General marea overheating help

[markieb]

hi all ,I have a 97 1.6 marea no a/c .it was overheating and fan not coming on.the bottom hose stays cold, top one hot.reaches top temp very quickly.the fan comes on when bridged and when it overheated and coolant went down onto switch the fan came on for a second, which leads me to believe the switch is not at fault.
i noticed coolant leak on drivers side ,so i have put a new water pump in yesterday,which was a very awkward job after which the car still overheated no fan still coming on bottom hose still cold so i took out the thermostat last night and tested it.it didn't open so i gave it a good clean out and it did open when retested though only about 5mm( is this OK).

when i put it back in and refilled the radiator it only took about a liter to fill it to max even though i had drained it from the bottom hose.is that all the rad holds?anyway the car is still overheating and the fan still wont come on. I've bought a new switch but i honestly don't think it's that as the rad is cold at the bottom and so is the hose. so the switch obviously isn't feeling the heat.

If anyone can help I would be glad to hear from you.also thanks Venters for the help with the post. I hadn't had me tea yet this morning .lol.:bang:

 

[MrMigs08]

Hmm certain it holds alot more then that (Cant quite remember but i know 1l is absolutely nothing for the cooling system so try avoid using your car at all now or you may damage the engine!

Im thinking alot of air in the system or a block in the radiator, so i think disconnecting both hoses and running a hose pipe through the radiatior system (With bleed screws out, top right from fan side i think) and seing if the hose water makes it through the system!

Also theres a bleed screw i think conecting towards heating system you should rip out because that i found out there was some air in my system from that (There are two pipes central of the car in engine bay mid height i think (following thermostat??, cant remember at a friends but i will take pictures when i go home!

 

[Venters]

No problem Markie. Im with Mr Migs on this one, id check the rad for an airlock or blockage failing that try running it with out tue thermostat just incase it is the problem.

 

[rat20v]

It should hold around 5 liters, you have to release the pressure, there should be a release screw on the rad on the left hand side and maybe the right (sorry only know the 20v for sure) there is also one near the back of the back of the engine, when realeasing the pressure make sure your water tanks lid is off too.

 

[markieb]

thanks for the replies lads,I took the radiator out last night and gave it a good flush,I also replaced the switch on the rad.when I put it back in this morning the whole radiator started getting hot and the bottom hose is also hot now. but I had to switch it off just before the red as the fan still wont come on:bang: on my marea the matrix is bypassed due to a leak so the only bleed screw I have is on top of rad.

I have bled it from here when engine cold, I can fill it till it flows, but when hot just steam is coming out of it.fan is working when bridged.I haven't driven the car for a week .Please somebody help me with this before I get carted off to the mad house lol.

If both hoses are getting hot does that mean the pump is working and thermostat? any ideas at all very much appreciated.

 

[Venters]

If you run it till hot and bridge the fan so it comes on and the temp goes down, then the thermostat and water pump are both working.

 

[markieb]

I'll go down and try that now thanks

 

[markieb]

Well I finally sorted it.It was an air lock all right.thanks for all the help lads.I tried bridging the fan when hot and it cooled down(thanks Venters).once I knew the pump and stat were alright I filled the bottle slowly with rad valve open and kept it running ,once the water start flowing out I put back in the valve and screwed on the cap ,left it reach temp and the fan cut in

for future readers always bleed ,bleed and bleed again 'cos I definitely didn't think it was an air lock,so it just goes to show.
Thanks again for all the help.:worship:

 

[Venters]

Superb. Glad it's sorted.

 

[rat20v]

Cool man, it took me 2 hours to bleed the punto, and about a week to get the marea sorted

 

[smutty]

Do you bleed the radiator when A) the engine is running, B) engine is hot but not running, C)cold, and if cold should the radiator cap be off!

 

[Neverth]

As my 20v does not have rad cap or bottom hoses, I bled it when cold (changed waterpump, fluids and thermostat). Two bleedscrews on the top, rightmost will overflow first, then it takes some time for the left to overflow.

Rad is now bled. You always want to do the initial fillup when cold, so there is water circulating in the system when you start it.

 

[smutty]

thanks for that might just blast the hose through the rad to clear out all the debris.