lumpy running V5 Bora - Please help

[jih198]

Hi All,

I was wondering if any of you may be able to offer some insights into the lumpy running of my V5. It has been in and out of the garage 5 times now, and the fault is still not cured. All the obvious things have been checked and changed: Spark plug leads, spark plugs, ignition coils etc. but still no joy. The engine is sounding like a tractor, and there is no power at all. Also, the fuel consumption has soared...

Any insights would be most welcome!

Thanks,

J

[VW-A-Specialist]

Air flow sensor?

A good way of finding this out, is to unplug it your self then drive it to bottom of your street and back, if no change then its probably not this. if it runs like it should do then this is your problem, however your Engine Management light might/will come on.

Thanks

[jih198]

Air flow sensor?

A good way of finding this out, is to unplug it your self then drive it to bottom of your street and back, if no change then its probably not this. if it runs like it should do then this is your problem, however your Engine Management light might/will come on.

Thanks


Thanks for the advice, I will give it a go. It seemed to start running like this shortly after a service. Is this something that could have been knocked during a routine 80,000 mile service?

Thanks again,

J

[VW-A-Specialist]

Was this a cambelt service?

[jih198]

Was this a cambelt service?

No, otherwise I would have suspected the cambelt, but apparently the v5 has a chain.

Tried the air flow meter and no joy. Its going back into the garage today. Will let you know what the findings are.

Cheers,

J

[VW-A-Specialist]

They do have chains, sorry.

Hope you get it sorted.

[jih198]

They do have chains, sorry.

Hope you get it sorted.

Thanks,

I will let you know what the problem is if it is eventually found,

J

[VW-A-Specialist]

To tell you the truth, my dad will know, I just know the odd things about mechanically finding faults, as my dad is a very highly skilled mechanic and specialises in VAG cars, hes really clued up about it, I'll ask him next time I see him and ask you. Its unlikely he wont know.

Thanks

[Col]

Coolant temperature sensor.

[jih198]

Coolant temperature sensor.

Hi, I just had the temperature sensor replaced, as it was only working intermeittantly on the dashboard temperature guage.

Do you think this could be the root cause for all of the lumpy running and lack of power?

Thanks,

J

[VW-A-Specialist]

Now this could be true.

My mate has a Polo GTI, runs abit sluggish sometimes, erased all faults from ECU (Engine) and the Engine Coolant Temperature came straight back on. Fit one, and try it.

Edit: Sorry just read your post properly, only scanned it last time.. Has having this replaced solved your problem?

[jih198]

Unfortunately having this replaced didn't solve the problem.

The (current) theory goes that it is a a problem with the final stage unit, which is causing both the injectors and the new coilpack to play up.

Will let you know the result of changing this later today, as the part should be in soon.

Cheers,

J

[jih198]

Unfortunately having this replaced didn't solve the problem.

The (current) theory goes that it is a a problem with the final stage unit, which is causing both the injectors and the new coilpack to play up.

Will let you know the result of changing this later today, as the part should be in soon.

Cheers,

J

Turns out changing the end stage unit seems to have solved the problem.

still a bit up and down at idle, but all the power is back, and the engine is smooth on the move.

J

[darkskies]

Hiya,

On my Bora V5 the engine always ran a little roughly on idle, and I loved the way the garage de-tuned it on the services, making sure that it ran rougher and did worse mileage than before the service!

That said, I do love the V5. I did 80K largely trouble free miles in mine from new. Glad you sorted the problem.

Rob

[Seat til I die]

yeh V5 is a crackin engine, very torquey yet incredibly smooth.

i had this similar problem, was the only time ANYTHING ever went wrong with my toledo in 2 yrs and the problem was the oxygen sensor (air flow meter same thing, dont know???)

if its trouble free motoring youre after and you dont mind losing some mpg then the V5 just cannot be beaten there was no way i was letting it go for a diesel even the modern tdis cant compete with the V5 for drive, not even close imo.

[VW-A-Specialist]

Hi.

Bit late I know.. But you say its still up and down on idle? In lot of cases replacing the correct part will not 100% solve the problem, unless drove for a while. Most/All modern day cars have a self learning ecu, and its learnt there was a fault with your car,and ajdusted things to suit the problem or make it at least a bit better, and if you've replaced this, the ecu is still set up to run the engine asif the part was still faulty, best way to do this is have a VW machine put on it, and learnt values erased and fault codes. But it will eventually clear its self up after not too long of driving.

Glad you found out what was wrong. Heh at least you have a variety of new parts on your car haha.