Chevy Impala SS Forum banner

1 - 14 of 14 Posts

·
Premium Member
Joined
·
10,064 Posts
Discussion Starter #1
Ok, here's the vehicle parameters: 91 Chevy Caprice with the L03 (305 TBI.)

Lately I've noticed my coolant keeps getting low. I'm having to add a little coolant on an almost daily basis. There's no leaks under the car, no visible leaks at all. No water on the floor to indicate a heater core, and the water pump and thermostat were replaced last year.
Saturday i hadn't checked to coolant level for a couple of days and the car ran really warm, almost overheating. After i refiled it, it ran hot again for a few minutes, but then cooled back down.
I've been keeping it topped of since and it hasn't even run warm, but where the heck is my coolant going? I keep thinking head gasket, but my oil is clean. One of the shop mechanics thinks I maybe have just a tiny gasket leak and suggests using a block sealer... I don't know about that stuff...
Anyways I'll appreciate any input anyone has on the subject.
 

·
Registered
Joined
·
6,846 Posts
Check the inside of your tail pipe. It should not have a "greasy" feel to it. If it does there's a definite possibility it's going out the tail pipe. Still,better than going in the crankcase...
 

·
Premium Member
Joined
·
6,358 Posts
wuts the ATF look like?
 

·
Registered
Joined
·
6,846 Posts
Oh,I hope not....Coolant will easily damage the frictions inside. Many no longer use the radiator's internal trans cooler for this reason...
 

·
Registered
Joined
·
1,642 Posts
I'll lay odds it a heater core leaking. I just had the same issue with my 96 SS and sure enough the heater core started leaking AGAIN, this is now the fourth heater core in 3 years i've replaced.
 

·
Registered
Joined
·
6,846 Posts
Easy to find out...Bypass the heater core by connecting the hoses together,or with a separate hose. Coolant will suddenly stop disappearing if a leaking heater core is no longer supplied with coolant...
 

·
Premium Member
Joined
·
10,064 Posts
Discussion Starter #7
Easy to find out...Bypass the heater core by connecting the hoses together,or with a separate hose. Coolant will suddenly stop disappearing if a leaking heater core is no longer supplied with coolant...
AH. That's what I'll do. Thanx.
 

·
Registered
Joined
·
8,199 Posts
Not mentioned yet

Look for shiny lime green stain at WP weep hole

or

Pinhole leak in hose, only manifests itself under pressure. Will also prompt higher temps by way of losing system pressure. To catch, must open hood immediately after driving under load and before hole has a chance to pucker up. If lucky will (not always) leave aforementioned faint green stain in the engine compartment where it is shooting under pressure.
 

·
Registered
Joined
·
11,207 Posts
Check the hose at the rear top of the intake manifold. I had a slow leak there, and the liquid never made it to the ground. It also evaporated before I could find it.
 

·
Premium Member
Joined
·
10,064 Posts
Discussion Starter #11
Well it appears to have been a faulty radiator cap. it would never leak when the car was running but I caught it leaking after I shut the car off and walked away for a while. which is pretty damn strange.
 

·
Registered
Joined
·
6,846 Posts
So,in other words you're Happy,Happy,Happy...
 

·
Registered
Joined
·
11,207 Posts
The pressure in the system goes up a little after the engine is shut off, because of heat soak. The engine internals are hotter than the water, and when the engine is shut off, the water in the block increases in temperature. The pressure becomes a little higher, and if you have a weak cap, it can push the spring that holds the seal in place...leak.
 

·
Premium Member
Joined
·
10,064 Posts
Discussion Starter #14
The pressure in the system goes up a little after the engine is shut off, because of heat soak. The engine internals are hotter than the water, and when the engine is shut off, the water in the block increases in temperature. The pressure becomes a little higher, and if you have a weak cap, it can push the spring that holds the seal in place...leak.
ah! thank you, it makes sense.
 
1 - 14 of 14 Posts
Top