"Bruce" > wrote in message
oups.com...
> I drove my '90 Civic EX sedan 1.6L (180k miles, 5spd) on a 65 mile trip
> last week (averaging 75mph, 3.5-4k rpm, no AC, ambient temp 85) and
> about 5 mins after I pulled off the highway, the temperature gauge
> slowly climbed to 2/3, up from its normal position at just under 1/2.
> Once I parked, I heard gurgling coming from the coolant overflow
> bottle. After about 4 hrs, I opened the radiator cap to check coolant
> level, it was still topped off even though about a cup leaked out of
> the top of the OF bottle. OF bottle was empty, however. I
> trepidatiously drove home, this time keeping my speed at 60mph or
> below, and had no problems.
>
> This was the first time since buying the car last fall I drove it at
> this speed for a prolonged time, have driven several 1/2 hr trips at
> less than 60mph since and no problem at all.
>
> There's no oil or HCs in the coolant, no coolant in oil, so I'm
> relatively confident there's not a head gasket problem, but who knows?
> This car's so old and only cost me $1000, so if that's the case it's
> junkyard time anyway. I plan on changing the thermostat, coolant hoses
> and rad cap this weekend, and possibly the thermal switch that controls
> the fan... don't recall ever hearing the fan run so that might be the
> problem right there (anyone know off-hand where this switch is
> located?). Perhaps the airflow at 70mph was enough to cool the engine,
> but after heavily taxing the engine for over an hour the flow at 30mph
> wasn't enough since the fan wasn't working? Maybe a collapsed lower
> hose? I changed the timing belt this spring and did water pump change
> then too... also, radiator is relatively new (according to previous
> owner).
>
> One other problem (maybe related, maybe not): I have noticed an
> intermittant squeal coming from the front left wheel that is in time
> with wheel rotation, and is more pronounced when I turn left. It's
> quiet during right turns, and whenever I apply even light brake
> pressure. This noise was very pronounced when it was running hot after
> the first half of my trip last week (only after I got off the highway
> and was driving for 5 mins at ~30mph on city streets). Possibly coolant
> leaking on brake pad/caliper?

I've got the same overheating problem... I replaced the radiator and
thermoswitch last spring and the problem was fixed - or so I thought. Just
today, however, I experienced overheating that occurs when sitting at a
stoplight for a long period. My radiator fan does not come one. I may
re-wire it to always be on when the engine is on.