Why would the coolant be squirting out of the radiator overflow pipe after a solid drive? There seems to be no other leaks externally and no trace of water in the oil.

The temp gauge reads 180 when cruising and rises to 210 when driving hard.
It's filled with 50/50 mix coolant and distilled water.
The brand new Hot/Cold switch i recently installed has stopped working already.

 

Keep the coolant level at 1" to 1½" (cold) below the top, to allow for expansion, and it should stop.

Adding a coolant recovery system, would be the alternative.

Norm

 

Thanks for the reply!
I tried this, filled up to within about an inch of the top. Took it for a drive and when i park it up there's a substantial amount of coolant squirting out of the pipe still. I'd say the level is now about 3-4 inches down!

Is it possible i've got some kind of blockage in the flow ?
or perhaps a faulty temp reading and the engine is actually much hotter than i think?

 

Also, it seems to have only just started doing this.
Perhaps i've done something wrong in recent mods. Here's a list of things I have done recently:

Installed rebuilt Quadrajet
Added Pertronix Ignitor system
Added Sunpro temp and oil pressure gauges
Added new Heater Valve
Replaced Water Crossover pipe
Drained, flushed and refilled coolant system with 50/50

 

Best thing is to get an IR thermometer to take the exact temperature of your engine. If you are getting to 210, thats a little hot. The hotter the coolant gets, the more that will spew out (more expansion).
Does the car drive good when you are getting on it? If any lag or hesitation, the new carb could be running lean, boosting temps. Check for correct timing, too.

In any case, i would add an overflow jug, just to make sure there is always the right amount of coolant in the radiator at all times.

 

Maybe a new radiator cap would help...

 

maybe!
The current one has been cracked open more times than Amy Winehouse!

 

i've just been informed i should be worried about my head gasket, is this likely ?

 

Put a new 15# or 16# cap on it. I bet your problem goes away. Oh and by the way........is the radiator supposed to be that full? I run mine 3-4" below the top. I do have an overflow tank tho.

 

Are these overflow/recovery systems easy to install?
Any info would be greatly appreciated :-)

cheers all

 

it is possible but there other things also that can cause it. so don't be worried yet. most local auto shops will have a tester to see if it has CO2 in the radiator. they can test it for cheep. i do it for $20. or the kit only cost $65 from Matco.

 

my Rallye 350 also runs 3-4" below the top. but mine don't have a overflow tank. if you have a tank wouldn't the radiator be full all the time?

 

OK a further development.
I filled the rad to 2" below the lip and drove to work today very conservatively. The temp didn't get above 180 and when i arrived at work there was just a small amount of coolant exiting the overflow tube.
I've just taken it out on a straight road and floored it. When i returned the coolant was shooting out and it's extremely hot. Temp gauge only reads 200 though and has been like that for about 20 mins since i stopped the engine!!

 

I really doubt it's a head gasket. Try the new cap or have yours tested. You should be able to find an overflow tank off something. Or they make race types also.

 

How much coolant comes out? You really need an overflow tank for enviromental reasons and critter drinking it from puddles concerns anyway.
I would also check the cap.
Just put a coolant overflow recovery tank on and forget about it if isn't a lot and the car doesn't overheat. They are very easy to install, one tube from the overflow fitting to the tank. You need a coolant recovery system type radiator cap, some kits have a neoprene washer that converts your old cap to that type somehow, I just got the correct cap. One scavenged off another car will work as mentioned, you can also make your own. I picked up a couple of the tank kits in the closeout section at (The) Wal-Mart for 2 bucks each. Metal bracket, plastic tank, hardware and hose.

 

Sweet, cheers dudes

 

i just used a pop bottle for my over flow. works pretty good

 

does it need to have an airtight seal where the hose goes in?

 

Hose needs to have its opening at the bottom of the bottle. Bottle cap should have a tiny vent hole in it.
If using a pop bottle fill bottle half way, put the hose in the top opening and push it almost all the way to the bottom. Then put some foam around the hose and the opening to seal out debris but allowing it to vent.

 

success!
New rad cap and a home made expansion bottle.
I did it with an old 2 stroke Putoline coolant bottle strapped to the aircon
Took the car out for a run, it's 75 degrees here today so it was likely to run hot anyway. The car peaked at 190 even with a bit of blasting here and there and when I got back, there wasn't even a sniff of coolant escaping!

Job done, thanks chaps