Fabia 1.4 16v experiences and tips

[PToledo]

Hi everybody,

Long time since I don't post here. I own a Fabia 1.4 16v 100HP AUB engine and I must say it is a picky engine, any small abnormal data from the sensors and the ECU will trigger some CEL errors. I believe problem is VW tried to make an early Euro IV engine from an old design just adding a lot of electronics and tighting too far the antipolution margins.

From some years now I took a lot of knowledge from this website trying to solve my own problems with this car and I think is fair to share my own experiences, hope this will be useful for anyone who owns this this engine (or similar):

*Air intake*

- Clean regularly all the carbon and gunk residues from throttle body, the intake manifold and the EGR end. I do it every service/oil change (about 15K km.) with some carb cleaner spray and the engine off. It is a very easy job and will solve a lot of problems. I tried to take the MAP sensor out and have it cleaned it but it seems a bit difficult as the timing belt guards prevent access to the second bolt.

Anyway it looks like spraying the carb cleaner inside the intake manifold will somewhat clean it. Now I have a rock solid idle.

- Check for air leaks at the filter airbox (check the silicon gasket is in place), the exhaust, the rubber PCV hose from the crankcase ventilation box to the filter box, the rubber hose from the carbon filter and the rubber gasket under the throttle body that may be deteriorated and let unmetered air in.

- Check the hot air flap at the filter airbox. In my case the thermostat that closes the flap didn't work so my engine always ran on hot air, this caused me some annoying knocking. I just removed the flap and blocked the hot air intake to the engine.

- Check and clean blockings in the rubber hose from the carbon filter and the valve (makes a clicking sound on idle). In my engine it was connected to the intake manifold on a metal L that was blocked with gunk coming from the EGR, this is used mainly when the car idles so cleaning it will smooth your revs at idle. Also check and clean blockings in the PCV rubber hose from the crankcase ventilation box behind the engine (I just spray some carb cleaner down this hose just before oil change).

- Check the rubber gaskets at the oil filler cap and below the "oil funnel" in the overhead cover the cap is closing (the part # is the same for them both). Mine where almost disintegrated, I think they can cause oil and pressure losses from the crankcase.

*Ingition System*

- Check the ignition coils for cracks. Mine had a severe crack in the middle, I read some people are repairing them with epoxy resin but I just replaced it with a Bosch aftermarket part (about 70€).

- Check the connections at ignition coils (just one in my engine) and at the ignition leads for oxidation. Mine had some kind of light green oxidation, so I did a light sanding and cleaning of the terminals with an electrical contact cleaner product. Testing the resistance of the coil and the leads with a multimeter is advisable too.

- Check the spark plugs are tight in place, mine get a bit loose after 20000 km , that is when I get them out and check their condition (they must light grey/brown with no oil). Replace them every 50000km/60000km.

*Oil Tips*

- Oil consumption in this engine is a bit high compared with other engines, it can be caused by PCV blocking, the engine running too hot or lean. In my case I got an acceptable consumption (about 200 ml. each 2000 km) and don't think it will ever be lower than that so I will have to live with it.

- Always get a GOOD SYNTHETIC oil, 5w40 grade it's fine with me, 10w40 did not make a difference for me in consumption and left far more residues, 5w30 and 0w40 increased the oil consumption. Get an oil with at least VW502.00 homologation, after some testing I prefer to use mid-saps oils (ACEA C3 alongside with the VW502.00, Total Quartz Ineo MC3 5W40 right now), as they leave less residue in the EGR and in the intake and it is easier to remove. I also believe they allow a longer life for the catalytic converter and the O2 sensor, but this is just an speculation.

- If you do a lot of short trips (like I do) with the engine cold then oil consumption will be high, no matter what you do. In this situation is advisable to shorten oil change intervals to 10000km.

- If you have been using mineral oil or it is a second hand car and not correctly serviced (this was my own case) as this engine is prone to carbon build up and some consecutive quality oil changes can clean some carbon out, this may mitigate oil consumption. I read engine flushes may work too but I can not recommend flush additives as I did not try them myself.

*Clutch and Gearbox*

- Got some problems with the clutch bitting point being too low. Changing the brake fluid and bleeding the slave cylinder helped a bit but this did not fully solved the problem, real problem was the hose taking the fluid from the reservoir to the master cylinder was loose and let the air enter in the circuit. A simple plastic zip tie tightening the hose to the reservoir solved the problem.

- Also the clutch made some rattling noise when cold, pressing the pedal made the the noise dissapear. Though it was some clutch bearing, surprisingly a gearbox oil change solved this and made gear handling a lot smoother.

*General Tips*

- Always go for the easiest solution first: Air/fuel filters, clogged intake, spark plugs, loose electrical connections, faulty battery ...etc. Basically many of the faults have an electrical/electronic cause.

- Make sure the part you are replacing is really faulty and in doubt ask first for a second opinion: Damaged ECUs are not usual no matter how much dealers insist and replace a faulty O2 sensor is half a hour. In my case I got some EGR errors but the problem was the EGR end was clogged up, I am sure the workshop would have it changed.

- Go for OEM parts or high quality aftermarket parts (Bosch, Mann, NGK..etc). I got my new O2 Sensor from a NGK seller in eBay, plug and play and half price (120€ vs 250€ at dealers).

- Get a (cheap) VAG cable and use it, not only for resetting errors but for adapting and monitoring. I hunted some sporadic misfire faults at Cylinder 4 monitoring the engine while driving.

- Get the workshop manuals in PDF for your engine. Google is your friend.

- When in doubt and just for peace of mind, clean the electrical connections with electrical contact cleaner spray and let dry before reconnecting.

- The 1.4 16v is a very easy engine to maintain, plenty of room to work and almost everything is reachable from above. Making the repairs yourself can save you a lot of money and will give you great satisfaction.

*Things To Do*

Some thing I would like to do sometime.

- Visit the dealers Workshop and ask for a ECU software update (if exists and not too expesive).

- Undo the starter and clean it to get rid of the starting grinding noise. It seems is a common problem with VAG cars and starters.

Well, I think this is all, hope this will be useful for someone.

[tuscan440]

Great advice, my gf got a Fabia 1.4 16v last year and it hasn't exactly been plain sailing but then I knew there would be things to sort on it as that was why we we paid less for it. I am planning a major service in a couple months time for it and so will use this as a guide. The inlet manifold is definitely coming off, because if the state of the EGR was anything to go by then it will be chock full of gunk! The vehicle still stalls randomly and struggles a bit when pulling away so I looking at what it might be. I am about to replace the fuel filter and I am tempted to replace the air flow senor although I would like to think this was all a sypmtom of gunk in the mainfold.

[rum4mo]

Yes, good points, and most will apply to the "B" series of engines,

"*Things To Do* Some thing I would like to do sometime.

- Visit the dealers Workshop and ask for a ECU software update (if exists and not too expesive)."

Yes, indeed, I see that Seat claim to do this at every service, in my case, VW, they don't seem to know too much about S/W updating - my wife's BBY engine in a Polo throws out "bank 2 exhaust cam timing" errors once every month in winter - for the past 8 or so years!

I tend to find that it is the throttle body end of the EGR valve pipe that gets clogged up.

Edited 13 March, 2013 by rum4mo

[PToledo]

I am about to replace the fuel filter and I am tempted to replace the air flow senor although I would like to think this was all a sypmtom of gunk in the mainfold.

@tuscan440 : Try cleaning the sensor first, and then replace if that does not work. I found cleaning it makes a great difference, although I only sprayed the whole intake manifold as I couldn't figure out how to remove the sensor without removing the back guard of the timing belt.

Yes, good points, and most will apply to the "B" series of engines,

"*Things To Do* Some thing I would like to do sometime.

- Visit the dealers Workshop and ask for a ECU software update (if exists and not too expesive)."

Yes, indeed, I see that Seat claim to do this at every service, in my case, VW, they don't seem to know too much about S/W updating - my wife's BBY engine in a Polo throws out "bank 2 exhaust cam timing" errors once every month in winter - for the past 8 or so years!

I tend to find that it is the throttle body end of the EGR valve pipe that gets clogged up.

This is funny because bank 2 errors only apply to engines with 6 or more cylinders, this ECU tends to throw some funny errors now and then. Mine throwed some unusual O2 sensor voltage errors that turned out to be a leak in the air filter box.

[no1joe]

You dont, by any chance, know about a tapping noise from the engine do you? Ive got the exact same engine as you, but i have a horrible sort of tapping noise. Its there on idle, still there when engine is hot, and seems to get worse when underload - certainly when accelerating. :/

[hap123ciu]

I would also mention the use of Super unleaded 98 RON for maximum power and reliability.

[sepulchrave]

- Check for air leaks at the filter airbox (check the silicon gasket is in place), the exhaust, the rubber PCV hose from the crankcase ventilation box to the filter box, the rubber hose from the carbon filter and the rubber gasket under the throttle body that may be deteriorated and let unmetered air in.

There is no airflow metering on this engine, it's all done from the MAP sensor so any air leaks on the high pressure side of the throttle butterfly will not affect the running at all.

Other than this the information here is very good, don't forget the ECU temperature sensor and EGR valve, they age badly giving false readings and usually need replacing.

[BlueSilver]

Great post, very useful. I also concur re decent fuel. The best I've ever used is Shell V-Power. For me, it really worked, engine was more eager and accelerated more crisply. Fuel economy was not better but no worse that supermarket stuff. I've also had the EGR light on the dash come on. This however can cure it self after a few runs under varying conditions, but suggests an underlying issue. Also had the throttle body cleaned out as this was full of gunk! Thanks PToledo

[AaronMountford1990]

Good stuff, i have a 1.4 16v elegance 100bhp, only faults i have noticed with mine is 4th gear judders a lot dependant on how you press the accelerator (not all the time, just most...) it seems to be pinking terribly and the car itself pulls left which i think is a steering angle sensor!

 

Good times hey !

 

Azza

Edited 31 July, 2013 by AaronMountford1990

[fabdavrav]

Thankfully I've had my X plate from new.....................I knew about the development of the engine so always ran on Mobil1 0w40 and v-power/nitro/optimax. whatever they hell they call it.................the engine was designed to run at it's best on 98ron which is why usually has the 98ron in bigger writing in the fuel filler cap!

 

Thankfully I've not had the problems that second hand cars with this engine have (due to bad petrol & oil regimes) .....now it'll probably throw a strop!

 

if you look at my sig below you'll see I run a few mods as well!!.............

[AaronMountford1990]

I'm on the v power now, and yeah. Just a few mods haha!! recommend any as a start for mine?

[PToledo]

Little update..

 

Got some occasional misfiring at cylinder 4. After much testing with a voltmeter turned out to be the 4th ignition lead had an internal crack so it failed when installed in some specific position and specially on low revs.

A new set of black NGK ignition leads solved the missfire and the car now feels much more smooth and revvy.

 

Moral is check your ignition leads if your car is misfiring.

Edited 7 July, 2014 by PToledo

[JoeChamberlain]

Yes, this is an old thread. But was an excellent read for me. Especially as I'm completely new to driving and am looking to remove the inlet manifold soon to give it a clean.

[sepulchrave]

Little update..

 

Got some occasional misfiring at cylinder 4. After much testing with a voltmeter turned out to be the 4th ignition lead had an internal crack so it failed when installed in some specific position and specially on low revs.

A new set of black NGK ignition leads solved the missfire and the car now feels much more smooth and revvy.

 

Moral is check your ignition leads if your car is misfiring.

 

I change plugs and leads every two years now and the coilpack after four years because this engine eats 'em alive.

[SLIPKNOT8988]

Hello I want to know why in the Haynes manual it says that you cannot dismantle the bottom end of a 1.4 16v AUB. Thank you

[sepulchrave]

5 hours ago, SLIPKNOT8988 said:

Hello I want to know why in the Haynes manual it says that you cannot dismantle the bottom end of a 1.4 16v AUB. Thank you

 

You can dismantle it but you can't rebuild it because the block cannot be rebored due to the cast-in steel dry liners.