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Bleddin Cooling system!

742 Views 5 Replies 3 Participants Last post by  Rage caliper
Hi, I have a MG ZR 1.4 2002 with a K series engine as always. I recently had a leak behind the inlet manfold, I changed that with a new gasket and while I was at it I changed the Thermostat too Now My car's cooling is Totally messed up.

after all the hard work I noticed the Fan stopped kicking, when and how it used too (normally when temps hit 88 degrees). I bought expansive coolant
that I took perstion mixing in order to get the Right mix... Now the crazy bit is, I have been Trying to bled this system Like No Mans business. I was trying to Back flash the cooling so I got a garden Horse and put it to at the bottom rad pipe but No water cam out from the top pipe (engine side) this was me learning how the C.system works so think it could not get round the therm as it worked the other way round. so I put things back and tried bleding it again and again using the bled value that is in between the Airfilter and block with No positive out come.

- NOw Heaters are blowing Cold even tho i was bleding while on High (max), they do get JUST warm NOT hot and to get them warm it takes what seems to be years (30min).
- The temp gauge also takes longer too to get up to normal temp

Can anyone Please please Help me on how to bled a system, if I need to have the engine on? which pipe first? what not to do? how to cheak all I well? Ohh as for the fan, It still does not kick in and i have even got a new sensor placed, relays and all fuses changed (when Unplugged it does spinn so Fan is in working order just not with temp)
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First off, is there any chance you have the thermostat the wrong way around? are you 100% sure that its in correct? the reason i ask is if it is in wrong (or faulty) no matter how much you try to bleed it you will never get it to cooling properly-you won't get the air out.

The fan can be tested by unpluging the sensor to it and the fan should just power up as normal and stay on (default setting from EMU if sensor fails).

When bleeding turn the heater to hot-this will open the valve for the matrix.

From the description, it sounds like the stat has stuck open or is not fitted properly. If you had an air lock the engine would overheat.
The Thermo could not be put in the wrong way as the longer side of it had a provision for it and the whole thermo housing blots to the Dipstick so with a Pipe stinking out half way the housing that goes to the Heater matrix.... I will have a look at it again. The fan does work when Unplugged yes which is a good thing I guess as my thoughts are that the heater matrix has an airlock, because the pipe from/to the heater is the one that has the sensor to the Fan and if water is not passing over it the fan won't start. if I drain the water out by just pulling the pipe at the bottom of the Rad. how do I start the whole process of filling up the system should the engine be running?
The Thermo could not be put in the wrong way as the longer side of it had a provision for it
Lots of reports of it happening on these pages so I guess it must be possible.
Good News!!

I have It sorted!! the Thermostat seems to be working and the Fan has now started to kick in and YES! I have Heating :chewie: just in time with this Bad weather.

Okay.. to get my system running, I drinned the system simply by Unpluging the bottom piple and let the water drain ( I even rasied the car at the back just to make sure) removed the cap on the tank and the bled bolt that even allowed more water out I guess from the Heater matrix.

after all that, I droped the car back down.. put the pipe back and the bled srew back (not too tight),heater was on Max and even the blower. At this point I had the A.freeze mixed and ready to be poured... i started the engine and slow started pouring the A.freeze, the tank seemed to fill with only one jar so I unbolted the whole Tank and lifted it above the engine as this helps with removing the airlock (GCSE Siecnce LOL). the water then just rushed down and into the engine and I kept toping up and repeating the process. I could see bubbles round the bled valve which was a good sign that the air was coming out, all this was with the cap off the tank. after 30min the Heater started blowing warm air and that was getting hotter and hotter... eventually The Fan Just start :bgrin2:. I continued topping up the A.freeze with the bled valve a lil open so to see the bubbles out. soon as the bubbles stopped I gave it a lil more minutes then closed the cap On the tank First the pressre increased on the bled vavle with lil more bubles seen. after all the bubles where done I tighted the screw and 2min later the Fan Kicked in again.. and cut out when it was ment to and I concluded that with the heating working the fan coming on and the water in the tank staying at the same level My system looks to be workin FINE!

Thanks to all the help from you all... and hope this story helps any with the same problem
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