I just found a holy jesus decent size boost leak around the tmap sensor on the lower charge piping. Its enough I can easily feel the pressure leak around it !! I wonder if that would cause my out of wack ltft and stft's. As well as my lack of power lately in the bottom end . But how in the heck do I fix a leak down there ? The seal is green, Is that the right seal ? Maybe I could try silicone around the sensor. If so , what kind ?

Also what can I clean the tmap sensor with ? Throttle body cleaner or maf cleaner ? I have both , so I was wondering which one would be best ?

 

You need a black 202 o ring I do believe on it. What I did on mine is siliconed it and put a different screw in to hold it down.

 

I reused the screw . But I did use some high heat silicone sealant on both the base of the sensor itself as well as around the screw with a o-ring seal I found around my house. It fits pretty good. I hope it works. Im just letting the silicone set up and get tack free for an hour before I check to see if it is leaking anymore.

 

Very easy fix, I had same one. Bad oring, couldn't find an oring so here is what u do, put silicone around the oring and put in sensor, let dry over night, will hold better than oring did. Been on mine 2 years with no issues

 

Yep , I am in the process of doing that right now. I finally got my lower cp off and took it into the house. I silicone it. I hope it holds. And I also just realized that the top map sensor is also leaking air around it. The green o-rings must not be the right ones. the sensors are really loose in the holes they go in. The o-rings are not sealing at all. They did a really poor install job of my stage kit at the gm dealer. They must have both been leaking boost sense I first bought the gms1 kit just over a year ago.

 

use maf cleaner make sure its unplugged and completely dry before reinstalling and cycling key

 

trust me it will hold

 

I used a dab of sealer on the screw as well. My o-rings are blue as they should be according to this thread-https://www.cobaltss.net/forums/how-guide-43/how-install-gm-stage-1-lnf-kit-gms1-267728/.
The link to the CED replacements shows them as black; maybe someone comment on the correct size.

 

I would love to now what color the seals should be? There is no way the green ones on my sensors are right. They are so loose its ridiculous. But do i need the blue ones or black ones.

 

O-RING 3 Bar Map Sensor 12626998

From what I read, the older GMS1 cobalt o rings came as blue but now come as black. My car had blue and they appeared to be the same as the black ones. I replaced them anyway to be sure. Green color is definitely too small for our cars.

Get 4. You need 2 but it'd be a hassle to have one break on you and then order more. I used vaseline and did not break any.

They are much bigger than the green ones that come on the sensors. I think someone was saying those are for HHRs or another vehicle.

 

Thanks for the link. I will probably orde some if them to have on hand. On a side note.. inlet the silicone dry for 31 hours before I even started the car. I really wanted to make sure bit was totally dry. I know this is going to be a absolutely stupid question. So I will put on my flame suit. But with my car leaking boost in two places. Both sensors. How much do you guys think that would effect the performance of the car ? Any that the butt dtno would feel ? The car seemed like it would be at about 18 psi before this. But I would think the charger was spinning faster then it needed to to compensate for the leak. I'm just wondering how much fixing the two boost leaks will help the power of the car. As well as km sure this is why my fuel trims were a bit off.

 

I had a leak at my lower tmap and my car bogged like ****, ran like **** and the boost was sporadic...but I had a major leak.

I had to eventually buy a new Tmap from CED cause the old one was ripped and the silcone would not hold the 26 psi spike.

 

I assume you are spiking 26 psi due to the term tune. I am gms1 tune only. I typically only see 18-20 psi max. So I'm pretty sure that the silicone will hold. I let it dry for 30+ hours. It hardens and sticks like crazy glue !

Now I just have to start and monitor my fuel trims over the next few days. I bet they have started to and will continue to level off and stabilize.

Also , are the two 3 bar sensors the same sensor ? With the same part number ?

 

Well after two days I have re-checked the boost leak. And the top sensor doesn't seem to be leaking anymore. But the bottom one still seems to be leaking a VERY small amount. It probably sealed about 90% of the way. I put a bit more silicone around the sensor to see if I can get it to seal all the way. I seem to be hitting a max of 140kpa (20.5 psi ) if that is about right for gms1. I didn't disconnect the battery. Should I have to reset the computer ?

 

To reset the trims you need to unplug the battery. I would do so. 20psi is about right for GMS1 as that is what I get.

I would still order the correct Orings.

 

Strangly enough , my ltft is sitting at 0.0 after a day or two of driving. I'm sure that will change. But it surprized me none the less. My stft has become a little more stable. There arn't as many high's and low's in the stft as there use to be. And when there are a few hig's and low's they are only half of what they use to be. Instead of seeing a high and low of -8% to +8% ish I now only see about -4% to +5% ish.
The car definitly has a lot more bottom end power to end and seems to spool faster now. But I still might have to break down and order a few proper seals and at least one new 3 bar sensor. Becasue I have no idea if I will be able to get all of the silicone off of the sensor to reuse it !


Here is a picture of the GHETTO fix for the time being !!