Cambelt change and decreased mpg

[SlowTDI]

Hi all,

I had a search and find a few similar threads but with different engines.

I have a 54 plate fabia 1.4 tdi 3 cylinder and just had the cambelt changed, with the water pump and tensioners etc. All using genuine parts where available.

My concern is the fuel economy, it's dropped quite a bit. I do 600 miles a week, pretty much all motorway and have averaged according to fuelly, 67mpg. Since the belt change that is dropping to barely 52 mpg. I used to be able to get 600 miles ish to a fill up, now its 480 ish.

I'm not familiar with the engine so i don't know if it can be adjusted like some of the 1.9tdi's or if it's ecu based.

The other thing different is it starts instantly instead of spinning over once or twice first, then runs like a bag of crap for a few seconds.

Sounds like the timing isn't right to me. Anyone got any ideas or details of how to sort the timing?

I want my mpg back

Any help greatly appreciated.

Baz

[sepulchrave]

The timing definitely isn't right, take it back and tell them to sort it out.

[SKYHAWK]

take it back to garage and say what you have said above

[KenONeill]

The timing definitely isn't right, take it back and tell them to sort it out.

3rded.

[KeithCheetham]

 Done the belt and waterpump on my 56 plate 1.4 TDI this weekend. When set using the correct tools on the crank pulley and camshaft pin, the 3 bolts in the vernier pulley ended at one end of the slots, so assumed that given the length of the slots the pulley was just rotated another tooth on the belt, but still OK. Runs with no problem, power (what there is as its a 70BHP model) appears the same but my readout and average economy are also massively less than before. I know there are some triggers, but not sure if they are on the vernier or camshaft, or what they read.

 Will re-set next weekend and report back - let me know how you get on slow.

[mogwye]

After changing the Cambelt you need to re-set the Torsion Value with VCDS as this link shows http://www.myturbodiesel.com/wiki/camshaft-timing-torsion-value-adjustment-on-vw-and-audi-pd-tdi-engines/ then do an ECU reset, switch EVERTHING OFF, disconnect the battery for 30 minutes and without touching any pedals or switches, start up and leave to idle for 30 minutes. then see the difference.

 

DB

[mogwye]

For some obscure reason I cannot edit my own post above.

 

Good Tip - With a few quick clicks of the ignition switch, bring the bent tabs on the edge of the camshaft timing pulley to about a 2.0 o'clock position, stick a strip of masking tape to the vertical black plastic backplate and mark where the nearest Tab is, so that when attempting to make an infinitesimal minute adjustment you can gauge how much you have moved the camshaft, take your time it only needs to be the thickness of a cigarette paper that makes such a difference.

 

DB

[KeithCheetham]

 Will do a torsion value check this weekend, but happy to report that it appears to have settled down and is giving previous economy. Can only assume that reason for apparent error is that the battery was disconnected for about 20 hours, only been a few hours previously. As an aside, the water pump that I took off was stamped 06 and had VAG branding data cast into it, so assume it was the original - with plastic impeller - and had done 160K miles. Fitted Wanli S-1086 Winter Challenger tyres on front axle, the noise is horrendous, just hope the grip is worth it.

[SlowTDI]

Hi guys

Apologies for delay in reply.

Thanks for the tips, i think i need to find somewhere with the correct software/hardware to reset the torsion value as the garage didn't realise it needed it. Nor did i though :(

I will have a hunt and report back. 2 tanks of diesel later its still poor mpg so need to get it sorted ASAP.

Cheers

[KeithCheetham]

 Happy to report that torsional check is showing reading that fluctuates between 0.0 and 0.6 (either 1 or the other, not wandering between the 2 values), economy is as good as before so appears that the setting tools were used correctly and that the screws being aligned with almost the end of the cam pulley slots has no detrement, and that as suspected the belt is probably just misplaced 1 tooth in the pulley with the correction being with the pulleys relative position on the cam.

[billy2981]

Great info cheers.

Take it this will work on a vrs too?

Gonna have a play over new year

[SlowTDI]

I still haven't had time due to work to get mine sorted. The mpg is slowly getting worse so it needs looking at.

I'm half tempted to buy the cable and software myself.

[iiPaul]

After changing the Cambelt you need to re-set the Torsion Value with VCDS as this link shows http://www.myturbodiesel.com/wiki/camshaft-timing-torsion-value-adjustment-on-vw-and-audi-pd-tdi-engines/ then do an ECU reset, switch EVERTHING OFF, disconnect the battery for 30 minutes and without touching any pedals or switches, start up and leave to idle for 30 minutes. then see the difference.

DB

Does this work on a vrs?

[iiPaul]

Just read the guide

[billy2981]

Well cheers for the links and info.

 

After doing my cam belt I had a huge drop in mpg and the car ran like poo.  I adjusted it using vcds from this:

 

 

to -1.0 which wasn't right still but a lot better. That was just using the tool as the first time I did it the tool didn't fit right into the crank sprocket as I was trying to fit it on from the top when I should of been sliding it in.  DOH

 

I have been running the car like that as I have not had time to tweek it until yesterday.

 

Now after reading and playing I have got it to:

 

 

Is the Idle injection time something that needs attention? Ive tried playing but this is the smoothest start I can get.

 

Seems ok, Ill find out if its sorted the MPG out this next few days going to and from work.  Then Ill be fitting a heap of stuff to get it back to fighting fit again as its been a bit neglected over the last year with only oil and filter changes done every 6-8k. New engine mounts and complete new shocks and springs inc fittings to go on too before MOT.

[vindaloo]

I still haven't had time due to work to get mine sorted. The mpg is slowly getting worse so it needs looking at.

I'm half tempted to buy the cable and software myself.

 

Ideally, you'd measure it before and after but you don't need to do it that way...

 

http://www.autospeed.com/cms/article.html?&A=112521

 

J.

[faboka vrs]

VCDS lite interface is £10 of eBay. You can then download the VCDS lite demo from Ross tech.

[billy2981]

I got my old vag com 401 iirc licence changed over to the vcds lite as it was free seen as id payed before and for what i need it for it seems to work ok.

Are the readings right tho?

Or will i have a problem?

[KeithCheetham]

There appear to be slightly different optimal values for different variants (power outputs) of these engines. I would think that 1 degree is acceptable, but slight tweaks may improve - or degrade - the performance. How does it "feel" to drive compared to previous seat of the pants feeling. As said above, mine is now slightly wandering between 0.0 and 0.6, while it was showing 0.0 during a previous check, but that was with a belt that had been on for about 80K miles. My economy appears to be slightly better than before, but by nature I am a "messer" who likes to experiment with additive such as Millers, Fuel Set, 2 stroke oil, acetone and currently 2-EHN so while I always use Tesco diesel, dependant what "additive" I have the chemical composition of the fuel in the tank could always be different.

[faboka vrs]

Edit wrong thread.

[KeithCheetham]

Hi all,

I had a search and find a few similar threads but with different engines.

I have a 54 plate fabia 1.4 tdi 3 cylinder and just had the cambelt changed, with the water pump and tensioners etc. All using genuine parts where available.

My concern is the fuel economy, it's dropped quite a bit. I do 600 miles a week, pretty much all motorway and have averaged according to fuelly, 67mpg. Since the belt change that is dropping to barely 52 mpg. I used to be able to get 600 miles ish to a fill up, now its 480 ish.

I'm not familiar with the engine so i don't know if it can be adjusted like some of the 1.9tdi's or if it's ecu based.

The other thing different is it starts instantly instead of spinning over once or twice first, then runs like a bag of crap for a few seconds.

Sounds like the timing isn't right to me. Anyone got any ideas or details of how to sort the timing?

I want my mpg back

Any help greatly appreciated.

Baz

 Any updates/resolutions to the problem.