QuickSilver_SS

So this is a bit of a different problem than the sensor itself I would think. Lately over the last few weeks everytime I go above say 15 psi. I am constantly needing to remove my upper map sensor and clean it with throttle body cleaner. It doesn't seem to be overly dirty at all. And nothing noticable seems to come out of it as far as oil. The reason I say I need to clean it after every pull. Even a short third gear pull is because after I do the pull. On my boost gauge at idle it doesn't not read at the same 70 Kpa vacuum. It reads 60 kpa. And the car acts a bit weird at part throttle. Like it surges lightly at only part throttle. I can hear it partly real ease boost. And then hold it. And then realise a bit of boost. It's a weird cycle. As well as the boost gauge being off it's normal vacuum reading.But as soon as I clean the upper tmap sensor with tb cleaner. The boost gauge reading goes back to its normal 70 ishikawa kpa reading and it does not have any part throttle boost weirdness until the next time I even go about half to three quarters throttle again. Then I need to clean it again. At wot it seems fine. The car has nearly 130k miles. The valves where just cleaned a few months ago with a new main gasket and PVC valve at the time. As well as new plugs. The compression is 160 psi on all 4 cylinders. And the car works great and pulls hard. Just is very weird to have to ALWAYS clean the upper tmap sensor after every time I go almost wot. Also.. I just replaced the tmap sensor itself 2 days ago as well as put a new proper sized o-ring on it. Any thoughts ?

63 Nova SS

iTrader: (3)

What about the lower one?

QuickSilver_SS

I have never cleaned the lower one. It is siliconed in place and would be a total pina to take out to clean. on another note I boost leak tested it. No leaks. its such a weird issue. I barely touch the throttle and the car acts like I almost floored it and lunges forward and then instantly as soon as it starts to over pull it stops and accelerates at the small amount I am pressing the gas .

63 Nova SS

iTrader: (3)

That is weird. Have you got a turbo seal leaking?Any oil in the charge pipe?

QuickSilver_SS

I don't appear to have any oil in the charge pipe itself. However I am starting to wonder about the new PCV valve I put in a month ago when I cleaned my valves. I wonder if it is sticking open under boost allowing way more oil then normal into the intake manifold. That's the only thing I can really think off. I remember John Powell saying in an old post way back in the day that he had saw several pcv valves stick open under boost causing constant oil into the intake manifold. I wonder if that is what's happening to me? It's a long shot.. cause the pcv is brand new. But you never know?

QuickSilver_SS

So driving to work this morning. The best way I can describe what it's doing is it really sounds like the recirculation valve on the turbo is opening up too early at just even barely any throttle bleeding off the boost. I don't know if it is ripped. Or sticking open. Or the spring is weak. Or if it is bleeding boost at even just barely pressing the throttle because of a bad sensor. But I can hear the boost being realised at even just part throttle when it shouldn't be doing that at all until I let off the gas. That's why it feels like it wants to take off and then stops right away. The boost is bleeding out due to the valve OR the solenoid opening too soon. Why though idk.... I don't have any boost leaks that I can find.

63 Nova SS

iTrader: (3)

Is the turbo surging at all?

QuickSilver_SS

I don't think so... I don't seem to hear it surge at all. But its bleeding boost at light throttle for some reason. And when I let off the gas the bypass valve that normally kinda sounds like a blow off valve. Well it barely makes any noise now at all. But if I go wot. It seems to be more normal. I have a bad pcv. Causing the tmap in the intake mani to foul with oil in one pull. Or I have a bad solenoid or ripped bypass rubber in the valve itself. Or weak spring in it. I just don't know which... or if it is something all together different .

QuickSilver_SS

So to date I have cleaned both the lower and upper t-map sensors. Checked the bypass valve, And checked for any boost leaks in the car. Which was actually hard to do because at 20 psi it keeps blowing my tester out of the charge pipe. It really doesn't sound like there are any leaks. Unless there is a small leak in the intercooler itself. My fuel trims are about -3.94% right now. I just cleaned the valves and replaced the pcv valve. As well as cleaned my kn filter on the intake. I really cant figure out what's going on with the car. When I give it part throttle and let off the gas. The Bypass valve barely makes a noise now at all. Sometimes none at all. I have to get it into boost to hear it at all. And even then it just doesn't sound the same as it use to. I have taken it out and it looks good. There are no tears and or cracks in the rubber. The spring seems fine. Maybe the Bypass Solenoid on top of the intake itself is gone bad ? Any thoughts and or suggestions. The car just feels a bit off. But the sound of the bypass valve is really weak and barely there. Unless I floor it. And even then it just sounds different.

Any thoughts ?? Anyone ? Thanks

63 Nova SS

iTrader: (3)

I'm near as good as this as some because I haven't experienced it, but have to tried to bypass the vacuum tank yet and just go straight to the manifold? Might help you narrow it down if it's the wastegate valve or the one on the intake. I don't hear mine much at all at part throttle, wot sounds like kicking a dog.

QuickSilver_SS

I'm kinda stumped. In the 7 years I have owned this sstc. It has been rock solid. I bet in the 7 years I have spent less then a grand in repairs on it. It's been so reliable. This is the first problem in have ever really had. I deleted the vac tank a few years back. As for the bypassing the manifold. I'm not really sure which line I would use off the solenoid to bypass it. As for the one on the intake ? Do you mean the line that goes into the k&n intake ?

63 Nova SS

iTrader: (3)

No you already deleted it, it sounds like. It would not surprise me if it wasn't the pcv valve, gotta be the flimsiest piece of crap I've ever seen. You don't have oil in your charge pipes so I can't see it's the turbo. What makes the car run bad is coating the top map sensor with oil, that's your root cause. I would pull the intake and replace the valve, but that's just me. If it's not smoking and doesn't have oil pre manifold i would think the turbo is ok. The issues you are having with the bpv/wastegate seem to be related to the oiled up map sensors, correct?

QuickSilver_SS

That is correct... there is no oil at all in the charge pipes. And none really at all on the turbo when I took the intake tube off to look in it. There was a bit of oil in the intake manifold. But not that much really. I have changed the pcv about a month ago when I walnut blasted my valves.

63 Nova SS

iTrader: (3)

I have a Powell oil separator so I have never had this issue. My guess is whatever is causing the oil blow by/oil accumulation in the intake is messing up the map sensor, which in turn is causing the wastegate issue.

QuickSilver_SS

Makes sense... Where is our waste gate ? On the turbo I assume ? I wonder if it isn't going bad itself. its almost like at part throttle its opening, closing, opening , closing and so on. Untill I let off the gas and or give it a bit more gas. Then its all fine. Could be the upper tmap being oily... But idk.... there isn't really that much oil in there per say. Not like what I have seen in other cars.

63 Nova SS

iTrader: (3)

Yep. Actuator is under the turbo and the control valve for it is under there too.

QuickSilver_SS

I wonder if that's my issue. Or the bypass valve solenoid on the manifold.

63 Nova SS

iTrader: (3)

Cold be either, try pro race.com the valve for the wife is the same as a k04 and it's cheaper through them.

QuickSilver_SS

Thankfully I was able to get it fixed yesterday. Turns out my bypass valve solenoid was bad. Who knew... I don't know if it was sticking open. Or sticking closed. Or just failing all together. But I picked a new one up from my local gm dealer. And the second I started the car I knew it was fixed. Because strangely enough my boost garage was finally sitting back in its normal spot at idle in Vac. And the bypass valve is now back to being loud and crisper sounding then it has been in a long time. My fuel trims even dropped back down from -4 to -1.5. The car drives all the way around better now.

63 Nova SS

iTrader: (3)

Glad you got it figured out.

QuickSilver_SS

Me too ! To be honest I was only guessing when I picked the bypass solenoid up. There where no cel. And I was just going off a friends advice because his went bad in his 2010 ss/tc a few years ago and he said it sounded like the same symptoms as his had. I got lucky. Thankfully. Thank you for helping out and responding. As an O.G member. Sense 06 but lurking sense 05. I remember how active this board once use to be. I'm sure a lot of people have moved on to other cars and some of them are even scrapped by now. Thanks for the input.

63 Nova SS

iTrader: (3)

Yeah about the only forum that's active is the daily work chat. A lot of experience in working on these cars is now gone with people moving to other cars. Enjoy!

umrdyldo

iTrader: (1)

Back when I had this issue, it was the wiring to the upper MAP sensor. Even though it clicked in, I could go push in the connector harder and the car would idle perfectly.

Drove me nuts. Not sure if a rewire was needed or could have just zip tied it.