Radiator Problem need help!

I have a mazda RX-7 and the radiator fliud flow straight to the overflow when the car is running and doens't stop when it should. Also after the car has been siting for a while I have to refill the radiator. I have replaced the thermostat and got a new camp for it but hthe problem was not fixed.

 

Kinda strange to join a computer geek forum and make your first posting one about cars. You might have more success solving your problem here http://www.rx7club.com/

 

Welcome to the forumIf I had a masda rx7 I'd take it to a masda dealer rotary engines are voodoo black magic But anyway radiators are sealed pressurised units if water is leaking out from "a pipe" something is leaking or a component is missing,radiators dont have overflows check the pipe cant be connected to a nearby nipple to cool an auxillary component such as the turbo

 

ROFL.

I fix computers and cars, so it doesn't bother me.

I'm not all that familiar with Mazda engines, but one thing that can cause these symptoms is an air lock somewhere in the cooling system. Many cars have a self bleeding cooling system, but it isn't always perfect. For example, some of the six cylinder BMW engines are an absolute nightmare to bleed, and give the same symptoms as a blown head gasket until all the air is removed (or will end up with one if they are run like this for long enough). One solution is to drill a small hole in the thermostat, to allow water to circulate before the thermostat opens.

It can be very difficult to distinguish between an airlock and a blown head gasket, because both will pressurize the cooling system. Most radiator caps (and coolant resevoir caps) have a relief valve which allows this pressure to escape rather than cause damage elsewhere (burst hoses / radiator / heater matrix etc).

One way that can sometimes give you a clue if it's the head gasket is to take off the radiator cap, put your nose over the radiator (not when it's hot) and see if you can smell fuel. With a blown head gasket there is sometimes unburnt fuel vapour which can be detected in the coolant.

Another cause of overheating is a blocked radiator core. Some Japanese cars are prone to this due to the design of the core itself. Think of cholesterol gradually clogging the arteries. With car radiators, a similar thing gradually happens as deposits from the water (more so in hard water areas) stick to the inside of the radiator, restricting the flow. In extreme cases, if you take one apart, it will look like it's been filled with plaster of paris. Some radiators have narrow arteries and it doesn't take much to block or restrict them).

Less common, (but does happen) is that the impeller on the water pump can erode away until it isn't able to effectively force water round the system quickly enough to cool the engine. Unfortunately it's virtually impossible to check this without removing the water pump from the engine.

The thermostat itself may either be faulty, or could even be of the wrong type for the car. The easiest way to describe the difference would be to say that most of them look like the stereotypical UFO, but some also have another disc attached to them. This extra disc blocks the bypass hole once the engine reaches operating temperature. If the engine requires this type of thermostat, fitting one without a disc will result in water constantly being pumped round the engine, without it actually getting to the radiator.