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Hello

Driving tonight in minus 1, I noticed the temperature gauge drop right down to about a quarter (45 degrees).

Is this to be expected or does it mean my thermostat needs to be changed.

It also drops to about the same level if the heaters are turnt on when sat on my drive. (tried it yesterday)

Cheers
 

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When you say -1 do you mean C or F?

I've been working on my Fiat in the garage where I normally keep my Alfa Spider 2.2 JTS. That requires me to move the Alfa out of the way, so the Alfa has been run for only a few minutes for half a dozen times in a row recently. Therefore, I took it for a drive yesterday to give it a chance to warm up a little bit and, of course, I was watching the water temp. It warmed up to roughly half way (three o'clock) after only a few minutes.

In fact, I remember thinking that the heater on the new-to-me Alfa starts producing warm air much more quickly than many of my previous cars. The outside temperature was right around zero C. In other words, there wasn't any tendency to run cooler than normal.

Sounds to me that your thermostat might be sticking. Running too cool isn't good for several reasons.
 
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Yeah degrees.

Looks might I have to get a new thermostat. The car is a 2.4 jtdm.
 

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No scientific answer, but I've always kept an occasional eye on the temp gauge. I'm sure in the past it was always rock steady in the middle (90C I think) after warming up. However, this winter I have noticed that it often drops below the middle, not a lot, maybe 10C maximum drop, and then goes back up. I think it happens when the car is coasting more (eg going downhill on the motorway) where the engine would produce less heat. However, I would expect a good thermostat to compensate for that by regulating the water flow through the radiator.

It clearly works in general as it doesn't deviate much, but I'm sure it didn't deviate at all in past years.
 
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Where is best to get one from and what sort of cost am I looking at for the part?
 

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when I had my 156 1,9jtd i ran it from 74k to 220+k with temperature never on 90 celsius. allway around 70. thought that was normal...? when i say 74k, that was the state of the counter when i bought the car.
 

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i'd normally made it compulsory to change thermostat when i had the water pump and cambelt changed on the corsa becuase i couldn't afford for any of these to fail, as its dealing with pressure and heat. i just forgot to have it changed on the alfa in Dec last year but next time i will make sure. a small price to pay to get it changed but if it fails to open and pressure builds up then it may end up costing more, personally its not worth the risk
 

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...but if it fails to open and pressure builds up then it may end up costing more, personally its not worth the risk
The problem with them is that they fail to close rather than fail to open. I suppose its a "failsafe" design. Your car will just run cooler and cooler as the thermostat gets weaker and weaker. Unfortunately this means it will also use more fuel and potentially increase the wear rate of your engine as its always in the "warm up" phase.

James
 

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No scientific answer, but I've always kept an occasional eye on the temp gauge. I'm sure in the past it was always rock steady in the middle (90C I think) after warming up. However, this winter I have noticed that it often drops below the middle, not a lot, maybe 10C maximum drop, and then goes back up. I think it happens when the car is coasting more (eg going downhill on the motorway) where the engine would produce less heat. However, I would expect a good thermostat to compensate for that by regulating the water flow through the radiator.

It clearly works in general as it doesn't deviate much, but I'm sure it didn't deviate at all in past years.
Should be rock solid. If it's dropping then cold water is being let in. The coasting change should have no effect because if the engine is producing less heat the thermostat should close.

Also the temperature in the radiator is irrelevant. It has cold water all the time you are moving. The thermostat just opens to let a small amount in. If you stop then the radiator water will get hotter and at some point switch the fan on to get it back down again and ready for the thermostat demand.
 
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Discussion Starter #12
In the summer time my car always stays at 90. It must just be the cold weather causing it to drop slightly.

Today it was on the marking just below 90 degrees and it was colder today than it was yesterday.

What is the life expectancy of a thermostat? Any point in a cars life/mileage that it should be changed?
 

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In the summer time my car always stays at 90. It must just be the cold weather causing it to drop slightly.

Today it was on the marking just below 90 degrees and it was colder today than it was yesterday.

What is the life expectancy of a thermostat? Any point in a cars life/mileage that it should be changed?
In summer the 'Leaking' past a failed thermostat will be warmer water. Now it's cold the 'Leaking' is being shown by the guage falling. So it's not the cold weather causing it to drop, it's the failed thermostat causing it to drop.
 
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In summer the 'Leaking' past a failed thermostat will be warmer water. Now it's cold the 'Leaking' is being shown by the guage falling. So it's not the cold weather causing it to drop, it's the failed thermostat causing it to drop.
Cheers mate will get it booked in to be done.
 

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Once up to temperature the gauge should be rock steady. Some gauges are inaccurate and will be rock steady at 80 rather than 90. However, if your gauge is fluctuating it is almost certainly a defective thermostat.

It could be low on coolant - check the level. The sensors are designed to be in water, if the level is low enough and it isn't in the water it will read low or nothing or fluctuate as yours is. Where has the water gone though?

It could be a head gasket failing causing air locks in the water cooling.

Possibly, but very, very unlikely is that your antifreeze is weak and the water is freezing in the radiator. This can give some very strange readings and effects!

My bet, and the cheapest, is failing thermostat - change it.
 
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Discussion Starter #16
Cambelt and water pump changed when i got the car by AHM. Plenty of anti freeze in there and water level hasnt moved since. Never used a drop :)
 
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Once up to temperature the gauge should be rock steady. Some gauges are inaccurate and will be rock steady at 80 rather than 90. However, if your gauge is fluctuating it is almost certainly a defective thermostat.

It could be low on coolant - check the level. The sensors are designed to be in water, if the level is low enough and it isn't in the water it will read low or nothing or fluctuate as yours is. Where has the water gone though?

It could be a head gasket failing causing air locks in the water cooling.

Possibly, but very, very unlikely is that your antifreeze is weak and the water is freezing in the radiator. This can give some very strange readings and effects!

My bet, and the cheapest, is failing thermostat - change it.
Thermostat changed today and the car is already running better. Feels better any way. All work done by AHM and as ever a professional job.
 

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Thermostat

Hi, one watchout on this, I had a similar problem on my Brera recently. the gauge normally sits at 90 degs C as stated by other posts. I also noted that the heater was not giving warm air, checked water level and it was a bit low topped up still no heat. Just had it to the dealers and the head gasket gone! Its my birthday and its a grand for the work. Anyone had similar probs with Brear head gaskets?
 

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Hi guys!

I got mostly the same problem on my 159 2.2 JTS.
So it's warmin' up pretty slow, like 10-13 minutes till it makes the first move from 50 in -10...-15C. After that i start to move and it warms up really slow like 30 minutes for 90 degrees. By the way when i stay and rev it or when i accelerate with a huge revs around 4-5K, the temperature drops really bad like 20-30 degrees or even more.
Last winter everything was OK, the problem starts at summer.
So i changed thermostat. I choose to change the original one to Gates TH23582G1.
On the original one it says "Waxstat 95".
The real crap is that after the thermostat change - nothing changed in general.

Do you know - which thermostat is best for the change? Where can i find the same original thermostat "waxstat".
 
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