'96 Saturn SL2 Leaks Coolant from reservoir Cap, Why?

Hi All,

What is the most common reason for coolant to leak out of the reservoir Cap?
The car does not over heat yet, but looses coolant from time to time. I'm
not sure but I think it may leak the most when cooling off.

Do the caps go bad? (It's a 15lb plastic pressure cap).

Could I have a blockage in the hose that runs from top of the the reservoir
tank to the top of the engine?

Cheers,
Jim

 

See comment on radiator cap below.

I've often seen radiator caps that go bad over time. The symptom would be
what you have described: loss of coolant. If the cap no longer holds the
full 15 pounds per its original design, then the coolant will fill the
recovery tank sooner and be pushed out the overflow while the vehicle is
running (or when it has just been shut down since the engine is very hot and
the coolant is no longer circulating.) Once the engine cools, the recovery
tank fluid gets sucked back into the radiator resulting in the low fluid
level when you check it when cool.

The simplest thing here is to replace the cap with a new one (they are
fairly cheap and easy to replace) and then refill the radiator to the full
cool line. With any luck this will solve your problem. If not, then you
will need to look for the real source of the problem (plugged radiator or
leaking heater core, failed cooling fan, bad coolant temperature sensor,
defective fan relay, leaking/defective hoses or water pump) keeping in mind
it could be a blown head gasket and you might be buring the coolant.

Good luck!

Bob

You could, but not likely given that you said the vehicle is not
overheating. Try squeezing the top radiator hose when the engine is cool
and see if you can see result in the overflow reservoir. This should verify
there is no blockage.

 

Bob Shuman wrote in message ...

Thanks for your suggestions.

It is only leaking at the reservoir cap (I can see it run out), the cap for
the reservoir is a 15lb pressure cap.

The hose I speak of is not a radiator hose, this hose is more like an over
flow hose about 1/2" O.D. and 5-6' long, but unlike an overflow hose it
cycles back to the top of the engine from the reservoir tank.

Cheers,
Jim

 

I agree with Bob. It's more than likely just a bad cap. They're dirt
cheap at your local parts store. Just wait until the car has cooled
down before you replace it. If that doesn't solve the problem, then
you're generating excess pressure in the system or the system is overfilled.

 

While its being discussed, whens the last time you changed your coolant?

 

Cap went bad on my 97 earlier this year. It used to throw up in the
driveway occasionally after shutting it down.

 

I remember some times like that, but it was me throwing up just before
shutting down. <G>

Ken

 

Assuming you're talking about too much beer, etc. Been there too.
Contrastingly on vacation a couple weeks ago I had a single Mai Tai on the
plane and got lit, then had heartburn and had to take a zantac. I've become
a total lightweight.

 

I don't know where that old tag came from!

Same here. My consumption has gone so low as to be, for any practical
purpose, zero.

Ken