|
|
|
|
| Author |
|
|
Registered
|
intermittent smoke/surge sound under boost?
Hey guys. So I just got my 930 back from the shop, after having some things checked out and getting a good bill of health on the engine. While driving home, I noticed that sometimes, right as boost hits, and during boost, it'll blow a cloud of smoke and the engine will hesitate. The sound that occurs when this happens is similar to compressor surge I've heard in people's videos.
However, it only happens about 8 out of 10 times. The times it doesn't happen, it pulls hard like it should with no issues whatsoever. It doesn't matter if it's from a stop in first gear, or from a roll on the fwy. What does this sound like? My car: 83 euro, 45k miles with 3% leakdown, stock everything. |
||
03-05-2011, 06:36 PM
|
|
|
Got Boost?
|
Can you hear a loud hiss while driving besides a concrete barrier? To me it looks like you have a boost leak. Just went through a similar situation.
__________________
"The only motivation to make you go race after race, travel after travel, is winning. The possibility that you have for winning. If you don't have that, nothing else can make you work." -Ayrton Senna- |
||
|
03-07-2011, 03:40 PM
|
|
|
Registered
|
Well, i just took it for a spin and took a video.
There's no hissing sound next to a concrete barrier, i made a couple pulls. I dont know how well you can hear it in the video, but it's the best i can get. YouTube - 00029 |
||
|
03-07-2011, 05:45 PM
|
|
|
Registered
Join Date: Jul 2008
Location: Central Washington State
Posts: 4,421
|
I kinda think I can hear the hissing in your video. When it does this, and you blow clouds of smoke out the back, do you also experience a marked reduction in power and perhaps a stutter/miss or feeling like it's bogging down? If so, I'm guessing boost leak somewhere - which would cause an overly rich condition. Won't hurt the engine, but will rob it of power.
What did they do to it at the shop? If part of the service was to remove the IC or any associated turbo plumbing then I would take it back - tell them to find the leak - and make it right.
__________________
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, B&B intercooler, stock 3LDZ. |
||
|
03-07-2011, 06:05 PM
|
|
|
Registered
|
That's spot on!! It stutters, blows smoke, and makes it hard to accelerate. It revs fine without load...
The shop did a leakdown test, replaced the spark plugs, changed the oil, replaced my valve cover gaskets, torqued the heads, and adjusted the valves. |
||
|
03-07-2011, 06:30 PM
|
|
|
Registered
Join Date: Jun 2008
Location: Yamhill OR.
Posts: 456
|
More than likely they removed the intercooler to get better access to adjust the valves. It could of cut an o-ring or just slipped out of the groove. It sounds like there is a boost leak in the video.
|
||
|
03-07-2011, 07:34 PM
|
|
|
|
Tinkering Pays!!
|
Quote:
BTW: that is a lot of hissing in the video - - - like somenone is letting all the air out... 
__________________
LIVN80S - - Red '79 Porsche 930 Steel Slant Nose Conversion [in 1987] w. 46k miles 3.3L; 964 Cams; K27HF @ 1.0 BAR, with Garrettson Intercooler; Rarly Zork; CIS Flowtech Fuel Head & BL-WUR. Last edited by mooney265; 03-08-2011 at 06:06 AM.. |
||
|
03-08-2011, 06:04 AM
|
|
|
Registered
Join Date: Jul 2008
Location: Central Washington State
Posts: 4,421
|
Quote:
Clarifications always welcomed.
__________________
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, B&B intercooler, stock 3LDZ. |
||
|
03-08-2011, 12:07 PM
|
|
|
Tinkering Pays!!
|
yes, and I changed the oil 4X in 3k miles...
__________________
LIVN80S - - Red '79 Porsche 930 Steel Slant Nose Conversion [in 1987] w. 46k miles 3.3L; 964 Cams; K27HF @ 1.0 BAR, with Garrettson Intercooler; Rarly Zork; CIS Flowtech Fuel Head & BL-WUR. |
||
|
03-08-2011, 01:08 PM
|
|
|
Registered
|
Wow, i didnt even see all these new posts.
I havent had time to diagnose the issue or drive the car much more in the past week. Thanks for the heads up guys. Only reason I took it to the shop in the first place was to have it checked out because i'll be selling the engine soon. Bummer that it came back with this issue. |
||
|
03-13-2011, 03:33 PM
|
|
|
Registered
|
exact same thing happened to me when I had the PPI done on my car...
It was great on the test drive, had the PPI done and they installed ney o-rings... they broke one of them while reinstalling the intercooler... Thanks to that shop who charged me an incredible amount of money for a PPI, new spark plugs, wires, distributor cap and o-rings on the intercooler only to mess it up... It did exactly that and was losing boost not always but often enough... Don't read my new thread about my turbo though... I hope that you don't have the same problem as my turbo and that you only have the boost leak
__________________
David 1985 Black 930, K27 7006, Garretson Intercooler, Adj boost, TB: 23 - 31mm, bielstein sport shocks, ER polybronze bushings front and rear, ER monoball joints front and rear with offset camber plates, 935 X triangulated strut brace, raised spindles, racing bump steer kit 1981 Black 911sc (sold) |
||
|
03-13-2011, 04:00 PM
|
|
1977 Porsche Carrera 3.0 3.0 
turbo 3.6
Roadster
Porsche 930
Ford Truck
1981 Porsche 911 sc (sold)
1985 Porsche 930
