So, do I have a problem....?

I think the first thing to do is establish if the fluid is coming from the header overflow.
Are there any dried fluid stains near the overflow exit, ie, on the chassis or exhaust?
The header fluid level should be about in inch down from the recess in the filler neck. If it is higher, it is possible the header was syphoning some off after the fluid was warm and expanded. If so, probably no issues.
The only other thing I can think of is a leak from the water pump seal. That may drip down at a similar location. Not sure why the header level would appear ok though.
Take her for another run with someone following to check?
Kevin.

 

Assuming that your temperature did not spike you should be fine. That said you would be well advised to bleed the cooling system as it is a good idea to do this from time to time. There are a ton of threads on this but here are the basics:

1. Park the car on a surface that tips the nose upwards (ie park the car uphill)

2. Start the car and let it reach proper operating temp thereby allowing the thermostat to open

3. Make sure that your heater is on FULL HOT. This will ensure that all of the coolant is circulating through the system.

4. On the top of your radiator on the passenger side, there is a small round knob which is used for bleeding the system. With the engine running, unscrew this knob so that coolant runs out. There is no need to take the knob off and after a few secs re-tighten.

Repeat step 4 2-3 times and you are done.

I'm willing to bet it was just an air pocket in your cooling system.

 

my only addition would be to point out that the coolant that comes out of the bleed screw will be scalding hot and under pressure and can cause second degree burns to your hands in seconds. I usually wear gloves and keep a wet cloth under the screw to absorb the coolant as it comes out (it damages paint). Open the screw VERY slowly and just long enough for any air bubbles to come out, then screw it back in again and snug just a LITTLE with pliers.

 

I thought the header tank was supposed to be about 2/3 full when cold.
My guess would be that if you filled it to 1 inch below the neck cold it would for sure spill over when it got hot--- coolant expands a great deal as it heats up.

 

Hi Marc,
I'll second Pantdino's guess. 'sounds like once the tank puked out enough of the excess fluid, the system was happy and the 'leak' stopped. If your tank is only down "an inch or so from the top," you may want to siphon another inch of coolant to allow the tank a tad more room to do its job.

Jim's '2/3' number seemed to ring a bell, here. Since my memory doesn't always serve, I fell back on that sage advice: When all else fails, read the instructions! And, I did. In the operating, maintenance and service handbook, from car n. 02132 [the red cover], on page 73, figure 40 shows the fill level to be 5cm [2in] below the top of the tank [base of the filler neck]. Turning to page 74, the narrative states, "Regularly check the mixture level in the header tank; when the engine is cold. It should be maintained approximately 3/4 full."
(Note in that very same book how the comma after 'tank' in Italian and French morphs to a semicolon in English. A useless bit of translation trivia...just thought I'd throw it out there. )

Hopefully, it's as simple as having too much of a good thing. However, if your tank sports it's original two-eared cap, it might be a good idea to have a shop test to see if it holds 12 psi/.9kg/cm2. Though it may not be part of your current issue, Marc, it would not hurt to check it out.
Keep us posted,
Coop

 

I bought a $5 radiator cap at O'Reilly's this spring (Murray 7013) and found that my overflow tank now stays much more full than with the old cap. The Murray is also a two ear design similar to the original and has 13 pounds pressure rating.

PS - I've never heard of water pumps being a common issue on the Dino so I'll bet your liquid was just from normal heat expansion.

 

Radiator caps come in different pressure ratings
I believe the one on my Dino is a Euro cap rated at 0.9 bar, about 13psi (0.9 x 14.7)
A 16 lb cap will raise your boiling point but make it more likely you will spring a leak somewhere, since the system was not designed for that high a pressure

 

Pantdino & Coop,

I should have known better on this forum than to throw out unchecked figures. Thanks for correcting me. I just checked and indeed see the handbook say "approximately 3/4" full. Not a very useful figure, as most of us would determine the fluid content by the level in the header. Since the header tank has a more elliptical than rectangular cross-section, an eyeball level is not easy to translate to volume. Life is too short to measure and work out properly. So I just went out to see what level I am ruining with. My fluid level is 2.5" down from the top flange. The base of the tank is 6.5" from same flange. So I make that 61% of the available height. Knock off the neck height and it's probably close to 75%. With Luigi's "approximate", I should be about right.
I also checked the pressure rating of the header cap. Mine has a 1.1bar (16psi).

Maybe it was just a sticking cap and slightly too much fluid. Unless it repeats, I would not worry too much.

Kevin

 

I use "2" down" from the neck as the US equivalent (on my 308GTB). You definately need to leave some air in there!

That should do it.

Also be aware that there are different pressure ratings on the caps themselves. A Tech Bulletin on our cars admitted the OEM one was a little weak against the pressures involved and 'upped" the rating one step.


HTH

 

Bump for Murray 7013
Looks like they've gone up in pirce to $6.99

Murray Temperature Control 7013 - Standard Radiator Cap | O'Reilly Auto Parts