Temperature above 190.....

I respectfully disagree with some of your comments Karl. I've only lived in Vegas for a few years. Otherwise all of my car owning experience has been on the beaches of SoCal with ideal weather/climate conditions. And I do not believe 190 degrees is "normal" for a properly operating old car. A modern car yes, but not a vintage classic. I believe the normal operating temperature should not be above 180 under the worst of circumstances, and 170 in more ideal conditions. Yes that sounds a bit cool compared to today's cars, but in my experience that is where they live best, are most reliable, and experience fewest problems. We are not talking about when these cars were new, but today. This entire forum is FULL of X1/9 owners experiencing all sorts of mechanical issues, failures, and problems. So whatever it takes to keep the engine running in that range is necessary - stock or otherwise; radiator, fans, fan switch, thermostat, water pump, and all other components of the cooling system. However I've never lived in a sub-freezing climate either, so there may be reasons why someone would want their car to run hot...I don't know. On the other end of the spectrum is this desert. But neither of those extreme conditions are what I'm talking about. Regardless, if his engine is running over 190 degrees (and it does need to be verified that is accurate) where he lives, how he drives, in his X1/9, then I believe changes are in order. Again, just my view and I respect that yours is different. ;)
 
The engineers who specified the thermostat would disagree with you.

All else, I am in agreement with. :)
 
The introductory article on the X1/9 in a December 1973 issue of Motor magazine** (UK), remarked about what FIAT engineers did to create one of the first mass-produced mid-engined cars. The second para in the second column of the attached page describes the wind tunnel testing done to develop the cooling system. I have also read somewhere that the original X1/9 radiator was unusual in that the vertical fins were much more closely spaced on it than on any other contemporary car.


Motor_12_1973_02.jpg



I'd love to get a copy of the original publication, but I don't know from which week's edition in December 1973 the article come from, plus there are not that many people on eBay UK selling these old issues anymore.
 
Dan Sarandrea (Phila) said:
The introductory article on the X1/9 in a December 1973 issue of Motor magazine** (UK), remarked about what FIAT engineers did to create one of the first mass-produced mid-engined cars.
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Very informative article. I feel a little bit safer now as the design of the targa bar seems to be working. As a proof, it would have been nice to see some pics where people is crawling out from an up side down X1/9 with a scratch on their nose only.
 
When I bought my '87 back in '92 it had the same issue as yours: a brief history in chronological order:
-Changed all hoses on both ends.
-Replaced fan sensor on radiator (fan tested ok)
-Replaced radiator with aluminum.
-Replaced head gasket
-Replaced water pump
-replaced overflow tank with stainless (kept original cap)
-replaced thermostat and housing (from Midwest Bayless)

Fixed any leak as that would introduce air into the system.
Air bleeding at radiator a must.

After all those fixes, the only one that had a satisfactory result was the last one; replacing the t-stat and housing.

That was five years ago and during the summer, the needle on my gauge never clears the 190.
 
Joe F said:
When I bought my '87 back in '92 it had the same issue as yours: a brief history in chronological order:
-Changed all hoses on both ends.
-Replaced fan sensor on radiator (fan tested ok)
-Replaced radiator with aluminum.
-Replaced head gasket
-Replaced water pump
-replaced overflow tank with stainless (kept original cap)
-replaced thermostat and housing (from Midwest Bayless)

Fixed any leak as that would introduce air into the system.
Air bleeding at radiator a must.

After all those fixes, the only one that had a satisfactory result was the last one; replacing the t-stat and housing.

That was five years ago and during the summer, the needle on my gauge never clears the 190.
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That is an interesting point. Over the weekend another member had a stuck closed thermostat. On my daily X the temp only gets to an indicated 190 after driving hard or sitting in traffic (the gas line at Costco for me :) ), which suggests mine is stuck open versus fully closed or partly closed.

What is the lifespan of a OE thermostat one does wonder? Could it be the restriction we are all railing against?

Do you think it was the thermostat only or is there some reason you would think they housing was part of the issue?

On my daily X I am going to be changing the hoses, coolant, clean the radiator, clean the heater core, replace the heater valve, replace the thermostat, replace the long dead radiator thermoswitch (its been dead for years but isn’t much of an issue for me due to the climate here) and the thermostat. I hope this will bring all the systems back to ‘nominal’.

Where do you live (general vicinity) as a climate reference, as I said in my climate and driving habits the temp has never been an issue but the car has also never been running near its limit either.

Thank you for posting what your experience was, it is actual evidence like this that really helps which as we say in product development, one test is worth more than all the opinions of the development team…

You are one of those tests.
 
But was the new thermostat the same temperature rating as the old one? Or did he install a cooler one? Just wondering.
 
Speaking of thermostats, OEM Savara thermostats are not stock items readily available from our regular USA vendors, although they do pop up on eBay from time to time and IIRC Steve C selling on eBay Australia as "FiatFactoryAustralia" does have them in his web store, although exchange rates and long distance shipping can be a tough pill to swallow.

There are plenty of European eBay sellers selling aftermarket brands such as Gates.

In the USA, I get the impression that most X1/9 owners buying a new stat are going to end up with a Stant unit.
 
Dan Sarandrea (Phila) said:
The introductory article on the X1/9 in a December 1973 issue of Motor magazine** (UK)
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Dan Sarandrea (Phila) said:
I'd love to get a copy of the original publication, but I don't know from which week's edition in December 1973 the article come from, plus there are not that many people on eBay UK selling these old issues anymore.
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There are a few on eBay UK.
Motor Magazine. 1 December 1973

3E7C5391-E7C3-40AC-AE47-58B0B05D2B45.jpeg
 
kmead said:
Do you think it was the thermostat only or is there some reason you would think they housing was part of the issue?

Where do you live (general vicinity) as a climate reference, as I said in my climate and driving habits the temp has never been an issue but the car has also never been running near its limit either.
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I changed both at the same time, but I think it was a little of both. The housing was deteriorating around some of the hose outlets and had a gasket leak on one side. I bought both at Midwest Bayless. The T-stat is a 180 degree made in Italy (Jonson Heide) MWB part number 4222883.

I chased down several coolant leaks over the years and the car seemed to maintain a good running temperature when I no longer had little green puddles on my garage floor.

By the way, I use Prestone 50/50 coolant in all my Fiats.

I have always drove the car in New England (Mass & New Hampshire) and only in the summer. This past month we have had several days of 90 degrees plus and the car has maintained a steady temp reading of at or below 190.
 
kmead said:
If his car stays at 190, its a 190… :)
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Joe F said:
The T-stat is a 180 degree made in Italy (Jonson Heide) MWB part number 4222883.
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Hummm. ;)

Just because the engine runs a specific temp does not mean the T-stat is that temp. This is a big part of the point I've been trying to make. These engines were designed back in the 60's, and while I highly respect automotive engineers (often wish I had continued it as my major rather than switching to business) I do not necessarily hold their decisions to be true today. The design is ancient and the specs are antiquated. Plus engineers have to meet a lot of requirements that may not be the best choices for us. Furthermore for conditions that worked in 60's Italy may not be good for '21 America, lots of variables. Not to mention the cars are roughly 45 years old, things are not what they used to be, and the condition of internal components are not fresh new surfaces. So I go with what works for me today here, not what the Italian engineers said 50 years ago.

But I definitely agree that the cooling fans and the temperature switch that controls them are a major factor - not just the T-stat. And I agree the fan switch should be a lower temp than the T-stat. The reference I made previously about aiming for a worst case operating temp of 190, normal conditions of 180, is for a typical environment/climate and normal street driving conditions. Often this may mean a 170 degree T-stat and 160 degree fan switch, but it needs to be adjusted for each case. Any other factors/conditions will adjust those numbers. For example in the hot desert here I use a 160 degree T-stat and 150 degree 2-speed fan switch with two fans.

Again, my point was not so much the actual numbers as having everything working together as a balanced system.
 
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Joe F said:
I changed both at the same time, but I think it was a little of both. The housing was deteriorating around some of the hose outlets and had a gasket leak on one side. I bought both at Midwest Bayless. The T-stat is a 180 degree made in Italy (Jonson Heide) MWB part number 4222883.

I chased down several coolant leaks over the years and the car seemed to maintain a good running temperature when I no longer had little green puddles on my garage floor.

By the way, I use Prestone 50/50 coolant in all my Fiats.

I have always drove the car in New England (Mass & New Hampshire) and only in the summer. This past month we have had several days of 90 degrees plus and the car has maintained a steady temp reading of at or below 190.
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Makes sense: a 180 degree stat has the system equilibrium at 190

So a 195 stat keeping system equilibrium at 205 makes sense, too.
 
Michael Oxman said:
Before I do a flush and fill (per my post above), I wanted to test when the fans came on, so I let the car sit in the driveway for a while after a few mile ride. The picture below shows where they kicked in. That seems very high since everyone talks about their temps being under 190, but I see Dan S. posted the values below from the manual in another thread which shows they're in line. Does this look right?

Thermostat:
Starts opening: 172° to 183° F
Fully open: 194° to 201° F

Cooling fan thermoswitch:
Cut-in: 198° F
Cut-out: 189° F
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On our ‘74 1300, the radiator was replaced with aluminum, a second fan added, new temp sensor, thermostat, coolant tank, hoses, and water pump. When sitting idling, the fans seem to kick in above 205 degrees. Don’t think I’ve heard them turn on while driving, but the temp rarely goes above 205, if that helps…
 
Not to throw a curve ball at the discussion, but when I installed the stainless overflow tank it ran hotter...I replaced the cap with my old one from the plastic tank and it ran much cooler, not as cool as I wanted, but much better than the one the ss tank came with. I have not tested either cap for pressure.
 
Joe F said:
Not to throw a curve ball at the discussion, but when I installed the stainless overflow tank it ran hotter...I replaced the cap with my old one from the plastic tank and it ran much cooler, not as cool as I wanted, but much better than the one the ss tank came with. I have not tested either cap for pressure.
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Good point, system pressure also plays a role.
 
Joe F said:
Not to throw a curve ball at the discussion, but when I installed the stainless overflow tank it ran hotter...I replaced the cap with my old one from the plastic tank and it ran much cooler, not as cool as I wanted, but much better than the one the ss tank came with. I have not tested either cap for pressure.
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Do you think stainless runs hotter than painted metal, or is the cap most of the equation?
 
Joe F said:
Not to throw a curve ball at the discussion, but when I installed the stainless overflow tank it ran hotter...I replaced the cap with my old one from the plastic tank and it ran much cooler, not as cool as I wanted, but much better than the one the ss tank came with. I have not tested either cap for pressure.
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Some have suggested the stainless tanks induce added turbulence and introduce air into the coolant as the transition into the pool of coolant is quite different from the later plastic tanks. The added air builds up in the radiator causing higher temps due to the air reducing the cooling capacity of the radiator.

I can’t speak to the reality of this as my cars both have a plastic tank at the moment. I have a stainless tank on the shelf if one goes south.
 
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