Civic EG

Over heating is something that I hear about a lot for these cars, and something that I experienced myself.

If your Temperatures are hot these here are some solutions:

1. Bleed your coolant system.
Airbubbles could be trapped in the system which can lead to overheating. With your engine cold, NOT WARM, remove the radiator cap (on radiator, not plastic overflow tank. Then start the car and let it warm up. Turn your heat on high. You may need to hold the throttle at 1500 RPM to get the engine hot enough. When it warms up, you will hear the thermostat click and your coolant will start flowing. Keep a container of mixed Coolant/Water and continue to top off the radiator when it gets low. This will fill in any air bubbles.

2. Check Thermostat. It may be stuck shut all the way or partially. This will cause overheating. Stuck all the way open will cause your engine to never warm up.

3. Check your Fan. If you are overheating in city driving or stop & go traffic, it may be your fan not coming on. Highway driving will push air through your radiator but you need the fan on in the city.

4. Old radiator. Some of the EG's came with a VERY thin radiator about 5/8" thick. I know for a fact that the dx comes with the 5/8" radiator. I replaced it with an EX radiator which is about 1.25" thick. It may just be time to upgrade. Over time build-up and deposits will clog up the channels of the radiator like McDonalda clogs your arteries. A symptom of this problem I had was the temp needle going slightly over 1/2 way on the highway and then going all the way up to HOT as soon as I got off the highway into the city.

5. Headgasket. A bad headgasket will cause overheating. Your car may not blow the obvious white smoke that is known to mean a blown headgasket. Check your coolant, if it is dirty, milky, or has any trace of oil in it, then it could be your headgasket.

6. Blocking flow. You cold have something like a bolt or nut blocking the flow of coolant. Maybe when you were working on the motor, something fell in to a coolant passage.

7. Water Pump. May need replaced.

Also when you add coolant to your civic, Add it to the radiator (only remove the cap when your engine is COLD) Adding it to the overflow tank does not mean it is going into your cooling system. The overflow tank is mainly for overflow as the coolant expands when hot and contracts when cold.

i have the same problem but a little differant. mine heats up when there is no coolant but that is a given. my problem is i have to fill up the coolant from time to time but there is no leak. where is the coolant going?

hatchiespank wrote:i have the same problem but a little differant. mine heats up when there is no coolant but that is a given. my problem is i have to fill up the coolant from time to time but there is no leak. where is the coolant going?

If I were you I'd drain the oil and look for coolant in there. Coolant doesnt just burn off.

i change the oil every 3k and i never see any coolant in it. any other ideas? it is a brand new radiator as well and so are the heater hoses.

give us some more info on your motor setup , how many miles, any mods? How often do you have to fill your coolant?

it is a stock d15z1 just a in take and i fill it up with the coolant resivor.

try filling your radiator instead when your engine is cool. also are you sure tere are no air bubbles in the coolant system?

how often/much are you having to fill the coolant?

I have the same problem my civic overheats at stops. I fill the radiator almost every other day. I checked the oil everything looks fine. I replaced the cooling fan switch but it doesn't seem to come on when it gets hot. There is no leak. This is a 95 honda civic ex this has been going on for about a year and a half any help.

maybe the fan needs replaced? If it was something engine related, your fan should still come on to try to cool it down.

So at least the fan is easier to replace than a waterpump or headgasket

live near any friends with EG's? just go over and trade fans for an hour or two. There's only 4 or 5 bolts to remove. If your civic doesn't overheat, then you'll know for sure it is the fan before you buy a new one.

Here's something to note. DO NOT USE a Mugen or SPOON radiator cap on a radiator with plastic end caps. The plastic will crack and you'll be spraying coolant.

Just run the power wire from the fan directly to the battery, if it spins its not the problem.

ChicagoMike wrote:Just run the power wire from the fan directly to the battery, if it spins its not the problem.

I like your idea better... much easier

buy a new thermostat i had your exact problem and turned out to be the problem

DJ NeX wrote:Here's something to note. DO NOT USE a Mugen or SPOON radiator cap on a radiator with plastic end caps. The plastic will crack and you'll be spraying coolant.

I do not understand this logic here. what does the cap do to cause the plastic to crack?


The Mugen and Spoon just changes the pressure in the system to a higher temp to allow the water to retain more heat before hitting boiling point. There should be no reason why it would cause the plastic to crack.

LowTEC-Derbo wrote:

DJ NeX wrote:Here's something to note. DO NOT USE a Mugen or SPOON radiator cap on a radiator with plastic end caps. The plastic will crack and you'll be spraying coolant.

I do not understand this logic here. what does the cap do to cause the plastic to crack?


The Mugen and Spoon just changes the pressure in the system to a higher temp to allow the water to retain more heat before hitting boiling point. There should be no reason why it would cause the plastic to crack.

The stock cap is 1.1 bar (or 15.9lbs)
The others are a 1.3 bar (18.8lbs)

Too much pressure.