Hi guys. This is a big mistery for me, please help me to find the problem.

I have a fabia (2004 classic, hatchback, 8v).

A few days ago i started climbing a ver long and steep uphill (4400 ft climb, that is 1341 meters, to get to the top, you need to drive an uphill of 15km). 7 kilometers into the hill, i started to smell coolant, and the temperature neddle started to move to the right. As soon as it started to move, i pulled over and shut down the engine. The fans where running normally, but the reservoir was nearly empty. A lot of coolant and steam was getting out of the reservoir from a small, vertical channel on the side (See the attached pic). I waited half an hour with the engine shut down. Then, i added more coolant to the reservoir, and finished the climb ok.

Before starting climbing that uphill, I had driven 100km, and the coolant level was at the middle. Everything was ok.

I let the car at the workshop. They changed the reservoir (Mine was very yellowish), the reservoir cap, they checked the fans (All the different fan speeds) and they work ok. Also, they changed the oxygen sensor (vag-com said it was bad).

After those parts where changed i made a test drive into that hill again. (I need to drive 100km to get to the begining of the uphill). When i arrived at the beginning of the uphill, i pulled over and checked the coolant level. It was in the middle. The oil was ok too. i put a few napkins under the coolant reservoir, to detect any single drop of coolant. Then, i started to go into the uphill again. This time, i was able to go a loooot farther than before. 13km instead of 7. but, it happened again. As soon as the neddle started to move to the right, i turned the engine off and waited. I took a picture of the reservoir at that time. The napkins where full of coolant. and the coolant was above the "Max" mark. But, when the coolant and the engine cooled down to ambient temperature, it descended below the "Min" mark. I added more coolant, and went downhill normally.

so, the problem persist :\

After that, i have driven more than 1000km with the car (City, highway, Fast driving (160km/h / 100 mph), and slow, stop start city driving), and the coolant is at the same, constant level (Between min and max). Its not burning coolant at all.

A few notes:

* The car only does that at long and steep uphills.

* The car was light when that happened. Only me (138lbs), and no bags.

* I was driving on second gear, at 3000, 3500 rpm.

* The A/C was off

* While driving uphill, it has a lot of power. It doesn't fell sluggish at all

* If i limit my self to city driving, highway driving, and start-stop traffic, the car doesn't overheat at all. also, its not consuming a single drop of coolant.

* The color of the oil is completely normal.

* The color of the oil in the oil cap is normal too, no residues of coolant.

* The color of the coolant is normal.

* The radiator was changed 2 years ago with a genuine skoda part.

* The reservoir, and its cap where changed a week ago (After the problem happened for the first time)

* The thermostate was changed 8 months ago with a genuine skoda part.

* I can drive as fast as i want, as long as i want on highways, not a single problem.

* There isn't steam or smoke on the tailpipe

* There isn't bubbles on the coolant reservoir.

* The radiator is warm to the touch, no cold spots.

* The system was drained and new coolant was added a week ago.

Thanks a lot for reading. English its not my primary language so i hope its easy to understand.

Edited 17 June, 201313 yr by cyberstudio

Can't help with your problem but your English is very good.

I would try another genuine Skoda thermostat, they can fail.

DB.

The system is over-pressurising so the coolant is passing through the cap and down the side.

I would get a block test done to see if there are exhaust gases in the coolant. My guess is that a crack in the head gasket (or block/head) is opening up at sustained high load.

Hi! Thanks a lot for your answers!

The system is over-pressurising so the coolant is passing through the cap and down the side.

I would get a block test done to see if there are exhaust gases in the coolant. My guess is that a crack in the head gasket (or block/head) is opening up at sustained high load.

Is it possible to have a head gasket/block failure, without the car consuming any coolant at all, and no bubbles on the reservoir? I would have thought that if you have a head gasket failure, or a crack in the engine block, the problem should appear everywhere and not just on steep uphills, but, im not any expert on anything car related

im not sure about the weather there at the mo but try running the car without a thermostat .... wont do any harm but will take longer for the car to warm up

Im in the caribbean, We're at 30-32 degrees C, or 89 F, the entire year. That sounds like a very good sugestion.

In the next few days, i will try and will update this topic.

Thanks!

at that temperature i dont think id bother replacing a thermostat

Hi! Thanks a lot for your answers!

Is it possible to have a head gasket/block failure, without the car consuming any coolant at all, and no bubbles on the reservoir? I would have thought that if you have a head gasket failure, or a crack in the engine block, the problem should appear everywhere and not just on steep uphills, but, im not any expert on anything car related

I would say, yes it is possible for a small gap to open up only under extreme conditions, like going up a big hill fast, in hot ambient conditions (your engine will be at/near maximum output for far longer than under any other conditions, and so be as hot as it ever gets, because speed is relatively low for the amount of power output, so airflow through the radiator will also be slow). Obviously Mr Baldwin also thinks this, and my impression is that he is something of an expert in car-related matters.

Under these sustained high output/high temperature operating conditions the thermostat will surely be wide open if it is working correctly, so omitting it will make little or no difference.

the thermostat will surely be wide open if it is working correctly, so omitting it will make little or no difference.

if it is working correctly? without omitting it how do you know it is working correctly ?? if it is only opening 75% then it may be fine most of the time and under higher load conditions be causing a problem .... removing a thermostat is not a hard job it can easily be done at home on the drive .... block / head tests require a garage and specialist tools so omitting it will cost less and be easier than checking parts which are less likely to fail such as the block .

Sorry Holmesie, I didn't mean it to sound like yours was a poor suggestion. It's a perfectly reasonable test to try.

Hi! Thanks a lot for your answers!

Is it possible to have a head gasket/block failure, without the car consuming any coolant at all, and no bubbles on the reservoir? I would have thought that if you have a head gasket failure, or a crack in the engine block, the problem should appear everywhere and not just on steep uphills, but, im not any expert on anything car related

Yes. I've seen cars that will do hundreds of miles whilst loosing almost none. Give the engine some real work to do and it can lose all the coolant in minutes.

I would...

Check the water pump - raise the engine rpm to about 2500rpm and check the coolant return flow to the reservoir - you should see a steady stream into the reservoir from the small pipe on the side.

Check that the radiator gets hot and the cooling fans work.

Do a pressure test

Do a block test

Sorry Holmesie, I didn't mean it to sound like yours was a poor suggestion. It's a perfectly reasonable test to try.

i know ... just saying .... anything is worth a shot to help some one cure a problem