After a pierced oil pan an a blown stock turbo I've completed the job of getting my car road-worthy. It's an '04 Golf TDI PD 1.9 (BEW) with 5 speed tiptronic (09A).
While road testing the car and during a shakedown trip of ~115 miles I'm getting a new issue:
Seemingly randomly the car will act like it shut off for about ½ a second, engine power dies off smoke from the back, not thick, and a clicking/rattling sound like a ball rattling in a can three or four times type noise. After the ½ second power resumes and we drive on. This is not major electrical: AC fan, lights and gauges are not affected.
I don't notice the tach even react to the event it is so fast.
The turbo was upgrade to a VNT-17/22
There is no tune on the ECU yet.
No CEL and a "read" on my OBDII scanner shows no faults.
This has only happened at freeway speeds of 70+, at 75 with cruise control active seems to be the most frequent incident rate usually on flats or cresting a hill.
Each episode is slightly different, I don't always hear the rattle and it does also happen under foot throttle control but I've not had it happen under 60MPH.
Over the entire trip I think there were 6 to 8 incidents of this.
From the location of the noise (far as I can tell while driving) and its function I'm thinking the rattle type noise is the ASV tossing itself closed and open rapidly.
Does this seem like an issue where the turbo is putting out more boost in either spike or creep than the stock map is expecting for the load so the car tries to end the over-pressure by closing down air intake?
The black (looks to me from inside) smoke would indicate to me a low-air situation. There are only two air controls I know of: ASV and turbo speed via VNT. The turbo wouldn't spool down this fast and still work so I think this is the ASV.
Does all this sound like creep/runaway scenario? If so will the tune of the ECU that is in the works(mail) resolve this with the proper MAP and map installed?
If not, does anyone have any other ideas? My first thought was to disconnect the ASV and see if I can reproduce the issue. My fear is that if I'm right and the hiccup doesn't happen that I may damage something. Theoretically closing the throttle should end the event since ECU would terminate fuel injection, right?
While road testing the car and during a shakedown trip of ~115 miles I'm getting a new issue:
Seemingly randomly the car will act like it shut off for about ½ a second, engine power dies off smoke from the back, not thick, and a clicking/rattling sound like a ball rattling in a can three or four times type noise. After the ½ second power resumes and we drive on. This is not major electrical: AC fan, lights and gauges are not affected.
I don't notice the tach even react to the event it is so fast.
The turbo was upgrade to a VNT-17/22
There is no tune on the ECU yet.
No CEL and a "read" on my OBDII scanner shows no faults.
This has only happened at freeway speeds of 70+, at 75 with cruise control active seems to be the most frequent incident rate usually on flats or cresting a hill.
Each episode is slightly different, I don't always hear the rattle and it does also happen under foot throttle control but I've not had it happen under 60MPH.
Over the entire trip I think there were 6 to 8 incidents of this.
From the location of the noise (far as I can tell while driving) and its function I'm thinking the rattle type noise is the ASV tossing itself closed and open rapidly.
Does this seem like an issue where the turbo is putting out more boost in either spike or creep than the stock map is expecting for the load so the car tries to end the over-pressure by closing down air intake?
The black (looks to me from inside) smoke would indicate to me a low-air situation. There are only two air controls I know of: ASV and turbo speed via VNT. The turbo wouldn't spool down this fast and still work so I think this is the ASV.
Does all this sound like creep/runaway scenario? If so will the tune of the ECU that is in the works(mail) resolve this with the proper MAP and map installed?
If not, does anyone have any other ideas? My first thought was to disconnect the ASV and see if I can reproduce the issue. My fear is that if I'm right and the hiccup doesn't happen that I may damage something. Theoretically closing the throttle should end the event since ECU would terminate fuel injection, right?
