Temperature above 190.....

[Dr.Jeff]

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.

I believe most of the T-stats being sold are not actually for a Fiat SOHC, but a VW application that is very close to the same. The VW item has a slightly different outside diameter for the main plate. But the rubber U-groove seal is sufficient to make it work. Otherwise the VW part has the same depth, small end size, etc. And it is available in a wide selection of temp ranges and from a number of manufacturers - including high quality German ones. There are also "high flow" versions of the VW stat that offer a bit more circulation flow past it. Unfortunately it is much like the radiator fan temp switch in that there are a vast number of VW part numbers for the T-stat. But start by looking for one to fit a 80's Golf/Rabbit/Jetta.

 

[dllubin]

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.

I have heard that same story but unclear to me how air enters a sealed system unless something else is going on,

 

[kmead]

I believe my new thermostat is a 190 so I will see what that brings

 

[JimD]

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.

I have stainless tanks in my 85 and 86 Xs. I have never noticed air building in the rads and I do check them regularly. I do keep the tanks at least 2/3 full as well. I can see how the compartmentalized plastic tank offers more separation between the inflow and outflow streams.

 

[tvmaster]

Testing the fan is done by simply unplugging the sensor from the left end of the radiator and putting a test lead across the two contacts, this will cause the fan to turn on. Often times the sensor in the radiator is defective and must be replaced.

If the fan is running and it is an OE fan, you will know when it turns on, there is a definite vibration you can feel in the car.

The gauge is likely inaccurate in its exactness but it is indicating generally what is going on. They are all a bit different but they work well enough. If it is going into the danger zone I would believe it.

The fan doesn’t run often on my car in my climate, I can drive home for 20 minutes in 80 degree weather and it won’t run at all. If I run into a bit of traffic it may come on for the time I am stopped or after coming off the highway and waiting at a light as the car sheds the heat from running hard. In stop and go traffic you should sense the fan running periodically for short periods.

Some put a switch acting on the relay to force the fan to run as desired, in general it isn’t needed but it gives them peace of mind.

It is also possible to install a second fan which could be controlled by using a VW thermo switch in the radiator (they are the same size and thread) which when wired properly can use a second relay to start the second fan at a higher temperature. The VW sensor can be had with several temperature ranges for the two startup temps.

You may have a lot of air in the system causing your high temps and making it so the radiator fan won’t come on but it is unlikely to have that much air in the system.

Draining, flushing and refilling the coolant system is a good idea. Pay careful attention to bleeding the system as it is more involved than some other cars as the remote radiator has an air bleeder in the top left corner reached through a hole in the front trunk.

What do you mean by “test lead”?

I was told today by the local X1/9 racer/mechanic that both the new fan AND sensor installed by WD’s were faulty. He recommended a sensor replacement from a Golf Rabbit circa mid-70’s, as well as questioning what the point of the second fan was in the first place for a car without AC.

As my car was idling while being worked on, the fan/s turned on, and indeed the bearing on the new one sounded pretty nasty. Honestly, they rarely turn on. The temperature gauge was up around 210 I believe.

I believe the ONLY time I’ve heard the fans turn on is when sitting and idling without moving.

He kinda panicked a bit, bled the rad quickly, and then poured about a half-tank of coolant in the brand new tank.

So I would love to test all this on my own while not on the $120 hr clock.

I guess that starts with testing the fans, hence the ‘test lead’ question.

thanks

 

[kmead]

If you have two fans that work you can have the first fan come on at a lower temperature and the second fan come on at a higher temperature if you install a VW two temp sensor in the radiator. Depending on how your car is wired it could be as simple as switching a couple of wires or you might need to add a relay to separate their start temps.

Or you can wire both to come on at a lower temp by using a lower temp single temp sensor.

Either one is a good solution. Two fans are good if you spend time in traffic. Where I live I only ever hear the fan after coming off the autox course or waiting in line for gas at Costco on a hot day.

 

[tvmaster]

If you have two fans that work you can have the first fan come on at a lower temperature and the second fan come on at a higher temperature if you install a VW two temp sensor in the radiator. Depending on how your car is wired it could be as simple as switching a couple of wires or you might need to add a relay to separate their start temps.

Or you can wire both to come on at a lower temp by using a lower temp single temp sensor.

Either one is a good solution. Two fans are good if you spend time in traffic. Where I live I only ever hear the fan after coming off the autox course or waiting in line for gas at Costco on a hot day.

Yup, got all that from a previous post - simple is fine: they can both turn on at once, but…

How do you perform that ‘test lead’ exactly, and is there way to test the temp. sensor as well?

This was a suggested replacement to what the ’Master Mechanic’ put in: https://www.fcpeuro.com/products/audi-vw-engine-cooling-fan-switch-82395948182

 

[kmead]

Yup, got all that from a previous post - simple is fine: they can both turn on at once, but…
How do you perform that ‘test lead’ exactly, and is there way to test the temp. sensor as well?

A test lead is just a piece of wire whose ends have clamps or the associated connector the other wire has. This allows you to bypass the offending part (the two contacts of the thermostatic switch) and see if the fans work.

If the fans come on you know that the fans are working when the thermostatic switch closes.

To truly test the switch you need to remove it and put the end of it in a pot of water with a meter on the contacts and raise the temp of the water until the switch opens. One needs a thermometer to know at what temperature the switch opens.

The rough way to do this is to get the car up to temp, park with the car running until the fan comes on and then get under there and using a non contact thermometer, measure the tank right next to the switch the next time the fans cycle. This isn’t as accurate but gets you in the ballpark of when the switch opens and the fans come on.

There are lower temp switches if you desire it to turn on the fans at a lower temp.

The fans are really loud FYI and move a lot of air, two of them will make quite a racket. The fans are available used and generally in good condition as they are rarely used on these cars.

 

[tvmaster]

A test lead is just a piece of wire whose ends have clamps or the associated connector the other wire has. This allows you to bypass the offending part (the two contacts of the thermostatic switch) and see if the fans work.

If the fans come on you know that the fans are working when the thermostatic switch closes.

To truly test the switch you need to remove it and put the end of it in a pot of water with a meter on the contacts and raise the temp of the water until the switch opens. One needs a thermometer to know at what temperature the switch opens.

The rough way to do this is to get the car up to temp, park with the car running until the fan comes on and then get under there and using a non contact thermometer, measure the tank right next to the switch the next time the fans cycle. This isn’t as accurate but gets you in the ballpark of when the switch opens and the fans come on.

There are lower temp switches if you desire it to turn on the fans at a lower temp.

The fans are really loud FYI and move a lot of air, two of them will make quite a racket. The fans are available used and generally in good condition as they are rarely used on these cars.

My concern was just that: my mechanic mistook loud fans for malfunctioning fans. I do have a cooking thermometer for water temps, so that’s a do-able test. What kind of meter do you put on the contacts?

The thermostatic switch trigger is replaced by the wire across the two leads, creating an ‘always-on’ scenario, right?

Is the thermostatic switch getting its trigger from the engine thermostat?

Adding the second fan theoretically brings the temp back down quicker, yes?

 

[Jefco]

The thermostatic switch trigger is replaced by the wire across the two leads, creating an ‘always-on’ scenario, right?

Is the thermostatic switch getting its trigger from the engine thermostat?

Adding the second fan theoretically brings the temp back down quicker, yes?

Yes, no, and yes.

 

[kmead]

My concern was just that: my mechanic mistook loud fans for malfunctioning fans. I do have a cooking thermometer for water temps, so that’s a do-able test. What kind of meter do you put on the contacts?

The thermostatic switch trigger is replaced by the wire across the two leads, creating an ‘always-on’ scenario, right?

Is the thermostatic switch getting its trigger from the engine thermostat?

Adding the second fan theoretically brings the temp back down quicker, yes?

Expanding on one of Jeff’s answers to your questions.

The engine thermostat is a very cool mechanical device which just responds to the environment it is placed in. Although it regulates the engine temperature, it has no inputs or outputs or any relationship to the electrical system of the car.

The way the thermostat works and it’s proper function affects the engine, warmup, cooling, general driveability and ultimately its longevity.

For a device with a simple spring and a wax filled vessel it does amazing things.

A meter is a multimeter and needs to be one of your tools. It does not need to be fancy. A continuity tester could do the same thing or a piece of wire from the one contact of the thermostatic switch to a 9v battery, another piece of wire to the base of a 12v light bulb and another piece of wire to the other switch contact will do (and be the same thing as a continuity tester).

 

[tvmaster]

Yes, no, and yes.

Expand on #2 then please - from where?

 

[tvmaster]

Expanding on one of Jeff’s answers to your questions.

The engine thermostat is a very cool mechanical device which just responds to the environment it is placed in. Although it regulates the engine temperature, it has no inputs or outputs or any relationship to the electrical system of the car.

The way the thermostat works and it’s proper function affects the engine, warmup, cooling, general driveability and ultimately its longevity.

For a device with a simple spring and a wax filled vessel it does amazing things.

A meter is a multimeter and needs to be one of your tools. It does not need to be fancy. A continuity tester could do the same thing or a piece of wire from the one contact of the thermostatic switch to a 9v battery, another piece of wire to the base of a 12v light bulb and another piece of wire to the other switch contact will do (and be the same thing as a continuity tester).

Essentially make sure the contacts on the switch open (?) aka continuity on the multimeter when your pot of water reaches the desired temp?
So it's the good old engine thermostat that drives the bus then...

 

[kmead]

Essentially make sure the contacts on the switch open (?) aka continuity on the multimeter when your pot of water reaches the desired temp?
So it's the good old engine thermostat that drives the bus then...

It drives the bus but controls nothing else directly.

 

[JKIDD]

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.

I've had my 86 X since 1989 & it always hovered around the 190 mark. In traffic it would jump slightly higher, but the fan would bring it back down quickly. that cycle continued as long as I was in traffic. Other than in traffic or idling for a while, the fan never comes on.

I sprung a leak behind the motor 2 years ago. I could see it was from the pipe from the water pump to the thermostat. I sourced a replacement pipe as I figured it had rotted & decided to refresh the system with new hoses, waterpump, thermostat, and complete flush with new coolant. I didn't like the thermostat I received from Vic's as it was smaller than the housing. I found the exact 1 I removed from Di Fatta Bros in MD. I don't know what the temp rating was.
After removing the old waterpump, I moved on to the pipe. SOB, the clamp on the thermostat side had broke causing my leak.... Too late now, I've already ripped in...

Got everything back together & proceeded to bleed the system. Went to turn the bleeder & it spun the whole thing off the radiator... I bought the "Texas Heat" aluminum radiator & temp switch. Direct bolt in & reused the OEM fan. Now my car is around 180, but I can't say exactly which thing, or all, did the trick.

 

[dllubin]

Essentially make sure the contacts on the switch open (?) aka continuity on the multimeter when your pot of water reaches the desired temp?
So it's the good old engine thermostat that drives the bus then...

The contacts on the switch should close, not open, when it reaches the desired temperature. If you measure it with an ohmmeter, the resistance should go from very high to very low when the switch reaches it's design temperature.

 

[tvmaster]

The contacts on the switch should close, not open, when it reaches the desired temperature. If you measure it with an ohmmeter, the resistance should go from very high to very low when the switch reaches it's design temperature.

 

[Jefco]

Expand on #2 then please - from where?

Fan switch changes state (off or on) directly from the temp of the water in the LH tank on the radiator, where it is located, just like testing it in the pan of water on the stove.

 

[tvmaster]

Fan switch changes state (off or on) directly from the temp of the water in the LH tank on the radiator, where it is located, just like testing it in the pan of water on the stove.

I would assume you can't remove the thermostatic switch unless you remove the coolant first?

 

[tvmaster]

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

From the service manual:

COOLING SYSTEM
Radiator and expansion tank. Water circulated by cen~
trifugal pump. Controlled by thermostat on cylinder
head outlet duct. Thermostat begins to open at 165° F
to 170° F (73° to 77° C).
Four-bladed fan, driven by electric motor. Controlled by
thermostatic switch in radiator. Thermostatic switch
cut-in about 194° F (90° C)