ZX 1.9 D - Cooling System Problem

billy_bob · Post by **billy_bob** » 15 Mar 2004, 17:30

Hi All,
My 1997 ZX [135,000m] has big cooling problems:
First, I fill the radiator and bleed the system, top-up the coolant and bleed again -extra expansion tank in place throughout.
Then take the car out for a 30 min drive to heat everything up. The heating works fine ... the thermostat seems to open just below 90C, fan kicks in as expected and all seems well.
However, when the car stops coolant is running farely freely from the radiator overflow pipe (just below the filler cap). When cool again the radiator is only 1/4 filled. After driving back home again the bottom of the radiator is cool to touch while the top of the radiator is hot. There is loads of pressure in the radiator and gently (carefully!) releasing the pressure/filler cap releases some of the steam before coolant is forced out of the expansion chamber.
Anyone know why this is happening? Experts, please help!!!

Brian Oblivion · Post by **Brian Oblivion** » 15 Mar 2004, 17:42

Sounds like a headgasket blowing, pressurising the cooling system & causing airlocks, possibly due to a blocked radator (or dodgy thermostat). Expect a flood of possible answers to your common problem. Get the radiator sorted out (exchange or try www.europeanradiators.co.uk)and don't drive it if at all possible. You might be lucky with the gasket.

billy_bob · Post by **billy_bob** » 15 Mar 2004, 18:58

If the thermostat is blocked would the large-large bore pipe coming from the thermostat housing to the radiator be heating up? It gets very hot ...

Brian Oblivion · Post by **Brian Oblivion** » 15 Mar 2004, 19:16

You need to get the rad to a specialist who can measure the flow in and out of the rad. If its not hot all over it sounds like its blocked at either end (and inbetween)or theres an airlock somewhere. If you haven't already in the past 2/3 years, get the rad changed and hope the gaskets not blown.
There's a boat-load of radiator/gasket related articles on this forum. Try using Search with some of your keywords e.g. radiator,gasket,pressure etc to locate some info.