Beetle idle speed

[oldGTI nut]

Hi All,

We have a 2004 reg beetle cab with a 1.6 BFS engine. On tickover often when cold or hot it surges/hunts from normal tickover speed to about 1500 rpm then back to normal very quickly. This lasts for about 15 seconds, then returns to normal and stays there.

Also it wont rev cleanly until about 2000 rpm at any time, hot or cold .

Its been on the VAGCOM with no codes. The specialist that fixes it is reluctant to change parts at random. I am sick of it so what part do I change first? Temp sensor is my thought, cos this gave me stress on an Audi I had.

Once it was on vag com it came up with P0441 evap system, incorrect flow, but the surge was there log before showing this code.

Please help!
Ta
Simon aka oldGTInut

[Crasher]

The cold start behaviour is normal, it is the secondary air system running which is part of the strategy to speed up the catalyst light off time for reduced emissions. The poor throttle response is less clear with it not registering any fault codes so I would start by fitting a genuine VW exchange Air Mass Meter bought from a VW dealer, nowhere else under any circumstances.

[oldGTI nut]

Thanks for that Crasher, I will go to my local steal ers in Doncaster tomorrow for one. I did hope my query would be answered by you, cos you are the man! I have followed your columns in Golf plus with interest many times!!

Thanks again.

Will let you know if it works.

Simon

[Crasher]

I don’t do The Golf+ any more, they pooed on me from a great height when it all changed so I told them to take a run and jump.

One thing, calling dealers thieves is a banned word for good reason, it rather upsets me.

[oldGTI nut]

I did wonder where you had gone to from the mag, I dont buy it now. Sorry if you thought I included you in my words about the dealers, I do know you are a well respected Specialist and as such did not include you in this. Many apologies.

I do have a good relationship with the main dealers parts staff, they are helpful and still can get most stuff I need for my mark 2 Golf GTI, surprisingly.

Thanks alot.

Simon

[Crasher]

No I didn’t think you included me, I just don’t like dealers being called thieves. A lot of them are incompetent, rude and generally useless but the ******** term has started to get out of hand on the internet.

[blakey77]

My wife has a 2003 Beetle Cab with the BFS engine, it doesn't have an erratic idle generally (sometimes when cold) but it has always been lumpy/hesitant at lower rpm's.
Last year the post cat oxygen sensor failed, which I thought it's deterioration may a contributing factor but there was improvement following it's replacement. I also changed the MAF around the same time, with no real change following. I recently changed the coolant temperature sensor, again no change.

All of the above parts were genuine and apart from the oxygen sensor failure, the engine has always been fault free when checked with VCDS.

It is fairly good on fuel and drives well otherwise, with out carrying out lots of data logging, I've come to the conclusion that it's 'normal'.

It would be interesting to see how you get on Simon, and if anyone else has any similar experiences.

[oldGTI nut]

Hey Blakey.

The new AMM will be here Tuesday so will let you and Crasher know the results. I do realise it'll be a process of elimination for this fault. Its a pity the parts list possibly required will cost quite a bit.

I've had six mark 2 Golf GTI's over the last 16 years and still have one now. Never had this stress from the electronics with those ( cos there isnt many!)

The joke is on me tho; I traded in a beautiful Audi A4 3.0 sport quattro 2003 that my main dealer had 6 times for a fault they couldnot fully fix. Got fed up traded it for the Beetle and this is going the same way.

Bought another mark 2 Golf GTI, Great car!

Simon

[oldGTI nut]

Hi Gents,

The A.M.M arrived today and was fitted by me and there is no change to its antics. The AMM was from VW, £95 odd. I guess I am going to bite the bullet and take it somewhere with a blank cheque.

Last winter it conked out, that was an engine impulse sender. I hoped that (nievely) would have been this tickover fault rearing its head and developing but it wasnt.

Checking the mileage tho, the wife has only done 800 miles since 18.12.2008, when the imp. sender was fitted.

Annoyingly for me, I am a Time served Motor Vehicle technician by trade , but have been out of it for some years and computers / multiplex etc came along and my diagnostic skills are now obsolete!!!

Any ideas lads?
Thanks
Simon

[oldGTI nut]

I couldn'nt allow myself to send it some where with a blank cheque so if any one has anymore ideas I would appreciate it!

Thanks
Simon

PS Golf Rallye Show on sunday 2nd Aug at Elsecar, Barnsley, South Yorkshire! Open to all Supercharged VWs .

[Crasher]

Another code read now.

[Gasflowedhead]

My girlfriend has the same car and engine and the same problem. Just serviced it and plugged the electric doo-dah in to find out the code and why the engine management light was on. This came up with four possibilities. One was what you have already tried; another being the EGR valve and at moment cant remember what the other two were. My dad (a mechanic) says these valves carbon-up and you can take them off and clean them, which will be my first port of call. Was coming on here to find out how to take one out :D as the engine is a bitch to work on and the valve is way at the back on the right hand side! Try this an let me know the outcome...Cheers another Simon with a poo-pants Beetle (but chicks love em).

[orienteer]

To help we need car's mileage and the codes off a VAG-COM reader.

An ideal regarding the performance would be to make a comparison against a Bug that has the same engine.

The VAG-COM software also helps to check e.g. engine temperature, mass air flow reading, pre cat lambda readings a much more. These all help to build a picture of what's happening.

Regards, Ian

[oldGTI nut]

Thanks to Simon and Ian for the above.

Looked at the EGR valve looks a bitch to remove and does not look as if its cleanable/strippable.

There has not been fault codes before when this fault was happening. We did once get a P0441 code the evap emission system but the specialist did not know what it could be.

Consensus with many people was the AMM but it was no different with a new one.

I think Ian a comparison is a good idea but I am sure this is not normal behavior.

Thanks from a long time VW owner (a Mark 1 Scirroco in 1984 started this obsession) but now disgruntled with this poor quality car.

We own a super B5 Passat family car that is excellent, a lovely Mark 2 Golf GTI that is mint and this Beetle Cab that looks great!

Simon.