Engine light on - but running perfect.

Chat about your MKV (6N2) Polo
Post Reply
RayD
Getting There!
Posts: 79
Joined: Sun Apr 12, 2009 1:06 pm

Engine light on - but running perfect.

Post by RayD »

Had the engine light come on Dec 2009, found No1 plug misfiring – changed the plugs - light went out - all OK.

Last week, engine light came on No1 plug misfiring - changed the plug – still missing, although not as bad - changed the leads – totally transformed the car – it performs better than it ever did.

It now seems the leads were on their way out in December and were the cause of the plug deteriorating.

But ... the engine light is still coming on – disconnected the battery to take it off but it returns shortly afterwards. The engine is still running perfectly.

Do you have a list of codes?
How many things can cause the light to come on?
It seems to be related to this plug escapade so could it be the wrong gap?
What is the correct gap for the 2001 1.0l E?
Any other ideas welcome.

Ray
emma_88
Gold Member
Posts: 798
Joined: Tue Mar 03, 2009 10:49 am
Drives: 6N2 Polo GTi & 9N3 Polo GTi
Location: Maryport, Cumbria (North West)

Re: Engine light on - but running perfect.

Post by emma_88 »

The engine management light can come on for many reasons.

You should get it plugged into VAG-COM then post up the fault codes, and I'll be able to help :)
User avatar
red6n2
Bling Bling Diamond Member
Posts: 2090
Joined: Wed Mar 25, 2009 8:51 pm
Location: Northampton

Re: Engine light on - but running perfect.

Post by red6n2 »

my engine light used to be on and around dec-jan it just switched itself off hasnt come on since !... happy days
User avatar
alexperkins
Site Admin
Posts: 14866
Joined: Sat Nov 11, 2006 5:29 pm
Drives: 91 Golf GTI, 01 TT 225, 54 T5 174
Location: Poole, Dorset, UK.
Contact:

Re: Engine light on - but running perfect.

Post by alexperkins »

Agreed with emma - get the vagcom error code as it can be 101 different things that make it come on!
RayD
Getting There!
Posts: 79
Joined: Sun Apr 12, 2009 1:06 pm

Re: Engine light on - but running perfect.

Post by RayD »

... it had to be related to the plug episode or we’d gathered a new problem on the same day the leads were changed.

On closer inspection one of the vacuum pipes had come detached as I’d lifted the cover – replaced – disconnected the battery to get the light off – went for a run – all OK

Thanks again for the replies.

Ray
RayD
Getting There!
Posts: 79
Joined: Sun Apr 12, 2009 1:06 pm

Re: Engine light on - but running perfect.

Post by RayD »

Second trip out and the light's back on so it wasn't the vacuum pipe.

Is there a cheaper alternative to VW's 1 hour labour charge for identifying the code/s.

Ray
User avatar
lowfoon
Gold Member
Posts: 617
Joined: Thu Dec 18, 2008 10:20 pm
Location: Croydon, Surrey
Contact:

Re: Engine light on - but running perfect.

Post by lowfoon »

Buy a cable from ebay :D
RayD
Getting There!
Posts: 79
Joined: Sun Apr 12, 2009 1:06 pm

Re: Engine light on - but running perfect.

Post by RayD »

According to the VW computer this morning ... it's the EGR valve ... any tips would be welcome.

How do they fail?
Are they repairable?
Best place to buy and how much?

Thanks Ray
User avatar
alexperkins
Site Admin
Posts: 14866
Joined: Sat Nov 11, 2006 5:29 pm
Drives: 91 Golf GTI, 01 TT 225, 54 T5 174
Location: Poole, Dorset, UK.
Contact:

Re: Engine light on - but running perfect.

Post by alexperkins »

Did they provide you with the fault code ray? Itll help greatly if they did!
RayD
Getting There!
Posts: 79
Joined: Sun Apr 12, 2009 1:06 pm

Re: Engine light on - but running perfect.

Post by RayD »

No Alex,

I only called at the VW dealership to thank one of the technicians who’d correctly advised me over the phone to change the leads earlier in the week.

When I told him it was now running perfectly but with the light coming back on he offered to connect the computer.

After doing so he announced quite specifically it was the EGR.

Not realising there might be more than one code associated with the valve and having had it done free of charge I left it at that.

Are you saying the particular code would have told you what was wrong with the EGR ... and whether it could be repaired rather than renewed?

Edit: is there a fault that could have been caused by the pipe to the top box being disconnected for a while?

Ray
User avatar
alexperkins
Site Admin
Posts: 14866
Joined: Sat Nov 11, 2006 5:29 pm
Drives: 91 Golf GTI, 01 TT 225, 54 T5 174
Location: Poole, Dorset, UK.
Contact:

Re: Engine light on - but running perfect.

Post by alexperkins »

Ah fair play - might be worth giving them another call as all scans are generally logged.

Yes - there is generally a specific code which relates to a specific fault, as faulty parts can have many faults like a short circuit, a mis reading, a non working part of the main part.

Its unlikely that would have caused it. The EGR is vacuum powered, but theres an electronic side to it too.

What engine code is yours?
RayD
Getting There!
Posts: 79
Joined: Sun Apr 12, 2009 1:06 pm

Re: Engine light on - but running perfect.

Post by RayD »

Thanks Alex,

The engine code is AUC

Ray
RayD
Getting There!
Posts: 79
Joined: Sun Apr 12, 2009 1:06 pm

Re: Engine light on - but running perfect.

Post by RayD »

RayD wrote:According to the VW computer this morning ... it's the EGR valve ... any tips would be welcome.

How do they fail?
Are they repairable?
Best place to buy and how much?
Can it be opened up and examined? - is there a chance it could just require freeing off?

Thanks Ray
inder
Platinum Member
Posts: 1842
Joined: Sun Feb 27, 2005 8:37 pm

Re: Engine light on - but running perfect.

Post by inder »

is it possible to 'clean' these EGR valves, say with carb cleaner?

would it be wise to replace with a used one or go for new?

apologies for jumping on this thread, but seems topical

cheers,
Post Reply