still got starting troubles (sorry for the essay)

[Chris 'N' Jen]

Hey y'all

Instead of resurrecting an old thread ill post a new with a link to the old so you can see the history.

http://www.golfgtiforum.co.uk/index.php?topic=73781.0

Right;

It went into lookers vw at Darlington for a diag. The mech said the ECU held no faults even though there had been lights on the dash. He said that after 12 or so restarts the ecu erases error codes if they haven’t re-occurred. Is this the case? The mech said we'd have to take it in sometime and leave it with them overnight as it was a cold starting issue because the ECU gives a different reading when its cold. I though BS strait away. So we took it back in on fri to get looked at yesterday morning.

Now for the interesting bit.

Gets a phone call at 11 to say there was nothing wrong with it and they claim it started perfectly. Now we know this is absolute bull sh!t as we've had cold starting issues for months now. I have a feeling mr intelligent vw mech plugged his very expensive computer into it and it said there was no errors so nothing more was done. Fair enough. All we asked for was a diag and a bit of advice on what it could be.

Now for the infuriating bit,

As I wasn’t available to pick the car up, Jen had to go through for it, this wasn’t until 12.00. When she drove off they had managed to clock up at least 12 miles in it. For a cold start issue I find a test drive highly unnecessary as this would put it in the same position as when we took it in the first time, not to mention a 12 mile test, what the f**k was he testing. The total MPG counter had also gone down from 32 to 31.8. Coincidence maybe. The only way this should have happened is if the car was running for a long time (remember this is a cold starting problem we're having here) or being thrashed as I cant get it to go that low. 
Also, when we dropped it off we always turn the stereo off. When we got it back the stereo was on half volume. I find it hard to believe that the cd we had in played at half volume held the key to our starting problems. We have nearly a grands worth of ice in there I don’t really want some greasy handed f**kwit messing with it. (My fault maybe for not taking the master fuse out before we took it in)

Out of this I have 2 questions for everyone.

1. Do I have any comeback on these tit heads for thrashing our car?
2. What the hells wrong with it?

The plugs have been changed, as have all the filters, the temp sender and supposedly had the throttle body cleaned too.

Cheers all

 

[rheady]

I doubt they've even cleaned the throttle body! Might be interesting to ask why they clocked up the mileage when as you said its a start up issue. Why is it you can't even trust the so called pro's. Also VW wanted to charge me £150 to change my throttle body for possibly 20mins work.

[Saffa]

Hi,
I would check the throttle body is clean, this is very common on the 2.0's, my wife has one, which had problems starting, and also stalled easily.
Once cleaned out, it took about a week for the idle speed to sort it's self out as it kept idling at 1200.
But now starts and runs and idles perfectly.
The only other common 2.0 problems are the lambda probe and air mass meter, both of these can be checked on the vw diagnostic computer even if there is no stored fault.
Hope you get to the bottom of the problem.
As for the 12 mile roadtest? totally un acceptable if it was only booked in for a cold start check!!
Regards,
Jochen.

[Chris 'N' Jen]

cheers for the advice mate.

Where is the lambda sensor located? When you say the air mass meter, is that the one near the air box or am i getting mixed up with the MAF?
Supposedly its had the throttle body cleaned once before which cured the problem for about a month or so. Would it be adviseable to replace it? is it an expensive part?

Thanks again

 

[ub7rm]

the air mass meter and the MAF are one and the same.  Generally if you have MAF / o2 (lambda) sensor probs it will result in your car running rich which will soot up your throttle body - so if cleaning it cured it for a month it suggests that it could be your problem but somethings else is wrong which is causing it to soot up quickly.

My mate has a 2.0 which had rough running / poor mpg issues.  Nothing came up on VAG-COM except occasional missfires but after a lot of trial and error the o2 sensor was replaced and cured it.  Sometimes its not broken enough to generate a fault code but broken enough to cause a problem!

On a final note, make sure your oil is at the right level.  The 2.0's drink it like a fish and having a low oil level seems to cause them to run rough / poor mpg as does overfilling them.  (Which would probably kill the O2 sensor...).  That said I wouldn't have thought that would cause any cold start up issues.

Lambda sensor is screwed into the exhaust system - I'm afraid I don't know exactly whereabouts it is on the 2.0 but it will be either in the manifold or just after the downpipe (usually.....)

HTH

[Chris 'N' Jen]

the air mass meter and the MAF are one and the same.  Generally if you have MAF / o2 (lambda) sensor probs it will result in your car running rich which will soot up your throttle body - so if cleaning it cured it for a month it suggests that it could be your problem but somethings else is wrong which is causing it to soot up quickly.

My mate has a 2.0 which had rough running / poor mpg issues.  Nothing came up on VAG-COM except occasional missfires but after a lot of trial and error the o2 sensor was replaced and cured it.  Sometimes its not broken enough to generate a fault code but broken enough to cause a problem!

On a final note, make sure your oil is at the right level.  The 2.0's drink it like a fish and having a low oil level seems to cause them to run rough / poor mpg as does overfilling them.  (Which would probably kill the O2 sensor...).  That said I wouldn't have thought that would cause any cold start up issues.

Lambda sensor is screwed into the exhaust system - I'm afraid I don't know exactly whereabouts it is on the 2.0 but it will be either in the manifold or just after the downpipe (usually.....)

HTH

The running rich part of your reply sounds very true. If i start it and it stalls, when it does eventually start again the fumes smell rich. I wonder if i should change them 2 sensors. I think it would be a start. Is the sensor in the exhaust an easy fix as it goes to get lowered on sun so ill get them to do it while its on the ramps.

Iv heard about it loving oil so i do check it weekly but cheers for the tip.

Would some fuel system cleaner get the sh!te of the throttle body or do i have to take it apart?

Thanks for the info mate. ill try the sensors.

Ill update the thread when i change em. Meanwhile if anyone has any other ideas please feel free to post them. i would be most greatfull.

 

[rheady]

I was quoted £150 for the throttle body from VW, this was a drive by wire model.

[Chris 'N' Jen]

I was quoted £150 for the throttle body from VW, this was a drive by wire model.

Cheers for that mate. gives me something to work with.

[ub7rm]

The running rich part of your reply sounds very true. If i start it and it stalls, when it does eventually start again the fumes smell rich. I wonder if i should change them 2 sensors. I think it would be a start. Is the sensor in the exhaust an easy fix as it goes to get lowered on sun so ill get them to do it while its on the ramps.

The sensor just screws into the exhaust so if you've got her up on the ramps this would be a good time to do it.  The part ain't exactly cheap - genuine VW part cost me about £100 - but you might be able to get a cheaper one.  On some cars its possible to change the O2 sensor in the engine bay as it screws into the manifold but as I say I'm really not familiar with this engine.

I wouldn't imagine you need to replace your TB, fuel system cleaner never hurts but it won't clean out your TB.  Its a fairly simple process to clean it yourself.  There is a guide how to do it for the 1.8T in the mk4 section (recent) which should give you a good idea what to expect.  Although I think the 2.0's TB have a coolant line into them which adds a further complication.

[Chris 'N' Jen]

Cheers for that mate. Ill get some fuel system cleaner through it.

Also, which of the sensors do you think i should go for first. The MAF near the airbox of this one in the exhaust or just do em both.

Iv seen the throttle body clean but things like that scare me somewhat, not that i doubt my ability to do it, just if anything goes wrong sumit gets f'd up.