Technical Dodgy thermostat?

[leonsdada]

Hi

Just wondering if you guys have had any weird experiences with QH (Quinton Hazell) thermostats in the past.
Just replaced my thermostat today and the running temperature seems to be higher than usual. Before the car used to run around 80-85 C, up to 95 in traffic and the fan would kick in.
Now, the car runs on 90 dead on, and the fan kicks in at about 100C. Too high for my liking, that's just asking for a gasket failure.
I am starting to think that the brand new thermostat is faulty. The build quality is certainly substandard, it looks cheap and the housing feels like is made of recycled chewing gum wrappers. I read some horror stories on a Rover forum regarding QH thermostats, which does not give much reassurance...
Tomorrow it is coming off. Not happy with it....

 

[purple haze]

Try a hot water bucket test when you take it off.

 

[Most Easterly Pandas]

It have said its not opening fully quick enough, running temp is fine but fan should kick in between 90-95 from experience (slightly earlier on some).

 

[Liquid Knight]

I don't think the thermostat would make the engine run hotter. Could you have an airlock in the plumbing somewhere?

 

[Dragon Man]

tough call, if the engine is running hot it normally means that the water is not going round the system fast enough. or you have blocked veins in your radiator.

if you drop the coolant out make sure you fill it up on a level surface. if not you get air lock:/ happened to me..

when mine started not cooling proply i parked it on a flat surface and it bled its self.. i know that 2 wheel drives have a slightly different cooling system though..
worth a shot if it helps..

 

[leonsdada]

Thanks for replies.

Finally got it sorted. I went out and bought a new thermostat, (again) to compare it against the other one.
It is also a QH (everyone seem to stock them, even halfrauds). upon close inspection, the batch number is different. I tested both several times with a boiling kettle and a little saucepan (very hi-tech, i know.. )
The first one took forever to open, and even longer to open fully.
The second was a lot quicker and the valve opened up considerably more.
I refitted it to the car, and my temperatures finally settled down. 80-85 on a run, 95 or so for the fan to kick in. Also replaced the fan switch at the same time, as I found the fan was not staying on for long enough, all good now.
Next time, I will definetely test before I fit. Luckily there is a temperature gauge on the clx, otherwise I would have had no way of monitoring this until maybe too late.
Fiats like to blow head gaskets, so a £10 dodgy thermostat could have been the start of a lot more aggravation.

 

[purple haze]

Alls well that ends well....