WTF thermostats

[colcol]

Whats The Fault with 156 JTS thermostats?
I have now fitted thermostat number FIVE to the 156 JTS!
First thermostat in the car was obviously a Genuine Alfa Romeo, Italian BEHR, it was in the car and after 6 years it was running too cold.
Second thermostat was a Genuine Alfa Romeo, Italian BEHR, lasted 2 years, before the car started running too cold.
Third thermostat was a non genuine, but the same as genuine, without the Alfa Romeo box, Genuine Italian BEHR, after 1 year started leaking.
Forth thermostat was a genuine Italian Facet, lasted 2 years before it started to take forever to heat up, but no leaks.
Fifth thermostat, genuine Italian Tridon, see how it goes.
From what i noticed, the new fully working thermostat, took, 5 kilometres to heat up to 90c.
The old Facet took 13 kilometres to heat up to 90c.
The new Tridon runs at 90c-95c most of the time in traffic, it goes up past 95c when stopped and then, it must open and the temperature drops back, or the thermo fan is cutting in.
I think with all the thermostat failures, the basic design must be faulty, as the different brands all fail within 2 years, the thermostat itself must be too small to last, it is indeed a very small thermostat.
I never thought a thermostat should be considered a 'consumable'.
If you have a faulty thermostat, then your engine will run too cold and the fuel injection mixture will be too rich.
This will cause excessive fuel consumption and carbon up the heads, requiring a  'decoke',       [ what is this, the 1950;s?].
Worst of all, as in the JTS, it will clog up the 2 cats, causing the 'motor control failure light' to come on and the warning buzzer to squark at you.
This will require a cat cleaner having to be put through the cats or worse, new cats at several thousand $$$$.
Keep an eye on that thermostat and when you get it replaced, keep a check on how far you have to drive before it gets to 90c, i have particular intersection now, that i can check on the warming up process.
The old 33 that i also drive had the original thermostat for about 20 years, that worked fine until i replaced it with a colder one, to help hot weather running in traffic.
The 33 thermostats costs about 10% of a new 156 thermostat, but lasts about 10 times longer, i think its called progress.
The 156 thermostat has lots of pipes and unions running off the housing and can not be replaced on its own as it is in the middle of the housing.
The 33 thermostat, sits under the housing and can be replaced on its own, therefore its 10% the price of a 156, Colin.

[Vittorio]

Hi Colin

Have you thought of replacing the sensor instead of the thermostat.
It may be that the sensor is giving false readings while the thermostat is working fine.


Vitt

[colcol]

These JTS have a bad reputation for failing thermostats, about a month ago, i replaced another thermostat, as it was taking about 13 kilometres to get to 90c, now the new one takes about 5 kilometres, with the same sensor, that is in the thermostat housing.
You can also see that during winter the heater doesn't work very well, the fuel consumption goes up and the spark plugs are dirty, due to rich mixture.
When purchasing a thermostat, the expensive ones have a new temperature sensor, the cheaper ones do not, so you have to use your old one, Colin.

[addem]

Hi Colin,

When your thermostat was going/gone how did the temp gauge act? I'm trying to work out if mine needs replacing or not. Currently it would take maybe around the 10km mark for it to get up in temp but I could be wrong as I commonly let the car warm up prior to leaving as it seems to help with the gear changes being smoother with the Selespeed.

When driving mine does the same is stop start traffic where it reaches 95-98 then drops when the fan kicks in but on a straight run or highways it can go below 70c and even as low as 50c. Would this be a stuck open stat?

Adam

[colcol]

Once it gets to 90c, it should stay there, freeway driving should not make it drop to 50c, also if it is over 2 years old it will most likely need replacing.
I don't know what brand of thermostat is the most long lasting, with my experience, they all last around 2 years.
They all could come out of the same factory for all you know, thermostats are not normally consumables, but with the JTS they are.
When you put a new fully working one, you will be amazed at how much quicker it heats up.
When i have purchased a new thermostat, i have tested in boiling water with a cooking thermostat, to see how the older one opens earlier and stays open longer, Colin.

[addem]

Ok so it seems that I should replace it

Went for a short drive, about 20kms, through the hills constantly between 2nd to 4th gear and it dropped to 50c pretty much.

How much is a thermostat roughly?

[colcol]

The price of a thermostat is anywhere between $80-$200 depending on the brand and postage and if it has a temperature sender or not, with the price of the $$ dropping, you should check local suppliers as they are cheaper because of the dollar, try Italian Automotive Spares or Alfamen, Colin.