Performance Loss

[leegt5]

Yeah my car pulls hard when you hold the revs upto 3.5k off boost then nail it, but if I boot it from 1k I can hear the leaking sound and it doesn't pull hard and only boosts to 4psi !!

 

[T7ODD]

I finally got VAG-COM working on the car and 4 engine faults were found

16500 - Engine Coolant Temp. Sensor (G62): Implausible Signal
P0116 - 35-10 - - - Intermittent
17536 - Fuel Trim: Bank 1 (Mult): System too Lean
P1128 - 35-00 - -
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-10 - - - Intermittent

I'm guessing by these results that the engine coolant temp sensor is the infamous one which goes! But how can I tell if it's the one where you have to buy a whole new coolant bottle or the other one?

MAF is obviously causing the performance issues. The highest MAF reading I obtained seemed to be about 70 g/s when booting it. Would this be causing the fault of running too lean on bank 1 or is that something else?

No idea what the "terminal 30 - voltage too low" is as VAG-COM live reading were 14.0V for the battery.

How do I know how old these faults are? I had a problem with the water temp beeping at me when i first started back in the very cold winter mornings but the water temp gauge seems to be fine since then.

Thank you.

 

[-=Rob=-]

Have you disconnected the battery at all recently? Maybe to do a throttle body alignment? This will cause the voltage too low error and nothing to worry about if thats what you've done....

 

[T7ODD]

Have you disconnected the battery at all recently? Maybe to do a throttle body alignment? This will cause the voltage too low error and nothing to worry about if thats what you've done....

Yes, I've disconnected both terminals one before a few weeks ago and the negative terminal a couple of times to reset the ecu when the problems started recently.

 

[-=Rob=-]

Yes, I've disconnected both terminals one before a few weeks ago and the negative terminal a couple of times to reset the ecu when the problems started recently.

That'll be the voltage too low errors that are logged. Nothing to worry about... Sounds like a new MAF is needed though.. And a temp coolant sensor... After you fit the MAF I'd do another TB alignment to make sure everything is starting on level ground...

 

[David_smith_909]

That'll be the voltage too low errors that are logged. Nothing to worry about... Sounds like a new MAF is needed though.. And a temp coolant sensor... After you fit the MAF I'd do another TB alignment to make sure everything is starting on level ground...

how do you do a TB alignement? is it something within vagcom or a manual jobbie

 

[quattroman]

Yes, I've disconnected both terminals one before a few weeks ago and the negative terminal a couple of times to reset the ecu when the problems started recently.

Hi T7ODD,
seen you about Torbay quite often,sorry to hear of your woes,if all else fails give Matt Smith a ring at Volkscraft in Exeter -he is ex Seat and Master Technician of the year -3 years running and really knows his stuff -put it this way - Ive had a noise comming from final drive for a while- took car into dealer and they said they couldnt get a techie to test drive today-all too busy-So i said lets stop the playing games -Matt Smith drove the car and said Diff is far too noisy- needs a new gearbox-10 mins later new gearbox on order.-under warrenty of course.
So I think he might be able to sort you out if he has that kind of reputation.
Best of luck
quattroman

 

[acidstrato]

how do you do a TB alignement? is it something within vagcom or a manual jobbie

just disconnect the battery for 10mins or so and then reconnect it and leave the ignition lights on for another 5minutes without starting the engine...then under the bonnet u can hear the tb aligning...like a whining sound

 

[David_smith_909]

just disconnect the battery for 10mins or so and then reconnect it and leave the ignition lights on for another 5minutes without starting the engine...then under the bonnet u can hear the tb aligning...like a whining sound

aaaaah right, i see, cheers fella

 

[T7ODD]

Hi T7ODD,
if all else fails give Matt Smith a ring at Volkscraft in Exeter

Thanks for the contact info
I'm fitting a new MAF on Saturday and will do a throttle body adaption and clear the faults. Then I'll do some vag-com logs again.

 

[brad_cupra05]

i have recently had clutch pedal replaced could that effect it all ie the drive by sensor etc ?

 

[cupra tda]

I Had The Same Problem, Done A Tba And My Car Has Never Been As Fast. Where Abouts Is Matt Smith To In Exeter As I Am From Crediton And Need Some Work Doing.

 

[quattroman]

Hi there -Matt Smith can be contacted on 0777 202 5999.
or try this search for volkscraft on google.
He is mobile ie has a van and all the kit or you can arrange to visit him.
I saw him on Monday and he travelled down to Torbay to sort my neighbours A3 Quattro out that had an ABS light comming on intermitantly- Replaced brake light switch under pedal box and now cured.
great guy -loads of knowledge - and cheaper than main dealer-where he is very well known.

 

[T7ODD]

UPDATE:
I replaced the coolant temperature sensor on the pipe leading to the top of the radiator and the MAF but the car was still running in limp mode so I disconnected the negative battery terminal for a while and then it seemed to be running OK, after a few blasts things seemed to be returning to normal (finally). I couldn't get access to a laptop so I setup the PC in the driveway and cleared the ECU codes
Now I'm wondering whether i needed a MAF or not because maybe the coolant temp sensor could have been causing bank 1 to run lean, oh but then there's the 70g/s MAF reading, but then again the car was in limp mode Oh well, I spent £115 in total and it seems to have done the trick.
A few days later I had access to the laptop and the fault codes hadn't reappeared
I did a couple of 3rd gear runs (2000-6500rpm) measuring blocks 003, 020, 115 and 118 - not even sure if these were right. The requested and actual boost aren't too far off so I guess this rules out my original N75 theory. Could someone who knows what they're looking at take a look for me please???

Blocks 003 and 020 HERE
Blocks 115 and 118 HERE

 

[djscorch]

I hear the same sound coming from around the DV .
I replaced plastic Bosch with Forge , but leaking/vacum sound is still there !!!
And I also hear presure dump noise like I was having Blow-Off !!!
That's very strange

Hi, i'm having the same problem, what did you do to fix it?