Is the radiator staying full? Heat not working usually means the engine is not completely full of coolant. Start with it cold and run with the radiator cap off, and add more as needed to keep it completely full. Then put the cap on before it gets too hot.

If running with the cap off, a lot of bubbles and gas come out when you rev the engine up, the head gasket is probably blown. That will force water out of the radiator and cause overheating.

Overheating along with the top hose hot and bottom hose cold means there is a major lack of coolant, the radiator is internally clogged, or the thermostat is not opening.

I would not worry about the idle at this point until the overheating has been resolved.

 

Did you try to do a bypass on the radiator fan? I Or is it working properly at the right temp? If its not working at the right temp i suggest try bypassing it.

To check if your head has problems open radiator cap turn engine on. If bubb;es coming up the radiator mouth then your head is warped.

 

i've experienced a similar problem with an accord (not mine) that if you use an aftermarket thermostat, it will not open properly if at all, the car overheated at idle and while driving and the fan came on normally, after replacing the new aftermarket thermostat with a new OEM one, the problem went away completely.

 

sounds to me like your radiator is clogged or the thermostat is bad or both.

 

So what I'm gathering is...

1. Flush Radiator check for blockage - replace radiator and cap if needed
   
2. Test Thermostat / Put in OEM Thermostat
   
3. Compression Test
   
4. Check for Blown heads by various methods suggested
   
5. Replace head and all new gasket set.... if needed
   
6. Then clean and test both the IACV and FITV - replace as needed
   
7. Then figure out why fan does not kick on. Already jumped the 2 spots, hook up toggle switch if needed

Does this sound like a good game plan.