The 75 and ZT Owners Club Forums

The 75 and ZT Owners Club Forums (https://www.the75andztclub.co.uk/forum/index.php)
-   Technical Help Forum (https://www.the75andztclub.co.uk/forum/forumdisplay.php?f=11)
-   -   schematic diagram of cooling system (https://www.the75andztclub.co.uk/forum/showthread.php?t=57748)

markb63 1st April 2010 23:28

schematic diagram of cooling system
 
hi , does anybody have a diagram showing the directional flow of the cooling system ? .
my reason for this is , i have changed my rad and fan ( thanks for the kenlow jules ) cleaned out the matrix removed the engine drain , refilled the cooling system with oat , still not getting red hot air out the heater .
i have also done a mod on the cooling rail , car is not overheating and running fine,but the bottom cooling rail is not getting as hot as it should i think ...
so i now think that the problem lies with the thermostat not allowing the coolant to circulate ?

sometimes the heater blows warmish air on low fan , but i think when its on fast because the flow is not good enough the blower is cooling it down , without the fan on both flow and return on the matrix are red hot .
your thoughts please thanks mark

T-Cut 1st April 2010 23:57

It sounds like an air lock in the heater circuit to me, but I'm intrigued by your 'mod on the cooling rail'. Could that be connected to the problem?

TC

markb63 2nd April 2010 07:10

the mod to the cooling rail was done with silicone hose and two sections of stainless steel with the ends beaded over , my mild steel rail was in very poor condition and xpart said they did not have a stockist any more..... i refilled the cooling system with nearly 8 ltrs of mix and allowing for over spill from bleeding is near as dam the 7.2 .

have read of several posts of fellow members who say they have no air lock but heating is not good , even members who have used the pella.

just thinking that there is a different problem that we are missing , so does the thermostat control the flow round the system . my water pump was replaced approx 39 k ago with belts ...

if everybody thinks its an air lock , i have to take there advice as i have only owned the car for 2 months and most of you have been tinkering with these cars for years .

if thats the case then will hhave to try and get hold of a pella or take a trip to lates , how much do they charge to empty and refill a system ( ball park figure ) cov not to far from me .... i wonder if they are open over the bank holiday , this is doing my head in now :(

Lates 2nd April 2010 10:32

Quote:

Originally Posted by markb63 (Post 499600)
take a trip to lates , how much do they charge to empty and refill a system ( ball park figure ) cov not to far from me .... i wonder if they are open over the bank holiday , this is doing my head in now :(

Drain and refill no more than half hour using a vacfill.Cars queueing at the moment until end of May

rrobson 2nd April 2010 10:41

i very much doubt its the thermostat, if it wasnt opening you would certainly know about it, as the engine would quickly overheat. however, if it was stuck open, your engine wouldnt get upto temp. thermostat allows coolant to circulate around the engine once open, nothing to do with the heater matrix. when the thermostat is closed, the water inside the engine and the heating system is allowed to heat up, which is why the heaters should blow warm before the thermostat opens. once to the correct temp, thermostat opens and coolant flows through the engine.

within the dash, there are control flaps, which basically mix warm and cold air so the temp on the atc unit is near enough what is coming out of the blowers. sounds like either the temp sensors is broken or reading wrong, the flap which controls warm is stuck closed/partially open, or the flap which controls cold air is stuck fully open, if there isnt any air in the heating system.

markb63 2nd April 2010 11:18

thanks robson, have covered over 300 miles and no overheating or coolant loss :) , which temp sender ? thanks mark . will keep that in mind thanks lates

rrobson 2nd April 2010 11:39

Quote:

Originally Posted by markb63 (Post 499680)
thanks robson, have covered over 300 miles and no overheating or coolant loss :) , which temp sender ? thanks mark . will keep that in mind thanks lates

im not sure tbh, there is a bumper mounted one, however, if the temp on the display between speed and revs is correct or fairly close, it wont be that. there is also a cabin temp sensor, and if thats playing up then it wont be delivering the selected temp on the atc. the sensor is behind the steering wheel at sort of the 7 o'clock position, but i have no understanding of these. apart from the sensor and the air delivery, i cant think of anything else

markb63 2nd April 2010 11:57

outside temp sender working ok , will do a search for the cabin one ty :)

T-Cut 2nd April 2010 15:43

Is the pollen filter in working condition?

TC

James.uk 2nd April 2010 17:34

The in-car temp sensor is behind the lil oval thing with horizontal slots to the left of the steering wheel and approx 9 inches below the temp guage. I assume that should that get blocked in some way, the ECU will not be getting the correct in car temp readings and may restrict the heat to the car interior.. This is just guess work. But as air passes through it, it's worth checking and cleaning anyway. :}.
...


All times are GMT. The time now is 17:19.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd