Won't suck the water from overflow
 

I have an '87 mk3 turbo with a new (As of January) Japan-amoter. I recently was having over heating probs and blew the radiator. (A crack in the fill spout.) So I put on a new brass, all metal, radiator and water pump. The problem now is that it won't return the water to the radiator from the overflow. So I am still losing water.
I noticed extreme amounts of Leak seal in the last radiator. I attempted to flush the engine prior to replacement. There seams to be no clog in the return lines and I can blow the water back into the radiator when applying pressure backwards through the overflow. (With my mouth) The pressure is strong when hot and no leaks are apparent. I find no oil in the water or water in the oil. The cap that came with the radiator is a 16 pounder. The car exceeds stock specs for speed and power, 0-60 etc....so I know the motor is strong. The turbo is up to about 12psi. Everything is strong.
Frankly, I'm stumped. I just want it reliable so I can get on with more speed, power and handling related issues.
Oh, and the water light is continuously on.

The cap has a tiny little silver or brass looking valve on it. When an engine is hot, and some coolant flows over to the bottle, that little valve allows the coolant to be drawn back into the engine as it cools down.

Yours may be bad. Also, since it is done thru a vacuum, make sure you have a tight seal throughout the over flow hose and clamps. If not, it will suck air and not coolant back into engine.

Pearls of wisdom.

We all have those cheap a$$ stock overflow bottles.
I know I have to keep a constant watch on mine to make sure the cap is on propperly. Or that there is enough fluid in it.

I have been kicking around getting an upgraded catch can.

It may not be a bad idea.

They run between 70$ and 150$

no vacuum?
 

Hi!
My MA70 was having overheating problems , then I received an idea from another MA 70 owner friend .
The set-up : Fabricate a tee-piece to fit into the heater pipe on the inlet manifold side of the engine (-this allows for a free running water flow and allows you to bleed the heater ).-- into the tee-piece fit a 3-WAY ADAPTER for: a metal shrader valve (as used to pump up the tyres ) a pressure relief tap ( radiator drain ) and a 0-30 psi pressure gauge , now put the overflow pipe from the OVERFLOW BOTTLE into a clear container of water.
Using COLD water, pump up the system with a foot pump and watch the gauge rise until the water in the container starts to show bubbles- stop pressurising at this point-this is the blow point, next -( this is important!) -allow the cap to continue to release and note the stop point , if it continues to zero then the cap is not sealing OR there is a leak somewhere -external or BHG? this is for investigation !-release the pressure through the drain valve into the overflow tank -ideal for a hot engine, saves waiting for the system to cool before removing the cap!!!!!!
The cap SHOULD release around 13 psi (0.9 BAR )(taking several minutes to reach this point from cold on a running engine) . , STOP around 6 psi and remain so for a minimum of two minutes, no drop = NO LEAKS!! , run HOT at around 10 psi -- mine does and I am not losing any water now.a real morale booster.
With this in place as a permanant fixture you can get REAL-TIME pressure readout and watch your radiator cap performance.
I took the cap apart and added a 2 thou.stainless steel shim to slightly increase the cap pressure to reach these figures.

water light wont go out
 

Hi!
After filling my cooling system with new anti-freeze mixture I noted that the water light came on and stayed on after starting ,this is because there was an air lock at the thermostat housing and the sender was not reading that there was water in the system ,--strange? as I had just filled it up! showing full in the radiator.
The answer was to make sure that the bleed hole was at the at the top of the thermostat - move the water through the bleed hole by squeezing the top hose several times with the cap removed to remove any bubbles and note the water level in the radiater go down slightly , and also that the wire to the sender is working properly -earth it out and see if the light goes out?, all cured after a short investigation.
Light on? no water at that point!

C'mon, man! this is a 3 YEAR OLD Thread!!! I doubt this guy is still monitoring it.:crazy2:

Maybe not, but other people are still reading it

Huh oh i pray thats the answer to mine cuz i remmy mine is down how stupid im.