General Lazy Thermostat?

[Ben D]

Been using Torque Pro to monitor a few parameters recently and noticed my coolant temperature sitting between 73-80 much of the time once the car is warmed up so rechecked today with MES. MES shows pretty much the same.

I let the car warm up whilst monitoring temperature with MES and the thermostat seemed to open at around 80c, let the car sit until the fan came in at about 97c then went for a short drive. Quite quickly, the temp dropped and sat below 80c for the journey.

Can I safely presume that this is opening when it should and staying open (worn out in some way) or, could there be something else at play here?

Ambient temperature and coolant temperature started off at 18C which was approx 4C above actual.

TIA

Ben

 

[aurick86]

1. I thought the same thing, replaced the thermostat .. same thing.. 75-80 degrees C.
at least for the bravo T-jet, the 1.4 NA should be slightly hotter... but the thermostat is not compatible..doesn't have the hookup for cooling the turbo.

2. 97 degrees C seems way to much for the first speed ... use MES do a live test.. make sure the fan works on speed 1.... i have a feeling it's not.. it should come on at about 88 degrees C if i remember correctly.

 

[Ben D]

Thanks Aurick, I'm only looking into this as I know the car did not run that cool previously. Only change made recently is decat downpipe and forge induction kit. I'd expect decat to reduce under bonnet temps but not to such a drastic extent.

Just ordered a new genuine thermostat so at least I will know it's definitely ok. Hot air from heaters is not as hot as I'd expect just now either.

I'll check fans later today.

Cheers

Ben

 

[aurick86]

OK, i had a quick look, the t-jet thermostat is 80°C, the N/A thermostat is 88°C... not sure if it should start opening at 80°C or if at 80°C it is already fully opened.

 

[MrDerv]

Thanks Aurick, I'm only looking into this as I know the car did not run that cool previously. Only change made recently is decat downpipe and forge induction kit. I'd expect decat to reduce under bonnet temps but not to such a drastic extent.

Just ordered a new genuine thermostat so at least I will know it's definitely ok. Hot air from heaters is not as hot as I'd expect just now either.

I'll check fans later today.

Cheers

Ben

If you're not getting hot air from the heater, you have air in the cooling system and needs bleeding

 

[Ben D]

Definitely no air in there, coolant level has not budged since I fitted new rad about 6 months ago. Heater temp fluctuates with reported coolant temp, I've had air in other coolant systems and in my experience it tends not to behave like that, heat is intermittent and independent of reported coolant temp.

I'll put new thermostat in and hopefully it sorts it

Cheers

Ben

 

[aurick86]

Ben D: make sure you get back to this thread... I would really like to know what becomes of this.

 

[Ben D]

Ben D: make sure you get back to this thread... I would really like to know what becomes of this.

Should get new thermostat in on Saturday all being well, I'll come back with my findings. Hopefully that should sort it, if not I'm all out of ideas!


Cheers

Ben

 

[cmosfxx]

That's the normal temp range for a t-jet.
Don't worry about it.

Especially for a decat with a brand new rad you shouldn't see anything above 80c on a normal ride.

 

[Ben D]

That's the normal temp range for a t-jet.
Don't worry about it.

Especially for a decat with a brand new rad you shouldn't see anything above 80c on a normal ride.

Thanks mate, could it really be the reduced temps from the decat causing the reduction I'm seeing in coolant temperature? It is only recently that the car has been running cooler and the ambient temperature has not dropped that much yet.

I'll for the new thermostat and see if there is any change, I've bought it now and fairly sure the current one is original.

Cheers

Ben

 

[Ben D]

Ben D: make sure you get back to this thread... I would really like to know what becomes of this.

Fitted this afternoon and car is back to normal temp. New genuine thermostat starts to open at 79C. Let it run until it hit 88C, and went for a drive.
Dropped below 80C once as soon I was up to 60mph taking it easy down a hill, put my foot down a little and up to 86C. Drove about 30 miles and temp stayed between 81C and 86C, heat is back in the blower so all good, car is as it was pre low temp issue.

Could be you got a slightly dodgy thermostat, Aurick? I had one that was bad out the box for a another car.

Bit of a pain to change, tight for space without removing IC to TB pipe.

Cheers

Ben