2005 GTI "Flat Spot" and cutting out.

Started by Kiwi Carguy, July 01, 2016, 07:18:22 PM

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Kiwi Carguy

Hey guys.

First time posting after recently buying a 2005 Golf GTI. Its 2 owners, NZ new, 85,000 Kms, fully serviced etc with no modifications.

We've had the car for almost to months and love it however on the way home from a holiday it lost power going up hill. I was in the passing lane and doing around 100-110kph and it just lost power, no response from the peddle, revs slowly dropped but no lights on the dash. I pulled back into the left lane and a second or 2 later power was back as normal and for the rest of the 3 hour drive home.

Now it also has a flat spot that is particularly obvious coming into low speed corners at say 60kph decelerating down to 20-30kph and as you exit the corner back on the throttle. Its at this point with rev's around 1000rpm that its virtually "flat" there is what feels like a 1-2 second delay and then depending on how much you have depressed the throttle the car then takes off. 

Now I've owned several turbo cars both standard and high horsepower and it is not what I'd consider as just turbo lag. I'm also aware its FBW and although it could be this I can't believe the factory would allow it to be so bad? So I am not sure if I have two problems or one problem thats causing two symptoms?

I've checked the ECU with my own OBD2 reader and its showing no faults. I also replaced the DV valve with the latest version as I had read that displayed similar symptoms as loss of power however the flat spot is still there after the new DV valve was installed. I also checked the diaphram on the old valve and it actually looked ok. 

So any ideas guys? I greatly appreciate your help otherwise its off to VW service department $$$.

2005 Golf GTI
1996 Porsche 911
1993 Ducati 851

GLIDN

where abouts are you located in NZ?
Happy to assist and take a look for you if needed?

Sounds like low pressure fuel pump, cam follower for high pressure fuel pump or fuel filter/ high pressure pumps low pressure sensor.
None of these would fault an error code.

But logging and monitoring will show the weak links.
Audi A4 DTM - K04 NZ New | All bolt-ons | Carbon Clean done
2012 MK6R Golf |Stage 3+ | Stage 4 DSG | Tuned & Built by HSP Tuning

RS ZWEI

Quote from: GLIDN on July 04, 2016, 08:52:22 AM
where abouts are you located in NZ?
Happy to assist and take a look for you if needed?

Sounds like low pressure fuel pump, cam follower for high pressure fuel pump or fuel filter/ high pressure pumps low pressure sensor.
None of these would fault an error code.

But logging and monitoring will show the weak links.

He's in the lower North Island.
1980 VW Golf GTI Track Car
1995 Audi RS2
2003 Mini Cooper S (Written off - rear ended)
2005 Mini Cooper S
2006 Skoda Octavia vRS Combi
2009 Renault Megane 230 R26 (Written off - rear ended)
2013 Renault Megane RS265 Redbull RB8

GLIDN

Quote from: RS ZWEI on July 04, 2016, 09:36:20 AM
He's in the lower North Island.


Thanks Nik

Then at this stage I recommend getting someone local do some logging and go from there. If you really get stuck?
Send me some of the logs. Otherwise I will try and advise best I can with information presented.
Audi A4 DTM - K04 NZ New | All bolt-ons | Carbon Clean done
2012 MK6R Golf |Stage 3+ | Stage 4 DSG | Tuned & Built by HSP Tuning

Kiwi Carguy

Thanks for all the replies. Much appreciated.

I'm on the Kapiti Coast. I've had the Golf for a couple of months now and love it. Funnily enough it's actually my wife car but yeah its a fun little car to drive. The Diverter Valve was a cheap easy job that appeared to be a wear and tear item anyway so I was hoping to find it was buggered but it was actually fine... well at least I thought it was.

Interestingly my wife asked me to take it to work the other morning and when I left from home the fuel light was on. Little did I know it had been on for a while and I ran out. The reason why I mention this is from a driving perspective it displayed exactly the same characteristics that it did when it cut out (loss of power) on the way home from Rotorua so I did wonder if it could possibly be the fuel pump?

The car is NZ new, 2 owner with the 1st owner being an old lady and the 2nd was CEO of a big company so its been well looked after and fully serviced. I put it in for a full service and inspection straight after picking it up and everything checked out good, so all round its a tidy car.

I'm starting to wonder if the flat spot at low speed is actually a DSG thing and the box needs recalibrating as I tried it in manual and dropped from 3rd into 2nd and it didn't seem to have that same flat spot. Its like you enter a low speed corner in 3rd and exit in 3rd rather than it popping into 2nd...hence the lag? 
2005 Golf GTI
1996 Porsche 911
1993 Ducati 851


Kiwi Carguy

Thanks Schattenblau,

I probably should be clearer. I'm experiencing two issues.

1) At low speed decelerating into a low speed corner and then accelerating out. There is a one to two second delay which I am now thinking may be the DSG in the wrong gear?

2) the loss of engine power. This has happened on two occasions and under throttle passing another car on a passing lane... then simply no power... I had to pull back into the left lane until the the engine came back on line again. I replaced the DV hoping this would cure it but wondering now if its the fuel pump or fuel related.

The thing is if it was my car I could get use to the DSG "driving aspect" and getting the most out of the DSG but its my wife's daily driver and she's wheelspining it up out of corners taking the kids to school lol. She just want to get in and drive it... not have to "think" about the DSG.
2005 Golf GTI
1996 Porsche 911
1993 Ducati 851

GLIDN

I'm going to go out on a limb and say you need scan with VCDS or a scanner that can read via CANBUS. As most generic scanners do not support CANBUS.
Had a similar experience where by the car felt like and almost cut out while driving down the motorway early last year.

After extensive logging, checking defaults and a few other things, It appeared that the in tank fuel pump was the cause or possible issue.
Also a 2005 MK5 GTI. Replaced with following all the recommended procedures afterwards. The car is running better than it ever has before.
No error codes were present until the car stalled around 2 months ago and would not start. Which is why logging what was going on route/approach was taken.
Audi A4 DTM - K04 NZ New | All bolt-ons | Carbon Clean done
2012 MK6R Golf |Stage 3+ | Stage 4 DSG | Tuned & Built by HSP Tuning

Kiwi Carguy

Thanks GLIDN. I'll follow up on the items you've mentioned and see how I go and report back.
2005 Golf GTI
1996 Porsche 911
1993 Ducati 851

insane

Interested in how you got on with the delay in acceleration after it changes down from 3rd to 2nd before accelerating again? I notice the same on one particular corner I regularly take and always wondered what may be the cause. Nothing shows up on the VAGCOM so perhaps I need to log it too.


GLIDN

Just following up to see how you got on?

I recently helped another forum member. Did some logging at noted N75 was working at maximum capabilities.
Managed to identify the problem area quickish. recommended repair to be done.

I had no parts available on a saturday arvo to be able to swap out. 
Audi A4 DTM - K04 NZ New | All bolt-ons | Carbon Clean done
2012 MK6R Golf |Stage 3+ | Stage 4 DSG | Tuned & Built by HSP Tuning

Kiwi Carguy

Just thought I'd update this thread. I never got to the bottom of the flat spot/cutting out. 99% of the time the car was brilliant to drive.... the issue mentioned was the only negative. A couple of weeks ago I put the car in for a big service, cam belt etc and after getting it back it started missing under any more the 25% acceleration and the symptoms above appeared much worse. This was great as finally it could be diagnosed and fixed but more importantly as I purchased a mechanically warranty with the car it meant it got all done under warranty.

The diagnose was the high pressure fuel pump up front, not the one in the tank. It goes in on Monday so hopefully a totally different beast come Monday arvo :)

Thanks to all those who commented.
2005 Golf GTI
1996 Porsche 911
1993 Ducati 851

The Red Warrior

Do you know what was actually wrong with the HPFP? Something inside the pump, a sensor or the good old cam follower wearing through? My money is on the latter. Good thing you got the mechanical warranty.
Let us all know, I hate it when threads just fizzle out with no mention of what the problem/solution was.

Kiwi Carguy

I'll know more when I get it back on Monday. The mechanic did mention the cam issue so I'll get the full rundown and post back here. Like you I hate it when a thread is not resolved. Just hope it helps someone else in the future. That being said now that I know the issue and have Googled the fault code its a known fault on the top 10 list for GTI's  :(
2005 Golf GTI
1996 Porsche 911
1993 Ducati 851

DTM

A friend of mine had a similar issue and basically changed everything from turbo,in tank pump, n75 valve ,checked dv,new pcv valve,new cam follower the list goes on. And spent a hell of allot of money with the issue unresolved.

He then decided to go over his car again and found the small rubber cap On the intake manifold on the end had perished so it was bust , basically bought a new rubber cap for around $2.00 and problem solved. I'm not saying this is your issue but definetly worth a check.

22


Kiwi Carguy

I use Steve Gross who was ex head mechanic at Porsche in Wellington. He also looks after my 911. He's done all the work on it to date and diagnosed the fault. However the warranty company only uses "approved garages" and where Steve is now isn't approved so under his recommendation I took it to AVS in Paraparaumu. So far AVS have been great to deal with. Certainly knowledgeably and thorough.

Only criticism of AVS is no courtesy car :( Don't know why garages don't see the value in a cheap courtesy car. If they did it right they could keep turning over the courtesy cars and make a small profit on the resale. By a non runner, repair, loan out, then sell.
2005 Golf GTI
1996 Porsche 911
1993 Ducati 851

GLIDN

Quote from: Kiwi Carguy on April 02, 2017, 03:32:58 PM
I use Steve Gross who was ex head mechanic at Porsche in Wellington. He also looks after my 911. He's done all the work on it to date and diagnosed the fault. However the warranty company only uses "approved garages" and where Steve is now isn't approved so under his recommendation I took it to AVS in Paraparaumu. So far AVS have been great to deal with. Certainly knowledgeably and thorough.

Only criticism of AVS is no courtesy car :( Don't know why garages don't see the value in a cheap courtesy car. If they did it right they could keep turning over the courtesy cars and make a small profit on the resale. By a non runner, repair, loan out, then sell.

I have seen the top sensor on the HPFP fail. Usually due to slack mechanics and simply whack the head of that plug while installing OEM intake.
If that sensor has a fracture or crack? The HPFP is good for the bin, no replacement for that sensor available.

Other thing was when diagnosing a 400HP golf R build 4 weeks ago, also had the cut out, again logging everything.
Actually found the low pressure sensor on the high pressure fuel pump was faulty. Anything more than stock request would cause the low pressure fuel pump controller to over heat and shut down the car.

Audi A4 DTM - K04 NZ New | All bolt-ons | Carbon Clean done
2012 MK6R Golf |Stage 3+ | Stage 4 DSG | Tuned & Built by HSP Tuning

Kiwi Carguy

Well got the car back after having the high pressure fuel pump and shim replaced but unfortunately the miss and flat spot is still there. Dropped it back to AVS and upon closer examination the camshaft needs replacing. Soooo stoked right about now that I coffed up for the 3 year warranty. New cam/parts etc on there way and will hopefully have it all sorted once and for all. Warranty company has been great to deal with as well as Chris at AVS.

I hummed and harred over paying for the warranty but figured any issue with the DSG would well and truely pay it back. Never did I realise it would be doing this! Weird thing is the car was 2 owners NZ new, fully serviced at Giltraps and the owner was CEO of Chevron and used the car to drive from his house to the office. So as it was well looked after and not thrashed I expected it to be fairly trouble free.
2005 Golf GTI
1996 Porsche 911
1993 Ducati 851

Candywhite

This is interesting as it is linked with the Rev. A cam issue with earlier GTI's (vs the 2 piece updated Rev.B cam). I am concerned about the same issue with my GTI (Rev.A) cam, however talking to a couple VW mechanics from Giltraps and Continental, most have said that they have never seen an issue with a Rev.A/cam follower failing. However, clearly it is a risk to be aware of!