thejazzcat Posted January 22, 2017 Share Posted January 22, 2017 Hey all, I am thinking I MAY have a vacuum leak or something going on with my 05 LGT. Basically I was taking a left on to an empty road and went to boost midway through first and shifted to second. Somewhere between when I hit boost in first and when I shifted to second, there was a sound like something popping off under the hood. Not loud, but distinctly not a normal engine sound. From that point on, my boost levels were toast. I could get almost up to positive boost, and then I would see a sudden drop in boost levels. I drove very conservatively home and felt a lack of power most of the way, with the exception of a few minutes where boost returned slightly and I got up to 3 psi or so at peak with no sudden boost drop off. When I got the car home I tried getting it in to boost by revving it in neutral. Almost hit 0 psi at redline, though the engine did not seem happy about it (got a strange torque twist from the front of the car that I have never see before, sounded louder than usual). Not knowing where to look I popped the hood and simply looked around for problems. From topside I noticed: - The intake directly above the radiator seemed pretty hot (the hood stand was hot to the touch when I went to put it up). I should have been monitoring coolant temps on my Cobb but I did not. The stock gauge reads normal. - front drivers side of the engine block had oil on it, right around the grey plastic coil packs for the spark plug. I could not discern if it was coming from the spark plug cavity or from the oil fill tube directly above it (I did have a recent oil change). things I noticed on the bottom side: - nothing that I could tell without pulling the exhaust and checking the gaskets etc. Questions: So, what would be the next best step here... Given the symptoms, what do people suggest I start checking? Also, is it safe to drive the car without boost briefly like to and from work 10 min away? (It seems like it drives ok, just underpowered). Thanks everyone for your insight. Ron Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
HDTurbo Posted January 22, 2017 Share Posted January 22, 2017 No CEL? Check that your throttle body hose hasn't loosened/come off, that would account for the pop and lack of any boost. Second, check under TMIC for a vacuum line having come off. Link to comment Share on other sites More sharing options...
thejazzcat Posted January 22, 2017 Author Share Posted January 22, 2017 No CEL? Check that your throttle body hose hasn't loosened/come off, that would account for the pop and lack of any boost. Second, check under TMIC for a vacuum line having come off. Nope, no CEL (i assume the Cobb wouldn't be preventing the dash CEL from coming on for non suppressed errors?). The throttle body hose seems like a good place to check. Is the tmic vacuum line accessible or do I need to unbolt the tmic? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
HDTurbo Posted January 22, 2017 Share Posted January 22, 2017 Nope, no CEL (i assume the Cobb wouldn't be preventing the dash CEL from coming on for non suppressed errors?). The throttle body hose seems like a good place to check. Is the tmic vacuum line accessible or do I need to unbolt the tmic? Sent from my iPhone using Tapatalk I get CEL in these situations (both have happened) and I have an AP, which is what I assume you mean by Cobb. The suspect vacuum lines are under the TMIC so you may need to remove it, but I would start with checking whether the TB hose has come off the TB before unbolting from the turbo. Link to comment Share on other sites More sharing options...
MilesA Posted January 22, 2017 Share Posted January 22, 2017 You normally won't get much boost in neutral since there's no real load on the engine. Suspect throttle body connection also, though there are some vacuum lines under the intercooler that are know to come loose. Link to comment Share on other sites More sharing options...
whitrzac Posted January 22, 2017 Share Posted January 22, 2017 Throttle body hose Or Your wastegate arm came off. Link to comment Share on other sites More sharing options...
thejazzcat Posted January 24, 2017 Author Share Posted January 24, 2017 So the plot thickens here. I had to drive to a doctors appointment down the street and so I drove my car a couple of miles today. Strangely enough, my boost is back now! In fact I am actually now overboosting from previous numbers. I used to hit -2 psi below target or so, which I believe is spot on when accounting for the fact that I am several thousand feet above sea level. Now I am actually overboosting by about 1psi over target. So- since this problem seems to be inconsistent, I wonder if this is really a disconnected intake hose? Would a more minor leak more likely produce the inconsistent symptoms above? It is colder today than it was the other day when I started having problems, maybe one of the hoses shrunk enough to reseal? (I have not yet had the chance to pull my tmic and visually inspect the connections as people have recommended -but the more knowledge about what I might be looking for the better :] ) Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
whitrzac Posted January 25, 2017 Share Posted January 25, 2017 Then keep driving the car till it blows up completely. We'll still be here for support when you see the bill to fix it properly. Link to comment Share on other sites More sharing options...
thejazzcat Posted January 25, 2017 Author Share Posted January 25, 2017 Then keep driving the car till it blows up completely. We'll still be here for support when you see the bill to fix it properly. I m still working on fixing the issue, I had to drive it in a pinch. There's no need to be sarcastic here. You should actually read posts before you reply. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
gimpydingo Posted January 26, 2017 Share Posted January 26, 2017 I m still working on fixing the issue, I had to drive it in a pinch. There's no need to be sarcastic here. You should actually read posts before you reply. Sent from my iPhone using Tapatalk Welcome to the forums. The wild west here has tamed out a bit with the loss of some members, so that's not much sarcasm compared to how it used to be. Do as others suggest, checking the vac lines and TB hose. http://legacygt.com/forums/showthread.php/2005-2006-lgt-colored-vacuum-routing-diagram-143225.html Link to comment Share on other sites More sharing options...
05legacygt1994 Posted January 26, 2017 Share Posted January 26, 2017 Hello im new to this and not sure if im posting in the right place but im desperate for answers. I have a 05 lgt and pretty much stock . i have a issue were i barely get boost if i roll onto the gas slow but if i step on it quick or push more than about 7 pounds of boost it flutters/cuts out bad even sometimes trips my check engine light and my cruise control light. I also get no vacuum pleasure on my boost gage ever . have replaced all my vacuum lines and an curious if this has to do with my wastegate? Link to comment Share on other sites More sharing options...
thejazzcat Posted January 26, 2017 Author Share Posted January 26, 2017 Hello im new to this and not sure if im posting in the right place but im desperate for answers. I have a 05 lgt and pretty much stock . i have a issue were i barely get boost if i roll onto the gas slow but if i step on it quick or push more than about 7 pounds of boost it flutters/cuts out bad even sometimes trips my check engine light and my cruise control light. I also get no vacuum pleasure on my boost gage ever . have replaced all my vacuum lines and an curious if this has to do with my wastegate? You won't get much boost if you slowly accelerate, there isn't much engine load doing that. That sounds normal to me. As for stepping on it and cutting after 7lbs or so, that sounds like a weak wastegate actuator spring or a bad wastegate solenoid to me. I am fairly new to turboed cars though, so I may be off on my theory here. Any other members have input here? Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
MilesA Posted January 26, 2017 Share Posted January 26, 2017 ...i barely get boost if i roll onto the gas slow but if i step on it quick or push more than about 7 pounds of boost it flutters/cuts out bad even sometimes trips my check engine light and my cruise control light...What CEL(s) do you see when this happens? Have you disconnected your battery or has your battery run down recently? Link to comment Share on other sites More sharing options...
thejazzcat Posted January 26, 2017 Author Share Posted January 26, 2017 ... even sometimes trips my check engine light and my cruise control light. FYI (off topic but useful to know) - in these cars your cruise control light will go off anytime the check engine light is on, to make sure the driver doesn't ignore the problem. Since a flashing check engine light means catastrophic "your car go boom" failure, they found another way to annoy the driver in to taking immediate action for lesser problems. Gotta love all of the overzealous flashing lights and warning chimes Subaru used... Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
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