ecarse Posted May 22, 2011 Share Posted May 22, 2011 I'm getting my wife's 05 LGT wagon tuned by Shamar to try to address a chronic overboost, and he thinks there's a mechanical issue that he can't 100% cure. He's never seen it before and wasn't sure where I should look, so let's see what the LGT hive mind thinks. Prior to the tune, the car was giving a wastegate solenoid code under 3/4 throttle and higher in 3d gear and up--basically whenever the engine was under heavy loads. Shamar has been trying to tune that out, but said compared to normal Stage I LGTs my car is "spooling a bit slower and the boost is creeping on its own". Even after the third tuning iteration, the car is still giving overboost codes on my data logging runs, albeit less easily than before. The car has 95k, and is 100% stock, not even a panel filter. Between the error codes and the poor boost control, could my wastegate be leaking @ low boost and failing to open @ high boost? What are some theories? Link to comment Share on other sites More sharing options...
STIBungy Posted May 22, 2011 Share Posted May 22, 2011 If you suspect its the wastegate, you could take a bicycle pump with a gauge and stick it into the wastegate and see if its opening up. Then you may have to pull the downpipe to see if its seated all the way down or if the turbo may be cracked and leaking. If you suspect the solenoid, you could run a line from vacuum straight to the wastegate and see how how quickly boost builds from there. It should only boost up to .5bar. Link to comment Share on other sites More sharing options...
ecarse Posted May 24, 2011 Author Share Posted May 24, 2011 If you suspect its the wastegate, you could take a bicycle pump with a gauge and stick it into the wastegate and see if its opening up. Then you may have to pull the downpipe to see if its seated all the way down or if the turbo may be cracked and leaking. If you suspect the solenoid, you could run a line from vacuum straight to the wastegate and see how how quickly boost builds from there. It should only boost up to .5bar. Thanks for the ideas. I'm definitely going to check the wastegate and actuator. I'm wondering if could also be a leaky vacuum line from the intake side to the solenoid or actuator. If the solenoid were faulty, wouldn't I just stay at low boost, limited by the wastegate actuator spring's rate? Wouldn't the solenoid just let all the boost pressure push on the diaphragm and open the wastegate early? I'm still learning the system here, so I'm just confirming that my understanding is correct. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.