I have a 1999 Skoda Felicia 1.3 MPI 50KW

I bought this car 18 months ago, the car runs fine. On a run the temperature gauge reads halfway up the scale as normal.  But if I am stuck in traffic, the needle rapidly starts to rise and the radiator fan comes on.

As soon as I start moving again the gauge goes back to normal and fan goes off.  Like I say, the car runs fine but with cars I have had in the past the temperature gauge and the fan dont behave like this. I have changed the thermostat but the same symptoms occur. Could there be something wrong with the car or is it a quirk of this model.

Comments would be greatly appreciated

thanks

You didn't mention what type of Skoda Felicia you have.

On a warm day and being stuck in traffic, there is nothing wrong for the coolant temperature to rise and fan to kick on. It all depends on how 'rapidly' the temperature rises, and where the fan kicks in/out. There is definitely nothing model related.

 

Things that could aggravate the symptoms:

• bad coolant
• low level coolant
• radiator old/dirty/air flow restriction
• wrong type of radiator thermo-switch
• slight leak of head gasket

As long as temperature doesn't rise further even during hot weather with fan on, it's fine. Coolant temperature sensor is in thermostat, which is right after head, which is hottest point in circuit.

 

Fan switch is on radiator output, which is coldest place of circuit, and it is set to 94-99°C, so before it turns on, engine can get up to 105-110°. 

 

If you don't like high temperature reading, it's possible to fit switch from Estelle, which is rated at ~85°C, that keeps engine temperature below 95°, but fan runs more often, which in theory can wear switch and fan a bit quicker. Also, good quality switch will be hard to find.

As Papez said the felly cooling system is based around a mechanical thermostat and a thermo switch at the right bottom corner of the rad. 

There is approx 10c difference between the uppermost part (hottest) of the cooling system and the lowestmost part (coolest). 

So if let's say the car is fitted with 95 switch it will display 105 when the fan switches on. 

On mine I have changed out the thermo switch for a 85c one. 

They are a generic part that is available in any temperature and made by vernet (fits a lot of vehicles) . 

Also a cleaned flushed system as well as a very good expansion tank cap is essential. 

15 hours ago, Papez said:

it's possible to fit switch from Estelle, which is rated at ~85°C, that keeps engine temperature below 95°

Like @Stranraer I live in Scotland, and wouldn't recommend doing this because you'll have difficulties getting the engine up to the design running temperature.

27 minutes ago, KenONeill said:

Like @Stranraer I live in Scotland, and wouldn't recommend doing this because you'll have difficulties getting the engine up to the design running temperature.

 

Sorry, but this is nonsense. Fan switch on radiator doesn't affect engine's temperature, that's task of thermostat valve and I didn't say anything about it.

 

As long as thermostat valve works correctly, fan won't kick in until engine reaches running temperature, hot coolant won't reach switch when thermostat valve is closed. As I said before, radiator output is coolest place in coolant circuit, coolant temperature there is usually close to ambient temperature and rises only when there's not enough airflow through radiator.

1 hour ago, Papez said:

As long as thermostat valve works correctly, fan won't kick in until engine reaches running temperature,

So how does a lower temperature thermoswitch "make the engine run cooler" then?

49 minutes ago, KenONeill said:

So how does a lower temperature thermoswitch "make the engine run cooler" then?

 

It won't make engine cooler, it prevents engine to get hotter than running temperature. It sounds similar, but it's different.

 

Fan only provides airflow for radiator, when car doesn't move. Even if you connected it to run constantly, it wouldn't have effect on engine temperature, because once coolant reaches ~85°C, thermostat valve entirely closes and coolant no longer flows through radiator. Usually fan turns off long before this point, even with Estelle switch, which is set to ~70°.

 

It's quite different from heat exchanger in heating, that one is connected to small (or short?) coolant circuit, so coolant flows through it constantly. So if you turn heating on full, it is possible to reach lower, than engine's running temperature.

Edited 13 September, 20196 yr by Papez

Hi, I want to give my opinion/experience. I got a thermo switch of a skoda 120, it goes on at 77 degrees. The temperature gauge still goes up to the middle mark, so approx. 90 degrees as it should.

1 hour ago, nimbus said:

I got a thermo switch of a skoda 120, it goes on at 77 degrees.

Normal thermo Switch for Felicia switches on at 97°C and off at 92°C. Twenty degrees lower is bad for engine efficiency in terms of consumption. Moreover, 77°C indication on temperature gauge is much lower than middle mark. Something doesn't add up.

2 hours ago, nimbus said:

Hi, I want to give my opinion/experience. I got a thermo switch of a skoda 120, which is designed to switch on, when surrounding coolant reaches 77 degrees. Despite this, the temperature gauge still goes up to the middle mark, which indicates that coolant temperature in engine, measured in thermostat body, reaches approximately 90°.

 

Is this description precise enough, @RicardoM?

Edited 4 October, 20196 yr by Papez

Also while driving, the fan doesn't kicks in, even with a 77C switch. So for the engine, the consuption... it's the same as the original switch.

Anyway, it's the best mod i did on the car.

Edited 4 October, 20196 yr by nimbus

3 hours ago, Papez said:

Is this description precise enough, @RicardoM?

I really don't know what is your problem, other than looking for trouble.

 

1 hour ago, nimbus said:

Also while driving, the fan doesn't kicks in, even with a 77C switch.

While possible when very cold outside, I still don't see how the fan doesn't kick in during summer. Please explain.

26 minutes ago, RicardoM said:

I really don't know what is your problem, other than looking for trouble.

 

Sorry, I now realize that it might sound rude, it wasn't my intention. I just thought that nimbus's describtion was unclear, and some people might misunderstand it. I just wanted to help by editing text, so there won't be any confusion. I just want to know, if I succeeded. Again, sorry if it sounded rude.

 

33 minutes ago, RicardoM said:

While possible when very cold outside, I still don't see how the fan doesn't kick in during summer. Please explain.

 

Even in 30° heat, there's still 60° difference between coolant and ambient air. Do you think it's not enough to cool radiator by 20°?

 

It takes tens of seconds before fan kick in during summer.

Look how it goes and why it works as they say. 

At idle the rpm of the engine is low. 

Coolant flow is related to rpm as the water pump runs of the aux belt. 

So at idle the coolant takes longer to circulate the loop. 

Therefore it is in contact with hot metal more time than at higher rpms. 

That will mean higher temperature. 

Now imagine a hot pocket of water directly exiting the head. 

It will be let's say 100c so the gauge is going to show above the midlle line. 

The issue is that with low rpm this hot pocket of water is going to take more time to reach the bottom of the rad triggering the thermo switch. 

And after it is triggered it will take more time for the cool 😎 collant to reach the engine. 

This is called thermal runaway. And All felicias will do this on idle. 

Except the ones fitted with lower thermo switch

The reason being that the lower temperature of the coolant will result in a larger margin of q that can be absorbed WITHOUT going over 90c or the middle line. 

For every felicia this would require a different thermo switch based on rad condition, water pump condition, collant quality and so many other factors. 

For me a 85c thermo switch does the trick even in the hottest summer days here in Greece. 

Plus I have the thermostat removed. 

And I know you would say that the car is going to be harmed by no thermomostat. 

It is perfectly fine. 

It will still reach 90c even in the winter and on the highway it will drop down to 80c. 

Since fellys are prone to head gasket failure I say better keep it cool than hot. 

11 hours ago, RicardoM said:

15 hours ago, Papez said:

Is this description precise enough, @RicardoM?

I really don't know what is your problem, other than looking for trouble

Man calm down, you see everything written on this forum as a personal attack. 

For God sake no one here is deliberately trying to insult you in any way. 

Both you and Papez are knowledgeable members that contribute a lot to this forum there is absolutely ZERO reason to break our hearts over nothing. 

On 05/10/2019 at 09:34, Thefeliciahacker said:

Man calm down, you see everything written on this forum as a personal attack. 

Wrong. I can still see clearly when somebody is using unwarranted irony.

 

PS

Your long explanation for using a low temperature thermo-contact had one flaw. You forgot to mention in your previous message you are not using a thermostat.

You guessed it right, I find it harmful for the engine. If that was the case, Skoda would have used it as standard from factory for tropical countries. Instead they chose to use a 92-87°C thermo-contact for them. As for Felicia being sensitive to HG failure, my experience tells me that is true only when the owner forgot to replace used coolant, used bad coolant, or simply used water instead of coolant. I come originally from a tropical country and the latter "solution" blew a lot of HG from corrosion. Good maintenance and proper operation of the car prevents any HG failure.

Edited 6 October, 20196 yr by RicardoM

What irony? You are still accusing me fron doing those things, yet you are not able to explain or give example where I did it.

 

Only irony I see here that you are falsely accusing me for being too literal and obsedantly looking for your mistakes, (I'm honestly not aware of doing that with bad let alone doing that with bad intentions) while you're doing exactly same thing to others.

 

Btw, I confirm what you say about maintenance. My HG failed twice, once due to head corrosion (shortly after I bought the car, who knows what previous owner used), secondly due to my fault, where I topped coolant with water and forgot about it until winter, when ice crystals damaged HG.

Edited 6 October, 20196 yr by Papez

3 hours ago, RicardoM said:

koda would have used it as standard from factory for tropical countries. Instead they chose to use a 92-87°C thermo-contact for them.

As you can tell skoda did make many engineering mistakes as every other company does. 

I am not suggesting that what skoda should have done is remove the thermostat but because their setup worked with a brand new out of the box car for testing does not mean it you continue to operate well when performance of certain components has degrated

Quite the opposite, their cooling system is marginal at best. 

It has lots of issues that were kinda engineered around. 

But as the car gets older many issues are posed. 

Then it's the owners job to get an idea of what's the easiest way around the problem. 

For me it was a lower thermo switch and no thermostat. 

For someone else it may be a completely new cooling system. 

But I can tell you that no matter what if you don't overheat the car. 

The HG is going to last

@Papez @Thefeliciahacker @RicardoM - Look guys, @Stranraer lives in Scotland.  Where he lives it is rare for the air temperature to exceed 20C! I can't say about exactly where he lives, but where I live Felicias are still daily drivers.

@KenONeill I live in central europe. Winter temperatures can go bellow -15°, summer over 30°. I'm using my Felicia as daily driver in all traffic conditions. And Estelle switch works well, it doesn't trigger on cold engine and also doesn't trigger during driving in hot weather. 

@Papez Same here.

2 hours ago, Papez said:

Winter temperatures can go bellow -15°, summer over 30°

Also @nimbus - Which places the limits you're quoting outside what @Stranraer will normally encounter even in the hardest winter or the hottest summer heat wave.

Hi friends, my skoda Felicia 1.3 year 1999 to carburetor had the problem that the bulb burns and the fuse melts because the fan runs every so often. I discovered that the old owner had adapted a two-legged bulb, bought the original but now heats up more. I live in Ecuador and here the weather is hot 30 degrees.

@Jota - I presume you've had more than one fuse blow then? So, are you certain you're using the correct rating fuse and not too low a rating?