Well the bottom of the coolant recovery tank cracked and has been leaking coolant. I repaired it temporary with JB Weld and have a new tank on order.

The problem is that, I refilled a couple times with just water till I was sure the leak was gone, and hoping to wait till I get the resevoir to add coolant. Anyways, after a decent drive, the coolant begins to boil and spill out/steam out from under the cap.

I'm thinking just a bad cap coupled with the fact the ratios in the coolant are majorly skewed towards just water, the boiling point is much lower then it should be? The car is fine when it's first started, no bubbles in that tank then, and it only starts to boil and loose coolant through boiling over/steam, etc the temp needle goes anywhere above anything other then dead center when I stopped in traffic after a while of driving (30 mins). Even then, cruising and driving is fine, just stopped. The highest temps the car saw before I realized the leak, was on that drive home, stuck behind a city bus, the temp needle raised to about 2 o'clock position. Turned the a/c off, cranked the temp to full heat and the engine temps dropped quickly.

So just grab a new cap and coolant and get the ratios right? What about the tank itself, could I use a different tank from some other model temporary at least? Realize getting the different hose sizes, correct volume, but be tough, be just something in the mean-time? Or should I have more faith in JB Weld? It appears it made it 50 mins all the way to work, so I dunno.

IF the tank is holding pressure, even a weakened mix of coolant won't boil at 18psi until up around 230.

Are you only filling the tank to the halfway mark, cold ? (Factory fill spec) If the tank only has an airspace of an inch or two at the top, as the coolant heats it expands quite a bit, which has to vent somewhere, so it blows off the pressure release and out it comes.

Watch it until the new tank comes in and do it correctly. Plenty of old threads in here on changing coolant. Read up on it all, also down in Northstar Performance.

This just it, not sure how much if any pressure that cap holds. It's a well used original, so, definitely will stop and grab a new one today/tomorrow. I have been filling it up halfway to the mark ('ish, can't really tell with a black coolant tank), but after reading all the threads on it, I haven't been burping it properly. Will do that correctly on the way home and see.

Fill to the cross bar at the bottom of the filler neck in th surge tank. Throw in some Dex for good measure - even a $20 bottle of coolant is nothing compared to the cost of a smoked motor.

Forget the JB Weld. Been there, done that. I got a couple of years out of it with a very careful job and a 24 hour set up, but it just started leaking on my neighbor (who I sold it to). Until now, I would have recommended it.

Well fingers are crossed big time. Drained the tank and filled it with coolant (Prestone any make stuff). The 'coolant' coming out from the motor was pretty much straight water, so just filled the tank with coolant. And what I think was the problem was that I either never filled it with water enough. I had to add water to get from work to the parts store (ways away), and I notice water would keep going into the motor. I also read the threads on how to burp it. Changed it up a tad, I drove the car a bit to bring the temps up a touch, adding the water, drove some more, then tighten the lid. Car was still running great to the parts store, so I finished my route from the store to my house and no issues. I previously was just dumping the water in there and tightening the lid. Probably caused an air lock somewhere in the system. Thanks guys for the help (hopefully! lol).

Well fingers are crossed big time. Drained the tank and filled it with coolant (Prestone any make stuff).

:eek: you may have just signed up for two year coolant changes. If the coolant did not have the Dexcool seal of approval it is not the right stuff for N*.

LOL, yea, owned N*s for 5 years now, definitely in the know about that ;) Just never had to worry about the cooling system for some reason with the Aurora. Everything else though, (except HGs TTL) transmission rebuild, struts, brakes, a/c 2 or 3 times, etc.

http://www.shamrockchicago.com/pics/PrestELAFBoth.JPG