Hi all
my jerkiness when accelerating hard in 3rd or 4th or driving uphill has deteriorated suddenly to the stage where it broke down completely on a dual carriage way with no hard shoulder and my 4yr old in the back seat.
some other symptoms that I had just prior to the breakdown included
I limped to a VW/Audia specialist nearby by stopping, switching off/on driving, stopping, on/off etc.
They were very helpful, put it on a ramp, took the under tray off and within 20 mins concluded there was a problem with the N75. They said tandem was OK, diaphragm on EGR (I think) was ok. they said it would be £540 to replace but the part was on back order and could take months or never for it to turn up from Audi.
I limped home and ordered a 2nd hand one from ebay, it's ( 6Q0906625F ) for the BHC engine and sits against the left hand side wing, it has 4 or 5 pipes leaving from it and a cable.
since I had a cheap Bluetooth odb2 thing connected from the day before the breakdown to read and cancel the P0299 I monitored some stats driving home from the garage. I recorded some stats including accelrator/speed and MAP (manifold pressure). The slower I got, the more accelerator I used but the MAP kept dropping despite demand for more air/fuel until it died. Sometimes it might recover to normal for a minute or two before it happens again.
I have been buying some lights from A2Steve and tried to buy a N75 from him but he didnt have one but he has been very helpful and suggested it is more likely to be a split/loose hose than N75.
One graph shows the accelerator at 100% but the MAP and MAF steadily declining, the other shows me increasing accelerator to try and fight the dropping MAP.
my jerkiness when accelerating hard in 3rd or 4th or driving uphill has deteriorated suddenly to the stage where it broke down completely on a dual carriage way with no hard shoulder and my 4yr old in the back seat.
some other symptoms that I had just prior to the breakdown included
- a p0299 (under boost warning)
- when I took my foot off the accelerator the engine would still run on for a second or so before power was reduced.
- after breaking down it would be very difficult to restart, sometime cranking for 30 seconds before it would fire.
I limped to a VW/Audia specialist nearby by stopping, switching off/on driving, stopping, on/off etc.
They were very helpful, put it on a ramp, took the under tray off and within 20 mins concluded there was a problem with the N75. They said tandem was OK, diaphragm on EGR (I think) was ok. they said it would be £540 to replace but the part was on back order and could take months or never for it to turn up from Audi.
I limped home and ordered a 2nd hand one from ebay, it's ( 6Q0906625F ) for the BHC engine and sits against the left hand side wing, it has 4 or 5 pipes leaving from it and a cable.
since I had a cheap Bluetooth odb2 thing connected from the day before the breakdown to read and cancel the P0299 I monitored some stats driving home from the garage. I recorded some stats including accelrator/speed and MAP (manifold pressure). The slower I got, the more accelerator I used but the MAP kept dropping despite demand for more air/fuel until it died. Sometimes it might recover to normal for a minute or two before it happens again.
I have been buying some lights from A2Steve and tried to buy a N75 from him but he didnt have one but he has been very helpful and suggested it is more likely to be a split/loose hose than N75.
- Therefore I want to buy some replacement hose to fit while I change the N75, does anyone know the ID and OD of a suitable vacuum hose?
- What are people's thoughts about the graphs below, does that tie in with a faulty N75 or a hose leaking or something else like a wastegate, EGR or anti shudder etc?
One graph shows the accelerator at 100% but the MAP and MAF steadily declining, the other shows me increasing accelerator to try and fight the dropping MAP.
