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[MolDog]

Hi

I recently noticed that over winter my omega had been reaching temperatures of 100 degrees on the temperature gauge (sometimes a tiny bit over) when stopping after long runs.

Having had a look around it appears neither of the 2 cooling fans on the front of the radiator are switching on at all Even after running the engine until its about 95 degrees. Are these supposed to switch on at a certain temperature? Also is there some sort of thermostat in the radiator controlling these or are they activated from elsewhere?

[Big_Roger]

Hi,
The two fans at the front of the radiator are the air conditioning condenser cooling fans. They will come on at half speed if your climate control is on auto and provided you have sufficient refrigerant in the system and the system switches on the air con compressor.
When the condenser temperature rises then the fans will switch to full speed. You will know this has happened because of the fan noise and draught.  (the air con compressor and fans are switched off by pressing the ecco button)

The fan you should have coming on when the engine is hot is the one at the engine compartment side of the radiator. this is switched by a thermo switch that is screwed into the left hand side of the radiator.

It is a two stage switch. It switches the fan on slow speed first (fed through a resistor) then if temperature of water continues to rise second part of the switch comes on and puts fan on full speed.

All these operations are done through relays.

HTH

Roger

[Marks DTM Calib]

Hi

I recently noticed that over winter my omega had been reaching temperatures of 100 degrees on the temperature gauge (sometimes a tiny bit over) when stopping after long runs.

Having had a look around it appears neither of the 2 cooling fans on the front of the radiator are switching on at all Even after running the engine until its about 95 degrees. Are these supposed to switch on at a certain temperature? Also is there some sort of thermostat in the radiator controlling these or are they activated from elsewhere?

Actualy, the two aircon fans can also be switched in for engine cooling even if the aircon is off......so check the fuses in the engine bay ECU box....

[TheBoy]

Pop off the top rad switch plug, and short if paperclip. If fans come on, its the switch thats failed. Abou £20...

[MolDog]

Thanks for the replies guys. I'm going to run it up to temp tommorow and see which if any of the fans are kicking in. Didn't notice the fan on the other side of the rad until you mentioned it.

[MolDog]

Hi after checking again the fan at the back of the rad is coming on. This time the 2 fans at the front came on as well. So if its not the radiator fans I'm wondering what else could be causing it to get so hot.

I've already tried running just water round the cooling system a few times and draining it to clean it out a bit and the stuff theat drained out from the original coolant in there looked pretty clean, but on a long hard run it still reached 100.

Any ideas on what could be wrong?

[Big_Roger]

Hi,
If you don't have any recent history of leaking and having to keep topping up, or problems with oil in the cooling water, there is no reason why the radiator would suddenly be getting blocked up. Especially if the water cools OK when the fans do come on.

If you have just noticed the change in operating temp, my guess is it's the thermostat thats sticking or beginning to fail and not opening up enough.

Make sure you get system back to 50% Anti Freeze after all your flushing through.

[Big_Roger]

Hi,
Had another thought on this problem.
If the engine temp is OK all the time when you are moving, and only goes high when stopped in traffic but fans do run, then first suspect would be the thermo switch in the top (side) of the radiator has changed it's operating temperature.

It is certainly the easiest and cheapest option to try changing first.

The engine thermostats are a sod to do, and you need to be reasonably sure it's faulty before going down that road.

Roger

[MolDog]

Hi guys

Finally got round to getting this sorted.

Seems where I had my intake for my viper induction kit was not providing enough airflow. Had it jus behind/underneath the headlight next to the hole the original intake pipe went through, as I couldn't get the scoop on the end of the vipers pipe to fit through.

Managed to jam it in there as a quick attempt at fixing this before moving onto thermostrats etc. Took it on a long blast down the A3 from guildford to portsmouth and it seems fine now.

Will keep an eye on the temp guage for long runs but hopefully this has sorted it.

Thanks for all the advice anyways guys may well be back again if it starts doing it again.

[MolDog]

Well it hasn't really ended well. Was running fine for a couple of weeks then recently jus this weekend it started misfiring at low end intermitantly and temps started getting high again when idling/going through slow traffic. Finally today while I was cruising at bout 80 in 5th on the M1 it just suddenly went bang! (was goin a bit quicker on previous parts when it was clearer). smoke, bits of metal, oil leaking. Not sure whats gone wrong but guessing the head gasket. Well thats the end of that engine I guess either way.

[MutantCav]

Bits of metal sounds more like cam belt failure....or something along those lines...

[bobbertbear]

methinks bits of metal,smoke an oil leakage is more terminal like leg out of bed