HELP: 1995 Civic Over Heating

Asking about my cousin's 1995 CIVIC DX (With A/C) Overheating and need to
know some things.

Given my limited knowledge, I checked with the engine at idle, after a cold
start, that the right most fan is not on. The left most fan (exclusively for
A/C) was also off. When I turn on the A/C, the left fan does come on.


QUESTIONS:

Generally, how should I help my cousin debug this problem of overheating?

Specifically:

(1) When does the normal engine fan (right most fan) come on?

(2) How can I check that the right most fan works?

(3) What role does the thermostat and temp/sensor play in the overheating
scenario?

(4) If the engine fan and temp/sensor work together, can a bad thermostat
cause overheating?


Thanks,

Gary

 

So in other words, the right (regular cooling) fan never turns on, even
with the AC on?

When at a certain temperature and when the AC is on.

A fuse for this fan exists, so check it first.

Look in the under the hood fusebox. You'll find two relays: one for the
radiator fan, one for the condensor fan. They are most likely the same
type. If they are indeed the same type, swap them. Start your car and
turn on your AC. If now the cooling fan runs and the condensor fan does
not, your problem is in the relay that you now swapped to the condensor
position. Replace it.

If nothing changes, your relays are most likely fine. Get a volt meter
and measure acorss the cooling fan with the AC on. You should see 12V.
If you don't, try putting one lead onto a good ground point and try
again. If you now see 12V, you have a bad ground connection to your
fan.
If you still don't see 12V, your problem may be in the wiring to the
relay, the relay contacts or the relay itset.
Locate the coil position on the relay, turn on the AC and measure the
voltage. You should see 12V. If you don't, one of the contacts goes to
a junction. That junction is most likely bad.

If you do see 12V on the relay, locate the contact position on the
relay. The common should have 12V on it. If so, short the contacts and
see if the fan turns on. If it does not, your problem is with the wire
going from the fan to the relay. If it does turn on, your relay or the
contacts to the relay must somehow be bad..

The car will overheat with it closed, but your fan not running is a
prime suspect.

yes, assuming the fan does turn on at some point.

Hope that helps you.
Remco

 

You can tell us EXACTLY WHEN the car overheats.

1) Idling in heavy traffic, cools off once you start moving again
2) At speed on the highway; cools off once you stop
3) Hot all the time
4) Other

Rad fan will not come on until the coolant temp exceeds 194F. About 5
minutes in heavy traffic on a hot day will do that.

More detail please. No detail, no help, no solution.

 

Thanks, you gave me a lot to chew on. Today I read a Honda repair manual at
Pep Boys. It said to feel the top hose and if its not hot then it could mean
a closed thermostat.

I checked the repair records and the thermostat has not been changed since
the car was new, and that's over 10 year of hot summers and tough winters.

 

The car overheats, just idling. This is with and without the A/C fan
running. Since I did not do the test personally, I do not yet know:

IF

(1) The main fan works?
(2) The thermostat's condition?
(3) The temp/sender is working or not?
(4) The Fan fuse condition?


I a;so went to the Honda dealer to buy a thermostat but parts was closed. I
talked to the clerk behind the service counter and he said its probably the
Head Casket (99 out of a 100 times is what he said) or the Water Pump.

While praying for the problem to be a fuse or thermostat or temp/sender, how
can I check to see if its the water pump or Head Gasket if the other things
seem to be fine.

Thanks,

Gary

 

lets hope not.

a compression test should be able to tell the gaskets status. waterpump?
hard to tell.

replace the t-stat
do a compression test
if it checks out ok, then do the water pump/timing belt.

 

I take it the fan does turn on then?

Agreed - I'd change it for problem prevention sake if it has been in
the car that long.

 

Plus, while this 10-year-old thermostat may work, it may not work optimally.

My 1991 Civic's thermostat worked fine for 13 years, but someone here
suggested replacing it for the reasons above. It's also cheap enough,
especially if one does it one's self, to warrant removal every ten years.
You could replace it and then that's one less thing (that was about due
anyway) to worry about as you troubleshoot. Or it might solve the problem.

Hey, listen, with your 95 Civic just idling on your driveway or your garage,
as much as 50 minutes may be necessary to get the radiator fan to come on.

I suggest replacing the thermostat, then purging the system of air, since
you will have opened it and likely lost some coolant. Use the manual. It
directs, among other things, that a proper purge requires idling long enough
so the rad fan comes on twice.

I am not kidding about how long it may take. I timed it last year with my 91
Civic. Some other folks confirmed that, just idling in the driveway or
(open) garage, it may take this long. Have a magazine.

I thought my fan wasn't working correctly, too, until I got this tip.

If you're doing this yourself, www.autozone.com has free repair guides,
specific to the 1995 Civic that tell how to. They duplicate Chilton's and
apparently often Helm's.

Good for you that you have repair records.

Buy only an OEM thermostat. It's worth the few extra bucks.

 

Is it possible to change the thermostat without having to drain the
radiator. Reason has to do with where the 1995 Honda Civic is currently
parked.

 

yes, but you will have some spillage and will need to refill accordingly.

 

I know the directions for 1984-1995 Civics say to "drain the cooling
system," but I did NOT do this last year. I think maybe someone here said I
could get away with NOT doing a full drain, thus.

I don't think I opened the petcock and drained even partially. But by not
even draining a little bit in advance, then as you disassemble to get the
thermostat out, some coolant definitely will come out. Have a pan or wide
bucker underneath where the thermostat is to collect it. Kinda messy, so
you might want to try the following to minimize the mess: Note the height of
the thermostat housing. One wants to try to drain to below it. Attempt to do
so by opening the radiator petcock (draining into a pan) and watching the
level via the radiator cap opening.

I don't think I had to add much coolant. I did goof by not doing a proper
re-fill and air purge the first time. You already have my warnings about
that: Wait at least 50 minutes for the fan to come on before deciding the
fan is broken in some way. (The outcome of having air in the system was
improper cooling of certain engine control components, causing an irregular
idle. This was fixed easily by doing a proper air purge of the cooling
system.)

Add the same coolant as that that came out. If you're not sure what coolant
it is, consider doing a full cooling system drain and fill, with maybe a
flush in between with water. It's not difficult. Refill using only Honda OEM
coolant or you can try Havoline orange Dexcool. Do not use green prestone.
(At least, that's my opinion.) If it's not premixed, use only distilled
water to dilute the anti-freeze.

 

Oops, let me clarify: Add the same BRAND of coolant, but new from a bottle,
as that that came out.

I wouldn't re-use the old coolant. OTOH, if you keep the bucket or pan you
use to collect it clean, it's probably not a big deal to do so.

 

Disconnect the connecter coming from the temp/sensor relay at the back
of the fan motor and go directly from the battery to the fan terminals
with a jumper set. If it turns it is good. If it starts to turn and
then stops or starts to turn when you tap the motor housing, generally
the brushes are worn out.

 

The best method is to partially drain from the radiator and reuse it. These
coolants can go 30K miles or 3-years. There's no need to dispose this
environmentally unfriendly substance unnecessarily.

 

If you see bubbles coming out of the filler neck even after you properly
bleed it then your engine will need a funeral service or servicing.

If the upper hose or lower hose isn't hot when it overheats then the
fan usually won't come on. You could pot boil the thermostat.

If it's not properly bled on some cars the fan will not come on because the
waterpump can't do its job. Of the many cars I've dealt with bleeding is
almost unique to each car, yet few will ask how to do it correctly.

 

Group, many thanks for all your help. Unfortunately, the conclusion to this
disaster was a corroded radiator and the multiple times the overheating
happened which caused the head gasket to go. It could not pass the leak
test. I was hoping for just the thermostat and ended up with the one step up
from the worst case scenario. That would have been a warped block.

QUESTION:

Is this normal for Hondas, or just the Civics? I am referring to the
robustness of the head gasket when over heating occurs.

 

hondas have an all-alloy block, so heat distortion is exaggerated, but
that's not unique to hondas. repetition will make the situation worse.
the real question however is how did it get to be repeatedly
overheated? fix that problem before blaming honda.