Hi everyone

I have a set of symptoms, perhaps they are related, and I hope someone can give me some pointers and perhaps a list in order of order of cheapest first on what to try!

Fabia W Reg (2000) 1.4MPi

Very bad fuel economy. It was about 30-33mpg, now it's dropped to about 22-24mpg in the last month

Lack of power/pull

Rattling engine noises (I think associated with the timing chain)

Loses water rather quickly - have to top up every 6 weeks or so.

I have checked tyre pressures re. the fuel economy, but they were only about 2psi under on each tyre.

I have tried 97 octane fuel - no difference!

Last service was in May - although previous owner had that done

Checked the air filter. It doesn't look very dirty - a grey colour in the centre rather than dark grey or black

I wondering whether I should just get another service done - although that would not be nice knowing what that Skoda suggest 20,000 mile service interval!

Any pointers would be most helpfuk. Have read about cleaning throttle body, but don't know how to do that... any advice?

Is the water leaking out? I suspect you may have a blown head gasket if not.

Do others suspect a blown head gasket? I had that happen on our previous car, a vauxhall astra, and this doesn't seem to be like this - our Fabia is quite driveable, the engine noise is not excessive, just rattling as if the chain was worn

Hmm Maybe a Lambda sensor? Coil Pack?

Coil packs are quite common, so may well be worth checking out..

Does the engine management light (or emissions light) come on at all?

The emissions light will come on if there's a "decrease in quality of exhaust gases"...

This basically means that there is a misfire, or something going wrong!

Could be burning oil, maybe water...

Ideally you need to get it plugged into VAG COM to see what comes up on the fault codes!

If you're local I might well be able to do that for you

x

normally head gasket gone can lead to contamination in the oil, is there milky deposit on the dipstick or the oil filler cap? Poor consumption could be Coil packs/MAF/Lambda probe/Throttle reset? engine light doesn't always come on if the Lambda is lazy(old). throttle body cleaning normally relates to rough idle/running rather than just poor mpg.lack of power on the tdis is often down to the MAF. try running with the MAF unplugged, it will force the ECU to use a default set of values so if the car runs better with it unplugged you know you have a faulty MAF. HTH

OK, let's not get carried away with head gaskets - topping up every 6 weeks isn't too bad. I admit, you shouldn't have to top up at all, but our dads would have put up with that no worries! As has been mentioned, a blown HG will cause mayonnaise under the filler cap (water into oil), or grot in the expansion tank (oil into water). In the case of the Fabia, a likely source is the seal round the radiator fan switch - not difficult to replace. As for the poor fuel economy, try these:

The filter is a good starting point, and I did a guide for the coolant temperature sensor, here. HTH

Thanks for all these replies, very helpful

The MAP sensor was changed in April, and the Lambda sensor at some point this year too.

Thank for the list of possible things: I think I am just going to have to take it to our garage!

DubNutty - I am in West Yorkshire - is that local to you?

I really would have a go at the coolant temp sensor yourself: it's a piece of cake on the 1.4 MPi - fifteen minute job, and most of that's getting the engine cover off and back on again! It's a known cause of poor running, and they're one of those parts that go eventually anyway (probably about 4 or 5 year life), so if it doesn't fix it, at least you'll have warded off that particular 'timebomb' for a few years and saved yourself the labour and extras (a garage will drain and refill your coolant, which really isn't necessary!) Plus they'll just follow that list I posted previously! ( )

It won't be the coilpacks, as the 1.4 MPi has the old-style 'external' coils, as can be seen at the bottom of the second pic in the how-to thread I linked to above. One thing that may be nothing more than unsubstantiated rumour but is worth a try on the grounds that it won't cost you anything, is to leave the ignition in the 'lamp test' position for a couple of minutes (i.e. ignition on, but engine not started). Legend has it, this will reset the ECU to factory settings which may clear any 'mis-learned' ECU coding...

I agree about the coolant temp sensor being an easy job, even i managed it lol

thanks to Apogees excellent guide of course.

Thanks a lot or this _ i have a feeling the engine temp sensor was changed a few months before I bought it in June. I'll have a check in the log book.

I've just checked the oil level in the car. I should have done this already. The level was quite low - near the min. mark. Could this be a reason for decreased fuel economy? Or power issues? I've topped it up anyway

loss of coolant is likely to be a leak from the thermo switch on the passenger side of the radiator.

The rattling timing chain could be the cause of the lack of performance, the vibrations setting off the knock sensor and the ECU retarding the ignition timing. The drop in fuel economy could be a side effect of the drop in performance, you are using the accelerator more to try and make up for it.

When the Fabia first came out and we were doing head gaskets on them, the only clue as to whether they had gone was a slight oil residue in the expansion tank.

Another symptom I've noticed (to go alongside lack of power, rattling noise (I suspect the chain), loss of water, and high fuel consumption): I can smell petrol coming into the cabin, especially when idling after a few minutes driving.

Does this help suggest what might be the problem?

I've dug out the log book and it's had the following changed between April and June this year:

Temperature sensor

MAP sensor

And something the receipt calls a 'Fram Filter' - I'm not sure what this will be?

Does this help pin point what could be wrong?

Fram is a manufacturer so could be anything - most likely an oil fiter.

www.fram.com

I'd guess at an air filter tbh since it doesn't state an oil change at the same time

I'd check the fuel pump housing (under the rear seat), i've had replaced 2

in the last few months.

You might want to ask skoda if your car could be affected by the piston ring issue that affected some 1.4 engines.

There is a good chance your one isn't but best to ask somebody who would know before spending good money on other things.

Can anyone tell me how easy it would be to change the lambda sensor? And can someone tell me how it would affect fuel economy? Thanks!

Can anyone tell me how easy it would be to change the lambda sensor? And can someone tell me how it would affect fuel economy? Thanks!

Lambda sensor is the main piece of electronics that tells your car how much fuel to put in cylinders. If that's buggered, then your engine is buggered.

I wondering whether I should just get another service done - although that would not be nice knowing what that Skoda suggest 20,000 mile service interval!

I dont think Skoda have a 20k miles before services. I think they need servicing every 10/12k miles.