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- Thread starter LLBenJ
- Start date
TrumanBurbank
Member
Try disconnecting the bottom line on the big round actuator. I was having a similar issue, where I was only seeing 4psi max. Disconnect that line and I got 14+.
At least that will tell you if it's a boost leak, or the actuator releasing boost pressure.
baustin
Well-Known Member
I never had a chance to drive my donor, it was wrecked when I bought it and had broken 1 CV axle so it had no drive possibility. If you've already gone past some of these things just ignore them, I'm not sure how much you've looked over your donor exactly.
The smell of burnt rubber: is your parking brake sticking on 1 or both sides? Not if the handle is released, check by jacking up the rear axle and spinning the wheels by hand with the parking brake handle released. This could be a power drain and smell source.
The lines you now have in place match what I have on my 06 SS/SC, but are there any intake leaks? Does the brake pedal sink after starting up or does it stay rock hard like it would be when the car is off. I would think you could spray a light soap solution near any connections on the intake to look for bubbles, or make up a smoke machine (I think Ross and I have each made one for cheap, I can find a link if you need).
Seems very odd the previous owner removed the electronic boost gauge and went to a plumbed version, stock would top out at 12psi and I would hope the wires would still be present but I would guess the car didn't come with the original boost gauge, it was physically removed for the aftermarket one?
If it was clutch slip then you'd see the rpm's jump without direct connection to speed, I think this is the easiest since you can see this on the dash. I think the easiest test for clutch slip is to put it in higher gear at a lower speed and give it a good amount of throttle. I think I have that correct, I've never actually had clutches wear out on my cars so I can't verify.
Given that the car is a new purchase, how's the air filter? The supercharger might be fighting a badly clogged filter and causing a power decrease. Since it's in the front fender space it may have been neglected before.
Sure, the cobalt isn't as light as the goblin, but I do know you can still really feel the power of the SS/SC nicely throughout the rpm range. It should feel like a very solid torque curve throughout, just not quite as much acceleration as you'll get when it's in the goblin frame.
The smell of burnt rubber: is your parking brake sticking on 1 or both sides? Not if the handle is released, check by jacking up the rear axle and spinning the wheels by hand with the parking brake handle released. This could be a power drain and smell source.
The lines you now have in place match what I have on my 06 SS/SC, but are there any intake leaks? Does the brake pedal sink after starting up or does it stay rock hard like it would be when the car is off. I would think you could spray a light soap solution near any connections on the intake to look for bubbles, or make up a smoke machine (I think Ross and I have each made one for cheap, I can find a link if you need).
Seems very odd the previous owner removed the electronic boost gauge and went to a plumbed version, stock would top out at 12psi and I would hope the wires would still be present but I would guess the car didn't come with the original boost gauge, it was physically removed for the aftermarket one?
If it was clutch slip then you'd see the rpm's jump without direct connection to speed, I think this is the easiest since you can see this on the dash. I think the easiest test for clutch slip is to put it in higher gear at a lower speed and give it a good amount of throttle. I think I have that correct, I've never actually had clutches wear out on my cars so I can't verify.
Given that the car is a new purchase, how's the air filter? The supercharger might be fighting a badly clogged filter and causing a power decrease. Since it's in the front fender space it may have been neglected before.
Sure, the cobalt isn't as light as the goblin, but I do know you can still really feel the power of the SS/SC nicely throughout the rpm range. It should feel like a very solid torque curve throughout, just not quite as much acceleration as you'll get when it's in the goblin frame.
baustin
Well-Known Member
Should always be step 1.
Sluggonaut
Goblin Guru
I don't have any experience with the M62 or these cars, but as an SC guy (V8's and centri's) I would check the bypass valve's operation as part of a boost issue diagnosis.
While vacuum lines can cause problems between the actuator and the solenoid, either of those parts could be having problems too.
I'll leave it to those more knowledgeable of this platform to get into specifics, but I wanted to make sure this was discussed. Not sure how this relates to the burnt rubber smell, but definitely something to consider if you aren't seeing boost.
While vacuum lines can cause problems between the actuator and the solenoid, either of those parts could be having problems too.
I'll leave it to those more knowledgeable of this platform to get into specifics, but I wanted to make sure this was discussed. Not sure how this relates to the burnt rubber smell, but definitely something to consider if you aren't seeing boost.
TrumanBurbank
Member
Did you try disconnecting the lower line on the big round actuator? That valve controls boost pressure. Mine was doing the same thing and only made 4psi. When I disconnected the line I was making 14psi.
At least that will tell you if it's a boost leak, or the actuator releasing boost pressure.
At least that will tell you if it's a boost leak, or the actuator releasing boost pressure.
Rttoys
Goblin Guru
You'll find it sooner or later. Odds are its a very oddball case or something stupid. Hell, pull the charger off and see if the butterfly is even on there and functioning when you apply vac. This also gives you a chance to inspect the insides of the charger.
Well, pull the codes first if you are getting the check engine light.
Desert Sasqwatch
Goblin Guru
Not having any codes and having symptoms you described doesn't make sense.
TrumanBurbank
Member
I am having a similar issue, and it never tripped the check engine light. I haven't scanned for codes though as I don't have a reader.
The evap code isn’t a problem. The o2 code sounds like a readiness code for emissions testing and I don’t think is a problem. If there aren’t any codes it likely isn’t a wiring problem at the sensors. I think with the positive displacement super charger has to be making boost if its spinning fast enough. Either it’s bleeding boost off somewhere, it’s worn out and not making boost, the motor is completely worn out and can’t contain boost, or something is blocking air from entering the super charger. What I don’t know is exactly what the boost solenoid does on the SC cars.
Am I missing any options? On the LSA supercharger, the cooling “brick” inside can collapse and block airflow. Don’t know if something similar can happen on these cars.
Am I missing any options? On the LSA supercharger, the cooling “brick” inside can collapse and block airflow. Don’t know if something similar can happen on these cars.