Spitfire Losing Coolant

[FlyingCat]

My 1980 Spitfire (1500 Federal), aside from running hotter than usual, is losing radiator coolant. It tends to pool on the ground directly under the engine (leading me to suspect it's not the heater... but it could be). It doesn't seem to be any of the hoses, which are all fairly new. My overflow bottle is all but full (but not overflowing... yet), so it's collecting coolant, but not sending it back. I've noticed fluid around the filler neck. The radiator has less than 1,000 miles on it since it was professionally flushed. The thermostat is relatively new, but I know that may not mean a lot. I'm not sure how old the radiator cap is. And, I suppose, it could be the water pump, or maybe the water pump housing, though I'm not sure how that could go bad.

So... any ideas where to start on this? Thanks!

 

[poolboy]

When the engine has reached it's Normal Operating Temperature (NOT) does the top radiator hose, the one from the T-stat, feel full, firm and warm when you squeeze it ?
And do what you can to observe where the coolant leak begins.

 

[bobhustead]

Is your fan belt tight?
Bob

 

[Andrew Mace]

Have you thoroughly flushed the engine block? Silt and gunk can really clog up the water passages, especially towards the rear of the block (coincidentally, that's where the drain plug is for the block -- RH side). Remove the plug and coolant should flow. I'm guessing it probably won't, so be prepared with a small screwdriver or similar to prod and poke heartily until coolant starts to flow. Keep prodding to be sure you're really opened things up, then flush, refill, etc.

 

[RGK]

Is it overfilled?

 

[LarryK]

Look at bottom of waterpump for the weep hole, behind pulley. Check core plugs and heater valve by manifold. Cap should be new to match radiator. Get a mirror and flashlight, look around in between engine and firewall, look inside under heater core. Do a radiator pressure test at prscibed cap pressure and watch for leak.

 

[FlyingCat]

When the engine has reached it's Normal Operating Temperature (NOT) does the top radiator hose, the one from the T-stat, feel full, firm and warm when you squeeze it ?
And do what you can to observe where the coolant leak begins.

I'll try the squeeze test. As far as trying to find where the leak begins, I've been working on that for months now.

 

[FlyingCat]

Is your fan belt tight?
Bob

As tight as I can get it, but it's worth a double check. Thanks.

 

[FlyingCat]

Have you thoroughly flushed the engine block? Silt and gunk can really clog up the water passages, especially towards the rear of the block (coincidentally, that's where the drain plug is for the block -- RH side). Remove the plug and coolant should flow. I'm guessing it probably won't, so be prepared with a small screwdriver or similar to prod and poke heartily until coolant starts to flow. Keep prodding to be sure you're really opened things up, then flush, refill, etc.

I haven't flused the engine block at all, much less thoroughly. I'm going to give a go. Thanks.

 

[FlyingCat]

Look at bottom of waterpump for the weep hole, behind pulley. Check core plugs and heater valve by manifold. Cap should be new to match radiator. Get a mirror and flashlight, look around in between engine and firewall, look inside under heater core. Do a radiator pressure test at prscibed cap pressure and watch for leak.

What would I be looking for at the weep hole? What would I be checking the core plugs for? And what is a radiator pressure test? As you can probably tell, I'm new to a lot of this, but I learn quickly. Thanks.

 

[FlyingCat]

Is it overfilled?

I don't think so, but anything is possible.

 

[LarryK]

There is a ester that goes on the radiator in place of cap. You pump up to cap pressure and look for leaks. Weephole will leak coolant. This is between seals in water pump. Core plugs can rust and leak. Those are what cover the hole in the block to let sand out after casting. Commonly callled freeze plugs. Only place car can leak coolant, radiator, crack in block, core plugs, hoses and heater core. Pressure tester will find leak fast.

 

[sp53]

I will often place a large piece of cardboard under the car while the car sits overnight and look up around the general area in the morning for the leak.

The weep hole is round about 3/16 diameter on the body of the pump towards the bottom of pump casting.

steve