coolant leak

First off, I just finished reading the entire FAQ! That said...

Just bought a '96 Prelude, and it overheated at the end of the 2 hour
drive home from the dealer. I checked cabin heat at the beginning of
the trip, and it was hot. Later on, I noticed the temp gage rising, and
tried the cabin heat again, and it wasn't hot at all. Opening the hood
I saw that coolant must have been squirting out of the water pump,
because there was coolant on the throttle body & surrounding areas.
After cooling, I saw that the reservoir was completely full, but it
looks like the radiator is empty.

I'm just wondering if it HAS to be the water pump, or if I might be
looking at a bigger problem, ie head gasket. I already bought a new rad
cap, and have a new water pump on order. I guess this would probably be
an ideal time to change the thermostat, too? 188k miles on this car,
and it doesn't appear to have been superbly maintained...

I guess I just wanted to see if anyone with more experience had any
advice for me, since I'm try to learn as I go here. Thanks in advance!

 

if it's just the pump, it's cheap to fix if you do the work yourself.
you'll need a special tool to undo the crank bolt pulley - go to
tegger.com and you'll see what's needed. change the timing belt while
you're in there, and also invest in the most important tool you'll ever
buy for this car: the helm manual. it's the honda factory shop repair
book. all the other books are garbage.

regarding diagnosis, the throttle body is up out of the way of the pump,
so before changing anything, make sure you have the leak location
correct. refill the radiator to the top, bleed, then watch as the motor
warms up. you'll see it leak. it may just be a hose. refill with
antifreeze and distilled water.

 

I had a crack on the front top side of the radiator on a 90 accord
that when driven would open up and the forward motion would spray the
engine. Took me a while to find it because it was on the front side.

Just a caution to check every possible source before you start going
in after the water pump.

Frank

 

wrote in

You've got a water leak!

Check all those little coolant hoses under the throttle body. There are
whole bunch of skinny ones for the IAC, Fast Idle valve and the thermostat
bypass. Check the two heater hoses as well.

Sounds to me like the coolant was too low to be able to circulate properly,
and so caused poor heater output and overheating. Once you fix the leak,
the car will probably act fine.

If the coolant gets too low, the sypohon system can't pull coolant form the
reservoir to the rad, so that's likely related to the leak as well.

 

Thank you for your reply!

Unless I'm seriously mistaken, the water pump is not pulley driven, but
rather driven by the timing belt, and IS, in fact, located right in
front of the throttle body. I'm confused, though, since it's on the
opposite side of the engine from the pulleys and the timing belt. I
don't know what else it could be, though, with all the coolant hoses
attached to it!

I did do what you suggested, and after a few minutes I saw the "leak"
-- it was shooting water up about 2 inches in the air from a hole in
the top of the pump (????) that I assume must be a weep hole.

Does something like that always mean bad seals in the pump? Or could
there be a blockage in the system? Before I filled the radiator, I saw
what looks like salt deposits inside, so I'm worried what the rest of
the system might look like....


jim beam wrote:
[snip]

 

Okay, I am seriously mistaken.

Apparently the leak is coming from what Honda calls a "BOLT, BREATHING
WATER" in the thermostat case. Isn't that where I'm supposed to bleed
the system after a flush & fill? If it's leaking from there, would that
mean a blockage elsewhere in the system? I don't really know where to
start, aside from a new thermostat. Any advice would be appreciated!

-Randy

 

Does that "bolt" look like a brake bleeder (nipple) valve? If so, it's
supposed to be tight except when purging air out of the cooling system...

JT

 

wrote in

That's NOT the "thermostat case", it's the upper rad hose connection! The
thermostat housing is at the upper end of the LOWER rad hose.

No. As Grumpy says, it may just be loose. Tighten to 7 ft lbs with a 10mm
wrench. Actually, it's far more likely it's been *overtightened* and
STRIPPED, causing leakage around the threads. If so, you can get a
replacement dirt cheap from the wreckers.

 

In case anyone was curious, it looks like it was a failed head gasket
causing my problems. Had a cooland flush performed, and coolant shot
out of the radiator when I tried to start the engine. Also ended up
finding coolant on one of the spark plugs... So now I've got an excuse
to upgrade to an H22A.

Thanks for your replies, everyone!