1997 Accord internal coolant leak

First a little back ground. Cold winter and I started the car to let it
warm up, went into the house for 10 minutes. When I came back out
I found that the car had heated up a little( just over the 1/2 mark) Found
it weird but wasn`t overly concerned with it as I was running late for
work. As soon as I got moving the needle dropped back into the normal range
and all was good. The next morning I found I had trouble starting the
car. So a little looking under the hood and I notice that the radiator cap
has broken off ( holding in place but inside portion was broke). Buy a new
cap
(cheap one) and top the system up. The car that night started up after
numerous attempts.Still I haven`t placed the all the clues together here.
I look at the rad level and it is low again, so one more top up ( 10 ounces
at a time, coke can worth).Finding this weird I stop by Honda and they say
buy the
cap off them as the cheaper ones don`t hold the pressure good enough, sold i
buy it and install. Next day ; same thing,same time. So to sum up 60kms
(35mi) a day and I have to add 8-12 ounces of rad fluid. No external leaks,
one major symptom is the oil filler cap has moisture on it and no white
smoke billowing out. I go by the Honda shop and they tell me that they have
never heard of someone changing the head gasket on a 1997 Accord , to look
further, Any idea what else it might be? Car has 170,000 km .

 

I advise you to check the phone book for a radiator shop near your home.
The manager or owner should be able to determine if there are any problems
related to the cooling system. I believe that they can measure the
pressure. They can tell from the pressure reading whether or not there is
a leak or problem related to the cooling system. They can also check for
leaks.

 

Sounds like a hidden leak to me. The moisture on the oil filler cap doesn't
worry me in itself, but it might be wise to do an oil change and check the
drained oil for the milky appearance that indicates a lot of water in it. I
expect the moisture is from combustion (a gallon of gas produces right at a
gallon of water when it is burned), but it might be a good time to check the
plugs for the one or two having the unnatural cleanness that coolant leaks
from the head gasket produce.

Honda is right about the pressure caps - aftermarket ones are just no good
for Hondas.

Check the top of the radiator for a flat area on the passenger side. I don't
know about your '97 but my daughter's '93 has it and I've heard others
describe it. That area flexes with cooling system pressure and likes to
crack right down the middle, side to side. I laid a bead of steel filled
epoxy on ours, expecting it to crack off, but the crack surfaced through the
epoxy. I laid a much thicker bead and it has held. The coolant loss was
about what you describe, and the only traces of it (other than a coolant
odor in the garage) were on the fan shroud.

Beyond that, I second the idea of taking this to a radiator shop. Try to get
a recommendation, because there are good shops and bad ones. If you can't
get a recommendation, the dealer is usually a good choice. I think there is
a significant leak somewhere, and the sooner you can rule out or pin down
suspects the better off you will be. A leak that big means a risk of
overheating if you try to go too far and nothing good is happening right
now.

Mike