I've posted a question about this several times - with lots of helpful advice. But I'm still stuck.

It's a W reg (2000) Fabia 1.4 MPi with 65,000 on the clock. Getting bad economy. For example this week I've spent £25 (about 29 litres) and have only managed approx 150 miles. When I bought the car in June I was getting more like 240 for the same amount of fuel

Since the summer I was smelling petrol in the car. I thought it was tied up with the the fuel economy issue. Our mechanic spotted that the oil cap wasn't fitting correctly onto the engine (because of the badly fitting big plastic engine cover). He sorted it and the smell has gone.

I hoped that would be affecting the fuel economy because of too much air getting into the engine - but it hasn't. It's just as terrible as ever.

The oil was last changed in May

The MAP sensor was changed in April

The temperature sensor was changed in May

The air filter was changed in May (I've recently checked it and it is fine)

Tyre pressures are fine

The engine idles at 800 revs - which I think is about right

The engine does sound a bit rough and is noisy. I think this will be the timing chain. I have heard that this could be affecting the fuel economy - but it would be an expensive job and I would like to try and rule out everything else first.

On Friday we are due to be driving down to the Isle of Wight from Leeds! So this could work out to be quite an expensive journey. If there is a few things I could try doing before friday that aren't too expensive I will give them a go.

Can anyone suggest what I should do!!!!! Would really appreciate it.

Out of interest - how much would you expect to pay for the timing chain to be sorted?

Cheers. Ian

Well, for starters, that economy does seem a bit bad even for 1.4MPi. But if you're driving in urban areas and you have lots of cold starts and you dont get your engine warm enough then it's possible to have such a low economy. Though, I highly doubt you're driving like that.

Check the plugs, they might be old and gooey and that reduces the economy somewhat. Also, you might want to check if your brakes are not binding. And whats more, check your fuel tank for holes or such

The chain doesn't have much to do with economy. I changed mine in summer, noticed a bit more grunt from the engine but no economy gain.

get some redex or something in the fuel and give it a good welly for 100 miles to get the stuff through the system, should clear any crap within the system and probably help. i think personally after seeing what you have done that it just needs a good quick thrash to clear the crap thats accumulated within the system.

Make sure the brakes aren't binding. You need to have the engine management system scanned for faults and also have an emmision test carried out to ensure the lamda sensor is doing it's job correctly. Any exhaust blows? I would suspect that whatever is causing the engine to sound rough will be causing the poor fuel economy.

Thanks for the replies - that gives me some ideas to try. Just to give some more info in reply to what you've all said...

The driving I do over a week is a real mixture - half an hour each day on a motorway, in and around town, 40mph country roads...

I don't notice that I'm having to ever particularly press hard on the throttle - I'm quite gentle with it and generally just feather it

The plugs aren't more than 10 months old and when I had our mechanic check it over a couple of weeks ago they were really clean. Also he checked the pressure and he said he was getting really good results.

I did a bottle of redex a couple of weeks ago - no noticeable difference, although I didn't give it a long run. Is this something others recommend?

I also think the rough sounding engine is causing the bad economy - although its sounded bad since I got it and when I bought it the economy was much better. Maybe it's just got worse. Someone told me that faulty fuel injectors could cause to much fuel to be going into the engine making it sound a bit rough. If this was the case would I not notice the idling engine speed to be higher than it should (it's currently about 800 and I think that's about right?)

Re binding brakes. How would I know this is what's happening? I have noticed in the past couple of days a rough grinding noise (I think from the back) when I apply the brakes but also when driving at slow speeds I can hear it (not a constant noise - it more like it's rubbing at the same point every time the wheel turns. I don't know much about car brakes - but it's remind me when the brake block on my bicycle would rub the rim of the wheel - I guess it's the same principle?). Anyway... I just thought this would be dirt that's got in because it's winter.

At the moment I'm thinking that I will try changing the lambda sensor and the fuel injector. What do others think? Are they expensive jobs and would I be able to do them myself?

Thanks

Ian

Take it to get the fault codes read ....you may be surprised and it could tell you what's wrong

Yeah - I am wondering whether this is really what I need to do - but the Skoda garages charges about £50 just to do that!

Does anyone have the equipment who could do it for me?! Thanks everyone

I did a bottle of redex a couple of weeks ago - no noticeable difference, although I didn't give it a long run. Is this something others recommend?

Ian

Basically what ive done on cars when they perform badly is let the tank get down to halfway, add a whole bottle of redex then go for a drive for about an hour with revs up quite high to clear the system. whilst on the drive put a bit of redex into each plug hole and leave running on the drive as it goes through (this will smoke for a short time) but this should then clean the system and decoke it. by the time you get down to red and refill you should notice a crispier response and better mpg.

My sister had bad economy on her MX5, it turned out that one of the wheels brakes were binding. Depending on how bad, if it all it should be easy to check.

Go for a drive, being relativley light on the brakes and then park up. Walk around the car and touch each wheel in turn, (you need to take the hubcaps off), and if you find one hotter than the opposite side you have found your sticking brake.

whilst on the drive put a bit of redex into each plug hole and leave running on the drive as it goes through (this will smoke for a short time) but this should then clean the system and decoke it.

Thanks for the advice re redex smstext - can you describe to me a bit more about this bit of the procedure for me? It sounds like what you're saying is put the redex in to a half a tank [the last bottle of redex I had said on instructions there wa enough for two tanks - you are saying just put the whole lot in anyway?] and then, whilst out giving it a good run with high revs [what are high revs by the way? About 3000? higher than that?], pull up somewhere, take engine off and plugs out and put a bit of redex into each hole [how much redex? about a teaspoon?], replace the spark plugs and then leave the car running for a few mins while stationary while the redex burns through?

Is this what you mean? Thanks - I might just find time to give this a go tomorrow. Cheers. Ian

The fuel has to be going somewhere. The MPG seems very low.

Can you smell petrol at the exhaust?

Do you have a petrol leak?

When you release the handbrake, is there tension as you lower the handle? When cruising, do you have to use more throttle?

Check that the charcoal canister (and valve) and connections are OK.

Check the fuel filler cap is a good seal.

Check the fuel return hose for cracks.

Hi,

My Fabia 1.4 mpi has the same issue its an X reg. I've only had it for a couple of months so im not sure if it was any better before, but bit of a nightmare at the moment with this high consumption

i've read this thread and its very useful, Briskoda are doing a brilliant job i think.

anyway back to the point, i got it somewhat serviced last week; changed the oil filter, replaced the oil all spark plugs replaced etc but the economy has not improved much:( i dont think its anything to do with my driving, because my gear changes are quick and I dont rev a lot above 2000, try to keep it below that

i might try the redex therapy and get back

but just wondering if you've managed to improve it itgoodson?

Hi muaaztahir. I've just returned home with the new thermostat body - cost £37.33 (I think) from Skoda dealership. I'm going to have a bash at fitting it this evening. Once I've had a day or so with it on (if I get it on) I'll get back on here and let you know what's going on with it. I've read absolutely loads, especially this post http://briskoda.net/fabia-i/fabia-thermostat/93666/ that seems to really relate to my situation, and I'm and becoming more and more confident the thermostat is the problem.

You're right - the guys here on Briskoda are really helpful.

Ok I read it and I myself can relate to the problem very much, the temp stays low even after doing 12-15 miles! its bad timing to judge it I guess because most of the time my car is frozen in ice anyway but still the temp should go up after 10 miles of driving?

so yeah let me know how hard the procedure was and whether it helped? sorry im using you as a guinea pig lol

That's fine. It's good (in a strange way!) to know others have had the some problem. Gives me some hope of getting it sorted without too much expense!

hi muaaztahir. i've had a go at changing it. and its not that hard! i would certainly recommend having a go. Ap0gee has given loads of good advice - just do a search. He recommends to empty all the coolant from the system, and I'm sure it is the best way. But I got away without doing that - I just a washing up bowl under the car to catch what came out (in the end i threw all this down the drain anyway)

Some tips:

i. i didnt have mole grips - just a small ordinary pair of pliers. this meant i couldnt get the hose clip bands back on. thankfully i had bought some other hose clips that tighten with a screw driver.

ii. The switch with wires coming out is v difficult to come - persevere

iii. washing up bucket under the engine to catch the water

iv. buy yourself a bottle of coolant anti-freeze for when you top up the level

v. you will need a simple socket set (with an extension) to get the bolts off the part.

apart from that just take your time and be methodical. the part i got from skoda cost about £33 plus VAT, and it took me about an hour or so.

Will update in a few days or a week or so to update on the fuel economy.

Ian

That sounds very encouraging, thanks for the advice! please do let us know if it solves the issue, i really hope it does!

In the meanwhile i'll try and get hold of the part myself

Update today - car feels like its running a whole lot better. Will have to wait to see how the economy goes.

But, stupid rubbish w-reg Fabia, no sooner do I ever get one thing fixed something else goes wrong: driving to work this morning and the speedometer needle stopped working. I was looking at it, doing a steady 30mph, and it just dropped to the bottom. Weird! Happened a couple of times - each time I gave it a bash on the dash and it started again. Anyone any advice?

Update today - car feels like its running a whole lot better. Will have to wait to see how the economy goes.

But, stupid rubbish w-reg Fabia, no sooner do I ever get one thing fixed something else goes wrong: driving to work this morning and the speedometer needle stopped working. I was looking at it, doing a steady 30mph, and it just dropped to the bottom. Weird! Happened a couple of times - each time I gave it a bash on the dash and it started again. Anyone any advice?

Check that the speedo cable is securely fitted to the back of the clocks and the other end too!!

I've posted a question about this several times - with lots of helpful advice. But I'm still stuck.

It's a W reg (2000) Fabia 1.4 MPi with 65,000 on the clock. Getting bad economy. For example this week I've spent £25 (about 29 litres) and have only managed approx 150 miles. When I bought the car in June I was getting more like 240 for the same amount of fuel

Since the summer I was smelling petrol in the car. I thought it was tied up with the the fuel economy issue. Our mechanic spotted that the oil cap wasn't fitting correctly onto the engine (because of the badly fitting big plastic engine cover). He sorted it and the smell has gone.

I hoped that would be affecting the fuel economy because of too much air getting into the engine - but it hasn't. It's just as terrible as ever.

The oil was last changed in May

The MAP sensor was changed in April

The temperature sensor was changed in May

The air filter was changed in May (I've recently checked it and it is fine)

Tyre pressures are fine

The engine idles at 800 revs - which I think is about right

The engine does sound a bit rough and is noisy. I think this will be the timing chain. I have heard that this could be affecting the fuel economy - but it would be an expensive job and I would like to try and rule out everything else first.

On Friday we are due to be driving down to the Isle of Wight from Leeds! So this could work out to be quite an expensive journey. If there is a few things I could try doing before friday that aren't too expensive I will give them a go.

Can anyone suggest what I should do!!!!! Would really appreciate it.

Out of interest - how much would you expect to pay for the timing chain to be sorted?

Cheers. Ian

If the economy doesn't improve after fitting the stat I would locate the fuel filter and make sure that it's not seeping under pressure (pipes) and sometimes these can rot on the joins which will also leak under pressure. - good luck!

Thanks for both bits of advice loco. I haven't had chance to check the economy properly yet - will do at next fill up (which will be tomorrow). But it feels like its running better. But I may yet need your advice (hope not though)

Speedo working ok at the mo - I don't really know how to check the cables. Will have to investigate. Cheers

Possibly a Dodgey Lambda Probe (02 Sensor) Not faulty enough to throw a Check Engine, But bad enough to give you Crap Economy by not reading the Oxygen content properly & supplying the incorrect amount of fuel.

Cheers

Dean

Have either of you changed the coolant temperature sensor? If the temp gauge is showing low after 10 miles of driving then in my opinion you have a fault there. If it is reading low then the car could be stuck in a cold start mode where it will supply (much) more fuel than it needs which could explain both your poor running and terrible MPG.

Hiya - changed the whole thermostat body, including the sensor, and I think it has made all the difference. Cheers!