That's 3 that I've read about now counting mine last year. John (GMTech) wrote me and said he started popping popcorn in boost after a 3.5 sec 60-100 pull. Pulled the injector rail and found the (white) inj seal gone on #4 in the head and he KNOWS it was there when he put the rail on. Theory is once the seal develops a leak, they just burn away. Must be the case.

Hopefully the black seals solve the issue.

That is all.

 

thanks for the info!

 

Need to check mine

 

yup, seals just disintegrate if they fail, remember it seals into the combustion chamber.

 

Held seen two of them myself. Remember my old issue I had . This was it. And also a lnf I did work on for a dealership

 

I think my 60% E at 25 psi boost helped vaporize it. OEM white seals btw. I believe they have been upgraded, but lack specific info.

 

WOW this is timely. My sound is more like a clack/stungun sound, like I can hear the combustion, mainly under load and especially in boost. Ive got the black seals ready to go and checking them this weekend just incase it turns out to be the issue. Running a E blend for a long time probably ate them away not to mention that Ive had the injectors out twice now.

I was also able to buy the seal installer tool for real cheap so Im gonna use that to install them.

 

Whats the part number on the tool?

 

This is it here Kent-Moore EN-48266 Injector Seal Instaler / Sizer

But I found it on ebay for 30 bucks so I bought it. Cant ever have too many specialty tools

 

You NEED the tool to size the seals after putting them over the injector tip. Anytime an injector is removed the seals are to be replaced. I posted this many times before since replacing mine over a year ago.

Mine would pop any time I got into a slight amount of boost and would increase with load. I suppose it could be discribed as a gunfire sound. Mine sounded like it was coming from the drivers side by my feet though. It was #3. I swore it was in the exhaust but logged no misfires. Compression was only down slightly to 135-140 from 160.

 

Heres a 2010 Cobalt SS TC Fuel rail. Also listed for 2010 2011 SAAB Turbo

 

Add me to the list to. Pretty sure mine went to in 3rd gear around 6200 i get the rapid gun fire sound.

also on the picture about where is the seal that goes? So i know where to look and where can i buy new seals

 

Look at Mongo's pic. They are black near the tip of the injector. You might as well just buy 4 since they are not reusable.

 

Were all 3 running E mixes?

 

 

Hmmm with this seal gone you should hear a hiss when putting some air through the system via a boost leak tester correct? I ask because I have paintballerrs car sitting at my house waiting to go into storage and we have been trying to track down the issue.

 

Unknown by me.

 

Perhaps, but to be sure, I'd pull the intake mani and if the injectors stay in the head when the fuel rail is pulled, they are prob ok. My #3 injector came out with the rail and the others stayed in the head. Installed new seals on them all to be sure.

Mine only had issues in boost so it might seal at normal pressures and be undetectable at low psi like a boost leak test.

 

What do you mean by SIZE the seals. The tool does what exactly? Why is it different than just sliding the seal on there by force little by little? Im still unclear as to the 'how' to do this right LOL I need to take it off the car so I can make sense of the install procedure.

 

As the seal is placed over the injector tip, it stretches out and becomes loose in the groove and will not correctly install into the head. The tool is two parts, a tapered cone that goes over the inj tip to aid sliding it on and a cupped half that reshapes & sizes the pliable teflon seal once it is on the injector tip. You can see the seals in the pics from earlier posts that they are down into the relief in the inj tip. They are pliable but not elastic and have to be sized & shaped after getting them onto the inj tip.

There is a post earlier in the thread that links to the tool, I found one on Ebay for $20 last year but sold it when I sold the 'balt.

 

Ohhh I see. Cool. So it slides on with the aid of one of the pieces and then you use the other piece to basically 'mash'(Size) it into fitting flush on the injector.

 

Hi guys, figured I'd jump in here...

Yes, I've been running an E mix for about a year and a half, not sure that really is the cause of this failure though. I think the combination of marginal quality seals and high boost are the biggest factors. They obviously can be perfectly fine one minute, then completely gone the next. I did that 60-100 run, then drove about 10 more minutes on the freeway. When I was going up the overpass getting off the freeway, it made one loud pop, it sounded like it backfired through the intake. When I stopped at the first light, it idled perfectly smooth so I knew it wasn't that bad. Once I pulled away from the light and heard it more I realized it wasn't backfiring because it was running perfectly smooth with no misfires. The only thing that made sense was an injector seal leak. It's really easy to pull the intake and fuel rail on the Kappa's so I brought home the tool and a seal kit the next day and tore into it. I had the intake and rail off, all the seals changed, back together and running in about 40 minutes. The point is, instead of trying to do a leak-down or compression test, if you're getting the popcorn sound, just pull the rail and look. I think what happens is at high boost the pressure pushes the injector out enough to blow combustion past, but at idle and low cylinder pressures it seals somewhat ok.

The seal kit comes with all the seals for all 4 injectors. The tool is a must-have because it keeps the seals from getting damaged on install. The tool has a tapered bore so as you slide it over the new seal it compresses it down to the right size. After putting the seal on the injector, the seal will be too big to fit in the head and will most likely slide up the injector instead of staying in the grove.

It's really not that big of a job and the parts and tool aren't a ton of money either. I was actually thrilled it was just an injector seal on my car, I had made a couple changes on my engine and tune before that run. I was running about 30psi to 7500rpm, probably around 550 crank hp so something bad happening was definitely a possibility! The hella loud sound it makes when these seals go out is WAY worse than the problem actually is.

 

GMT - Thanks for finding the time to post.

 

Thanks guys for all the info! Prolly gonna pull the rail on the cobalt when Cody (the owner, paintballerr) comes down on sunday.

 

Injector Teflon Seal Installer Special Tool Kent Moore EN-48266 I bought this kit on Ebay for $19.50