G27 cooling system
Discussion
following cooling issues:
yesterday i drove my G27 for a longer distance on the motorway. (outside temperature aorund 0degrees)
temperature gauge didnt climb up more than 50degrees.
later, driving in town with lots of traffic, the temperature rised up to 85, the fan cut in...so erverything ok there.
temperature sender for the gauge sits in the thermostat housing (towards engine).
sender and gauge are matching.
thermostat is fitted and opens at requested temperature.
i have a similar phaenomenem also in summer, where the temperature on longer motorway trips does not climb up more than 65 to 70 degrees.
any ideas?
yesterday i drove my G27 for a longer distance on the motorway. (outside temperature aorund 0degrees)
temperature gauge didnt climb up more than 50degrees.
later, driving in town with lots of traffic, the temperature rised up to 85, the fan cut in...so erverything ok there.
temperature sender for the gauge sits in the thermostat housing (towards engine).
sender and gauge are matching.
thermostat is fitted and opens at requested temperature.
i have a similar phaenomenem also in summer, where the temperature on longer motorway trips does not climb up more than 65 to 70 degrees.
any ideas?
the radiator is a relatively small VW Polo one.(as recommended by Ginetta)
but in town, during traffic its already on the limit, even in winter time.
due to the bonnet construction of these cars the air is forced to go through the radiator, so overcooling on motorway could be exlained by that.
on the other side: if the water is too cold, the thermostat wouldnt open the circuit through the radiator.
but in town, during traffic its already on the limit, even in winter time.
due to the bonnet construction of these cars the air is forced to go through the radiator, so overcooling on motorway could be exlained by that.
on the other side: if the water is too cold, the thermostat wouldnt open the circuit through the radiator.
GinG15 said:
the thermostat is ok.
If it's been acting like that all the time, fit a hotter thermostat.The cooling system needs to be big enough to dissipate all of the heat created at maximum power.
When stopped and idling the water pump is turning slowly, reducing the water flow. At speed it's the thermostat that should reduce water flow to the needed amount.
The temperature gauge is correct and calibrated and reading the block temperature?
Have a heater fitted?
Has it always done this or is it something more recent following changes?
XE's are not known for over cooling like the Zetecs are if not plumbed in correctly so to offer any more advice it would be necessary to post a few pictures of how the engine is plumbed in.
Andrew
Have a heater fitted?
Has it always done this or is it something more recent following changes?
XE's are not known for over cooling like the Zetecs are if not plumbed in correctly so to offer any more advice it would be necessary to post a few pictures of how the engine is plumbed in.
Andrew
can you be more pricise, please?
by the way: the pressure cap is a double valve one (with 2 seals), overflow goes into a bottle.
to point out: i havent done the engine installation nor the design of the cooling circuit. it came as in the pictures. as it didnt show any signs of overheating i left it as it was.
by the way: the pressure cap is a double valve one (with 2 seals), overflow goes into a bottle.
to point out: i havent done the engine installation nor the design of the cooling circuit. it came as in the pictures. as it didnt show any signs of overheating i left it as it was.
Edited by GinG15 on Sunday 14th March 20:55
GinG15 said:
the thermostat is ok. it opens to the requested temperature and is fully closed when cold.
as a test i removed it completely and there was not much differnce....
Surely seeing not much difference when removed points to the thermosat not closing. How did you test the thermostat? and how do you know it closes fully. The fact that in town the engine reaches normal temperature and even needs the electric fan to cut in points to nothing really untoward. But not achieving temperature at speed (with higher revs?) really points to the radiator overcooling. If the thermostat is closed then the radiator has little if any effect so for the small cost of a new thermostat I'd just change it.as a test i removed it completely and there was not much differnce....
Just had another daft thought. Which way has the system been plumbed in (i.e. which way is the water flowing)? As your temperature sensor is in the thermostat housing (not on the engine block) are you measuring the temperature of the cold water coming from the radiator or the hot water going to the radiator. I know its possible to get the Zetec water pump to run backwards if you don't use an idler pulley and new belt.
to be honest: i´m not the specialist in vauxhall engines.
so i even dont know the flow direction of the water through the cooling system.
anybody has a diagram of it?
i checked the thermostat only visually by dismounting it when the engine was cold. there it was fully closed.
searched through the web and it seams that its not unusual for vauxhall thermostats not closing properly.
so i even dont know the flow direction of the water through the cooling system.
anybody has a diagram of it?
i checked the thermostat only visually by dismounting it when the engine was cold. there it was fully closed.
searched through the web and it seams that its not unusual for vauxhall thermostats not closing properly.
Darkspeed said:
XE's are not known for over cooling like the Zetecs are if not plumbed in correctly so to offer any more advice it would be necessary to post a few pictures of how the engine is plumbed in.
Andrew
Hi Andrew, I've just MOT'd my G27 with the new Raceline 2.0 Zetec and taken it for it's first run out. I too am having problems with overcooling and from your previous post it seems you know about this issue with Zetecs.Andrew
I have the Passat radiator with bottom hose going to the water pump (which has the correct Raceline idler pulley). The Raceline water rail moves the thermostat and pipework to the front of the engine. At the rear of the engine I have the temperature sender fitted to the water rail housing and half way forward along the rail I take off the supply to the heater (before the thermostat). The heater return goes into a tee in the bottom hose between the radiator and water pump.
Any help would be appreciated.
Cheers,Tony
Gassing Station | Ginetta | Top of Page | What's New | My Stuff