Coolant Vanishing: '95 Civic EX 1.6 - Attn Tegger and Techs

When I had the oil changed in November, I was told they had to add
"quite a bit" of coolant to the reservoir. Since the car came from NM,
with a spotty service record, I had hoped that it was simply not topped
off ever. Now, three months later, with only moderate driving, I see the
reservoir is virtually empty again. I don't see excessive white smoke in
the exhaust, or smell antifreeze in it - although I haven't sniffed it
specifically for that, yet. The oil looks fine. I don't smell coolant
inside the car, either. It would be hard to spot a slow drip in this wet
Winter weather. How common are internal head gasket leaks in this
engine, as opposed to slow leaks in the reservoirs?

 

Hi,
First I'd replace the rad. cap and see.

 

Good idea. I didn't realize that pressure leaks were such a common
problem. I may have the system pressure-tested if replacing the cap
doesn't work. Thanks.

 

I took the car to a local shop today. They do free pressure tests (I
gave them $20 anyway). No leaks, including the cap. Unless I'm missing
something, it has to be the #@!@# head gasket, right? Assuming it's
going straight to the exhaust and not burning much, how safe is it to
leave it alone? Any suggestions?

 

go for at least a 20 minute run, then look at the coolant reservoir
while the engine's still running. [make sure you can see in, but don't
lift the hose above the coolant surface!!!] any bubbles? if so, it's
gasket. also, check under the car and look at the bottom of the timing
belt cover. any coolant? if so, it's the pump.

 

low odds but this happened to me

i used some type of radiator additive that was supposed to kep things
cooler instead it made my honda go through radiator fluid and make me
think that i had a blown head gasket. I would try to flush the system
first and start fresh. Next feel the upper rediator hose with your
hand after warm up. Do you feel fluid and is the hose good. Low odds
but upper radiator hoses can collapse internally and are soo tough to
diagnose. Possible that the thermostat is sticking if no fluid
passing you have a problem. Next burp the system get excess air out by
adding water and squeeze the upper hose till bubles come out of the
radiator top fill hole repeat over and over till no more bubbles.

if still no progress either radiator shot, head gasket, water pump


start low cost and confirm all low cost items are good

 

Here's the problem: I have an appointment *tomorrow* to drop the
car off to have the timing belt and water pump replaced, to take
advantage of a 2 week service sale. They will be replacing the coolant,
but I have to decide if I'm having them do the head gasket then,
obviously. BTW, the engine has always run perectly cool, even in very
hot weather, so I'm inclined to think the flow is ok...

 

The pressure test needs to be performed in two places.
1) the cooling system, and
2) the combusion chambers.

the first is done in conjuction with the introduction of UV dye to the
coolant, this being detected on the outside with a black light. The
second consists of shop air being blown into each combustion chamber,
then the rad filler neck being then inspected for bubbles.

There is a third test that uses special paper test strips dipped into
the rad filler neck. These change color in the presence of combustion
gases in the coolant.

Your problem is NOT the rad cap. If it were, the reservoir would be
FULL.

There is also the possibility of a worn water pump. In that case the
coolant would drip down the block under the timing belt cover and may
not be obvious. Findinig that leak means carefully inspecting the crank
pulley area.

Do not put this off. You WILL damage your engine, possibly badly. You're
supposed to check your coolant level every time you open the hood, or at
least once a week.

 

The procedure in the Honda manual online in the UK is to just use a
hand pump-operated pressurizer with guage, and see if the pressure drops
in the cooling system or cap. I don't know which they used at the shop...

Good point.

What I'm going to do, assuming I can even afford the cost of a new
gasket done by the dealer, is to tell them to look for leaks, especially
at the water pump. If they find none, I'll have them replace the head
gasket. Shouldn't they install the new timing belt and water pump for no
extra labor charge (they will be providing the parts, not me) when they
do the gasket? I'm also having the front oil seals replaced as a
preventive measure. Thanks for your response. If you could answer this
post before this evening, when I drop it off, I'd appreciate it greatly.

 

Seems like you're jumping the gun a little bit here. How low was it in the
reservoir? When you say reservoir do you just mean the overflow tank, or
the radiator?

In normal use, the system will settle out to where the overflow tank sits at
the "min" mark when the engine has cooled & the level will rise to around
the "max" mark when the engine is hot & has been running for a while.

I certainly would not spend money replacing a head gasket that has not even
been diagnosed. There is not enough info here to even say for sure that
there is a problem.

 

----------------------------

Where did you get this bit of misinformation? I've owned six Hondas and
the level in the reservoir never changes more than about 1", hot or
cold, summer or winter.

If yours changes that much, there's something radically wrong from what
the Honda engineers designed.

'Curly'

 

I get my bit of "misinformation" from the behavior of 27 different cars over
a period 38 years. Where do you get yours?

 

On my 91 Civic, after years of observation, I'd say it's at
more like the mid mark on the reservoir when cool, then
right at max when warm. I am just following the manual: If
reservoir level is at low or a bit above, then warm up the
engine, and add coolant to the max mark.

 

I know. On the one hand it may be nothing. On the other it could be
engine-threatening. The dealer told us in essesnce, that we can't afford
a new gasket - didn't even quote a price. And we wonder why cars aren't
maintained like they used to be...

The reservoir was empty, or virtually so, both times.

 

then you either have a leak [which should be obvious somewhere - you
need to inspect properly] or you have a blown gasket. pressure tests
don't necessarily work for diagnosing gaskets unless the vehicle is at
full operating temperature. and even then... observing bubbles in the
coolant is the only sure-fire way of knowing.

bottom line, it's pointless spending money on the belt until you have a
correct diagnosis.

also, for repair economics, given the money that some repair shops
charge for head gasket work, it may be more economic to replace the
whole engine. you can buy a jdm import for a few hundred bucks and
replacement time is way lower than the time necessary to strip, clean,
prep and reassemble a motor for a gasket. and there's the problem of
repair shops using abrasives in preparation witch will in due course,
cause the car to burn oil. and there's the problem of many places
insisting on skimming your head, even if it doesn't need it.

 

---------------------

Sorry, misinformation is a strong word.

Volvos and Dodge products that I owned had pressurized reservoirs. The
coolant level in them went up and down with temperature, but the HONDA
isn't supposed to, since it's reservoir isn't under pressure at all.
Boiling hot coolant isn't supposed to take up much more room than cold
coolant, as long as the rad cap is keeping the pressure up.

Since about '92 most Hondas will self-bleed any trapped air because the
rad cap is the highest point in the system. When any trapped air is
forced out, the air is supposed to bubble through the reservoir and when
the system next cools, the level in the reservoir drops as coolant it
drawn back in. That's when the owner is supposed to add coolant up to
the MAX mark on bottle. The owner's manuals and the Helms service manual
all tell the same story.

However, none of this theory applies if there's a hole in a hose, the
head, the heater core, the water pump seal, or if the rad cap is shot.

'Curly'

 

sorry, that's fundamentally incorrect. coolant liquid most definitely
expands as it heats - for both systems. pressure doesn't stop coolant
expanding, it simply raises the boiling point.

http://en.wikipedia.org/wiki/Coefficient_of_thermal_expansion

 

I think we all agree that this motor should not be losing so much coolant
so quickly.
IMO,a coolant DYE test is in order. see if and where there's a coolant
leak.

 

then you need to go to a different service supplier.(but still use OEM
Honda parts)
It seems obvious this dealer just doesn't want to work on your car.

It's a FACT you're losing coolant fast;you need to find out WHERE.
A dye test seems in order.

THEN worry about head gaskets,IF necessary.

 

but most antifreeze already has dye in it already. and dye does nothing
to diagnose a head gasket.

as said by someone else, the o.p. needs to take this vehicle to a shop
that /wants/ to fix it - clearly the current one doesn't. time to hit
the phones.