I recently bought this Skoda. I had full service done on it 4 days ago and also the complete Thermostat Housing and the Pre Cat Lambda Sensor was changed.

Since last 2 days I have been having some trouble with the car. The exhaust is smokey. By smokey I mean it is impossible to drive beacuse of so much smoke which completely blinds the person behind me.

This only happens when the engine is hot around 90 degrees and smoke increases on higher RPM. When the car is cold it runs normal. So as long as the RPM doesn't go 2100 I am ok as the smoke is just visible but anything above that is a like a big black cloud. It feels like driving on choke all the time after the engine is hot.

While servicing, the garage did tell me to replace the Breather Pipes as they are ruptured. Can this be a potential cause of the problem?

The engine managment light hasn't gone on. I have VAG-COM but dont know what shoud I be checking for.

If anyone could guide me on how to resolve this. The MOT is due in 2 months.

I need to drive to work and without a car there's no other possible way to work.

Thanks in advance for any advice.

SS

PS: The clutch is also worn out and needs replacing, if this helps.

Is the smoke comming from the exhaust or could it be a burning clutch?

If the breather pipe is venting oil onto a hot exhaust you could be seeing that oil.

Is the car using much oil and is the smoke blue at all?

Did this only happen after the garage changed the parts, if so i would suggest you should pay them a visit as they may have caused this.

HTH, and i'm sure a petrol driver will eb along soon enough to help

piston rings or valve stem seals methinks!

I haven't checked if its coming from the exhaust or not. It does seem like coming out from the exhaust.

It smokes even when I rev the engine up in neutral so I am guessing it can't be the clutch burning (correct me if I am wrong).

This started after the thermostat was replaced as it was broken. Now when the engine gets upto optimum 90 degrees (as Skoda mentions) it starts giving out all that smoke. Its like even though the engine is hot but the ECU still thinks its cold.

The smoke doesn't look blue. I haven't noticed any change in fuel consumption. Although I did notice when the engine is hot and is smokey the throttle response is lower than usual and I felt some power loss as well. It all feels like driving on choke even when the engine is hot (Like in old motorbikes)

The smoke smells like a lot of HC residue in it.

I hope this helps. I cant drive this car at all with all this smoke.

Thank your for your help. Much appreciated.

piston rings or valve stem seals methinks!

Hello,

Thanks for the advice. Any ideas how much expense am I looking at if this is the problem.

PS: Check my previous reply please. See if it confirms your thoughts about this problem. Ta...

If the smoke is black the engine is running rich, if blue that is oil burning. You say it is black, get the VAG Com out and get it up to temperature and get into a measuring block where coolant temperature is displayed, if you know the engine is at 90C and the block says 20C the temperature sensor is likely to be the problem.

If the smoke is black the engine is running rich, if blue that is oil burning. You say it is black, get the VAG Com out and get it up to temperature and get into a measuring block where coolant temperature is displayed, if you know the engine is at 90C and the block says 20C the temperature sensor is likely to be the problem.

Hello,

Thanks for the reply. The dial on the dash reads it right, i still need to check it using VAG-COM.

yeah, reading your reply, i think it might be an over fueling problem, possibly the coolant temp sensor was damaged by being overheated

A stupid question I suppose :

Is engine coolan temperature sender and a thermostat two different things.

Which one actually does the job of reading the temprature output on the dash and to the ECU?

Is this true - If the dial reads the temperature right that doesn't mean that the temperature sender is sending the right signal to the ECU.

If the above is true, I would guess that when the thermostat wasn't working the ECU kept switching on the fan every now and then and hence I suppose the engine never got hot and that's what I always saw on the dial - very low temperature. Now that the thermostat is working, the engine gets hot but the ECU doesn't know right temperature although the dial on the dash does.

Thank you for your help.

Part No:

Engine Coolant Temperature Sender: 059 919 501 A

Thermostat: 050 121 113 C

Yes they are two different things and in differnt locations. Can't remember if the temperature sender is a 2 or 4 pin sender, if it is 4 pin, 2 are used for the gauge reading and the other 2 are for the ECU, which will control the fuelling, which means that the gauge and ECU can possibly get different readings. If these readings check out, have a look at the air filter and have alook at the readings for the air flow, showing too high and the ECU will put more fuel in.

The thermostat is mechanical and regulates the water flow to the radiator by means of expanding wax to open and return spring pressure to close it.

Yeah if MAF starts failing/covered in crud then it will mean the wire has a higher resitance and so will fool the car into thinking the wire is colder than it really is. Therefore the car will think it is getting more air than it really is and will nicely overfuel.

Do check your oil level and make sure it isn't going down, but from what you say i don't think you are burning oil.

Can't remember if the temperature sender is a 2 or 4 pin sender, if it is 4 pin, 2 are used for the gauge reading and the other 2 are for the ECU

Mine (TDi) was a 4 pin job, iirc. Infact it is still in the glove box, so I'll check later, and if I am wrong I'll edit this post!

Thank you all for your help.

I did check the Coolant Temperature Sender and it is 4 wire one.

When I replaced the Thermostat I was a bit over cautious and replaced evrything there i.e. the complete thermostat housing including the Coolant Temperature Sender (yes, i just realised that the Coolant Temperature Sender was changed as well as I found the old one on the housing).

As mentioned before the Pre Cat Lambda Sesnor was changed as well.

The car had a full service done as well 2 weeks ago.

Now here's all the observations made till date:

Engine Fault Codes Check (After Changing the Thermostat)

Code: 16502

Engine Coolant Temperature Circuit - G62

Signal Too High

Code: 17700

Map Controlled Engine Cooling Thermostat - F265

Open Circuit

Code: 16556

System Too Rich Off Idle, Bank 1

System Too Rich

Code: 17524

O2 Sensor Heater Circuit, Bank 1, Sensor 1

Open Circuit

After this I replaced the Pre Cat Lambda Sensor and had the ECU Reset for fault codes.

Now no faults. But:

When I measure block 4 I get these readings:

1: Temperature - 93 Degrees

2: Temperature - 21 Degrees

I dont know why there are two temperature readings in the same measurement block group 4. But 93 Degrees matches with what the dash board gauge says.

Please someone help me out. I am really frustrated now. Dont know what to do?

Thanks again everyone.

The bizzare thing with the 1.6 is it has a mappable thermostat and duel temp sensors. IIRC they are used to heat the block up faster by bypassing the cooling system in the head until the temp is up. If they have replaced the whole housing I think it comes with new sensors.

My feelings would be fix the breather hoses first, if these are split they can cause all sorts of issues as crankcase pressure isnt constant. Try running a modern engine with the oil cap off, they aint happy.

Hello Everyone,

I have just had my car checked and its now smokey even when its cold. The garage said the head gasket is gone.

I called the Skoda Authorised Service Garage and they said its really rare on an Octavia for a head gasket to go like that.

Please recommend. I have been given an estimate of

Hello Everyone,

I have just had my car checked and its now smokey even when its cold. The garage said the head gasket is gone.

I called the Skoda Authorised Service Garage and they said its really rare on an Octavia for a head gasket to go like that.

Please recommend. I have been given an estimate of £600 + VAT

First thing you can do to confirm this theory is to wait for the thing to cool down and then check the oil and coolant tank.

If you find any mayonaise in the oil there is a possibility that you could have a head gasket leak, however this stuff can form in the oil for other reason, such as frequent stop start driving and the car not getting up to temperature and having a nice long run.

If you find this mayonaise or oil in your coolant that is pretty much a cert for a blown head gasket of something similarly bad.

If neither of these symptoms appear then I would be looking at the colour of the smoke. Is it blue, (burning oil), black (excessive fueling) or white (even when the car has warmed up, which is usually water).

Also fairly obvious, but if a blown head gasket is causing lots of smoke, then you will be loosing coolant. If you are not I would definately seek a second opinion from a different garage.

What might be worth doing is having the fuel filter drained of water just incase you have had a bad batch of fuel.

Failing that ask another garage to check your car out and carry out a pressure test on the engine so that you have a second opinion.

Hope that Helps.

The smoke is white ... thick white smoke ... smells really bad

White smoke is usually water. Do you have to keep topping your coolant level up?

The smoke is white ... thick white smoke ... smells really bad

Check your oil, and coolant tank as described above.

As has been said by myself and others do you need to top up the coolant level on a fairly regular basis?

If so coolant is leaking into your engine which is usually from something like a head gasket etc.

hhello every1,

Thanks for all your help and advice. I have got the breather pipes changed but the problem still remains.

The garage will be opening the engine block today. I hope it will just be the head gasket or worse valve stem seal. I can't afford to get piston rings repaired or the a cracked block (i hope its not a cracked cylinder).

The problem still appears only when the engine is hot. I guess it can be a cracked block as well. The engine did pass the pressure test.

This is the worst time ever to be spending so much money. I thought Skoda Engines were good.

No worries ... lets see wot comes out next ...

I'll post the results when I get some ... for some1 who might face this problem in future.

Regards,

SS

hhello every1,

Thanks for all your help and advice. I have got the breather pipes changed but the problem still remains.

The garage will be opening the engine block today. I hope it will just be the head gasket or worse valve stem seal. I can't afford to get piston rings repaired or the a cracked block (i hope its not a cracked cylinder).

The problem still appears only when the engine is hot. I guess it can be a cracked block as well. The engine did pass the pressure test.

This is the worst time ever to be spending so much money. I thought Skoda Engines were good.

No worries ... lets see wot comes out next ...

I'll post the results when I get some ... for some1 who might face this problem in future.

Regards,

SS

Did you check the oil for mayonaise and the coolant tank for signs of water?

If so did you find either or were both clean.

I'd get the thermostat changed and also get the waterpump and a new cambelt done assuming thing has to come off anyway (can't think if it does).

there was mayonise in the oil tank ... but i was told it can be there because of making short journeys ... i cudn't tell if there was any oil in the coolant tank ... the oil tank was empty when the car was taken to the authorised garage ... it burnt all the oil ... (I was surprised to get a cheaper quote for repairs from an authorised garage. The local garage was charging almost the double)

the themostat is like 2 weeks old .. the belt is coming off so that will be replaced ... for the rest the garage said, it will replace depending on condition of the part ...

while checking the car .. another major fault was found ... the fuse box is melted .. apparantly the alternator is producing 55 amps and i was told it shouldn't do that ...

I really liked Skoda's ... dont know if i'll be recommending it to any1 anymore ... can be just me being unlucky with this one ..

First thing you can do to confirm this theory is to wait for the thing to cool down and then check the oil and coolant tank.

If you find any mayonaise in the oil there is a possibility that you could have a head gasket leak, however this stuff can form in the oil for other reason, such as frequent stop start driving and the car not getting up to temperature and having a nice long run.

If you find this mayonaise or oil in your coolant that is pretty much a cert for a blown head gasket of something similarly bad.

If neither of these symptoms appear then I would be looking at the colour of the smoke. Is it blue, (burning oil), black (excessive fueling) or white (even when the car has warmed up, which is usually water).

Also fairly obvious, but if a blown head gasket is causing lots of smoke, then you will be loosing coolant. If you are not I would definately seek a second opinion from a different garage.

What might be worth doing is having the fuel filter drained of water just incase you have had a bad batch of fuel.

Failing that ask another garage to check your car out and carry out a pressure test on the engine so that you have a second opinion.

Hope that Helps.

they did drain the fuel filter and the tank to make sure it wasn't bad fuel .. no luck ..

this already is my second opinion from an authorised garage ... they really did try everything b4 opening the block :-(

If you have no oil and there is mayo in the tank, then yeah it certainly sounds like you lost a head gasket. Sorry to hear this, had the car overheated before all of this at all?

I think i said earlier mayo could be from short journeys, but yeah either way not ideal.

I would say that if you have the cambelt off and the coolant out then chan ge the water pump as the impellor is plastic and they are already removing all coolant. That plus you have no idea what the sludge in the coolant will have done to affect the water pump and it is only an extra £25 (exchange part) to have a new one fitted.

Tbh i think you have just had some bad luck, but i hope it all gets fixed and doesn't work out too expensive.

Hello,

I just got news from the garage. The Oil Ring is fused to the Piston. They have taken the whole engine apart.

Now what all things would be good to be replaced while they are on it?

Thanks

SS