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[Andy C]

Some of you may have seen this elsewhere, but trying to get as much info as possible!

I've been tempted by the cool running thermostats as sold by Courtenay et al.  I used to have a Rover K-Series, hence the fear of overheated heads!

Thing is, they all say they will cut the fan in around 10° lower than normal, but as far as I know, the X20XEV engine is thermostatically controlled to have the fans cut in at 92°.  Now my Omega tends to operate around the 85° mark during median temperatures with 22-24 on the climate.  Wouldn't this mean my fans were constantly on?  Anyone tried them and can give me real world input on this?

[hotel21]

Howdoo Andy.  Cant comment on the cool running stat but can on the engine temp - it may help ease a troubled mind!

My 3 ltr MV6 regularly runs with the needle on or a very small smidge below the 95/midrange mark on the readout, mainly irrespective of the cabin temperature setting.  At the height of summer with AC on full frezze mode, it ran steadily over the 95 but well less than 100.  This was, however, as a result of the following.....

When I first got the car, the temp was always over 95 and regularly hit 100 but no red overtemp light ever appeared, other than the lamp check when the ignition was first switched on.  The fans did cut in and cool things a little, but was almost always hotter than I would have liked.  Like you, I was wary and asked clever people on another Vaux site (before this one was here) and got good advice.

I replaced the waterpump at the same time as the belt and tensioners.

I ferreted around e-bay and got a genuine brand new vaux radiator for less than £60 delivered (iirc) but it was for an automatic (my car is manual) and so it had the auto trans colling pipes as part of the radiator core.  To me, this may continue to effect the cooling efficiency a wee bit.

I flushed the cooling system with a strong gunk degreaser solution (ran it for about 50 miles over a couple of days) then flushed it through to within an inch of its life!!   I then refilled with nice soft Scots tap water and red VX antifreeze at the recommended 50/50 mix.

Car now runs as per.

The clever peeps I took advice from earlier reconed that the cool running temp advantages were probably outweighed by loss of engine efficiency as the gibbles is designed to run on the hotter side of cool to get maximum efficiency.  My own experience of things mechanical certainly reinforces that things such as temerature are very much a design feature to ensure ideal operating conditions.

Its a long winded explanation of possibly nothing very much, but hopefully it may help out a little.

B

[theolodian]

The only time I ever messed with that was on a car with a severely undersized rad (small, beside ingine) AND I was running 50% more power than stock in a hot climate.  I can't see how it would help you.

What you are talking about is the fan switch.  I replaced the thremostat and the fan switch, no point having the fan running and the thermostat closed.

[Marks DTM Calib]

What you need to consider is that the oil temp is nicely maintained by the oil to water heat exchanger on the V6 power plants. Changing the thermostat would reduce the oil temp (possibly not preferred) and could affect the lubrication properties (depends on the type of oil used)

As for the statement that the rad fans will cut in 10 deg lower, they wont, your changing the stat i.e. the point at which the engine coolant is circulated through the radiator.....the rad fans are controlled by a separate thermo switch on the rad.

Remember also that with the air con on, the air con fans run constantly which also blows air across the radiator.....(warmed by the air con condenser)