these motor are not as good i guess

is that #4 covered undser warranty if stage 2 is installled bu GM?

 

these motor are not as good i guess

is that #4 covered undser warranty if stage 2 is installled bu GM?

 

Blew mine beck in November https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/kaboom-38012/

 

on the 2 page -- what is Tech 2?

 

Tech 2 is a scanner that dealerships use, it hooks up to your OBD II port.

 

and what can it tell you more specifically. when it was last flashed and with what or code history? Please expand on this.

Bump for SATURDAY>>>>>lol

 

It can show the person who pulls up any code in the PCM's history a snapshot of every other sensor's reading at that time. A tech who knows what hes doing can figure out your MAF airflow and know how much air was coming into the engine at the time. (pulley)

 

well just got done pulling the pistons and number #4 was the cause. there is a lip right below the top ring and it is partially missing which would expain my blow by at high boost. Thankfully there was no damage. Now I just need to hone and put in the new pistons/rings, and wait for the clutch to come in and button it all back together again.

 

i guess i am joining the ranks of the blown motors. havent got the engine apart yet but it sounds like a cammed v8 and is smoking like crazy. on a brighter note i still dont have a check engine light. woo hoo?

 

sorry to hear you have to join the rank, i am going to go out on a limb and say cylinder #4like the rest of us.

 

is that your c urrent modifications in your sig?

fuel pressure maybe something that should be monitored? we may tune it bang on,but if the fuel delivery system falters a bit or starts to be inconsistant then look out.

did evryone run a wide band all the time who blew up? do you know the afr was good? should a wideband be run on cylinder #4? is there any way to check fuel pressure variance to each injector? fluid in theory is dynamic. pressure should be the same across the board. what would cause supply to cylinder four to be any different?

 

I wasnt running a wideband for awhile, then i finally got one over the winter and installed it then went to the dyno and that is went it popped, i was running 11.5, and no kr.

 

mine blew. cant find my thread containing it. it was replaced under warrnty

 

I was running 11.8 with no KR when mine went as well. Those are seemingly perfect conditions, yet the pistons breaks, just shows the sheer weakness of the stockers.

 

Hey Blown. I see a broken piston in your avatar. Maybe you posted full sized pics earlier but I missed them. I'm curious to see how they are breaking. Nobody else seems to be posting pics of their failed pistons either. Would you mind putting some up?

Thanks

Pierre

 

ya those are my current mods. no i dont have a wideband (i know stupid me but money is tight) but the guy that tuned my car was actually looking at it in hptuners when it went and it was reading a good afr and no kr

 

my #4 looks like it broke in the same spot, just not as intense as yours. It will make a nice ashtray if it drives me to smoking getting this thing done lol....

 

HP tuners doesn't read AFR without a wideband. I know because I use Steves computer to tune my car.

 

how the heck can a program made to tune a car no have a afr setup in it? that just doesnt make sense to me. o well it is what it is i guess.

 

ok got a alittle brain buster for ya. i believe i have a blown lsj or a clogged cat. i have the wrx exhaust note, NO smoke other than some of that normal black at WOT. took it in and had the injector seals replaced under warrenty. guess what the # 1 and 4 seals were toast. they then replaced my MAF under warrenty and also put back in my stock intake and reswapped it for the k and n i have had in cause they found out it wasnt the problem. but still a cammed exhause note. and now a hesistation after 5.5 and overbost by 6 k(18 to 19) for sure.. and its a stage 2 lsj.. what gives

 

Take it in to the dealer... see if you can get them to do a cylinder leak down test.

 

have had it in the dealer for 3 weeks + for the injector seals which should have fixed my concern. it didnt. they now jus plain dont want to work on it..and tell me to go to a different dealer.. and its the dealer i got my car from..and the other one is like 60 miles away..

 

WHat were your mods at the time?

what were your mods at the time?

no wideband is not stupid. you tuned with a wideband. I have it all the time just incase when I tune somthing happened to throw it off. Some people could say we should haf a wide band on each cylinder. there is specific equipment for doing that. But for a trained and knowledgeable tuner this is not a problem. if you are competent in your tuning then you can set it and forget it.

He went for dyno which most likely had the AFR on it.

HPTUners is capable of doing Actual AFR but you need to buy the wideband. it is easier when you purchase the enhanced version of HPT but it can be done with some McQivering to get the AFR readings.

LM1 or AEM is the easiest to get to work with HPT. I have a Autometer guage to match existing stock boost guage. will let you know how well it works.

EDIT: Well it looks like that a tune is not at fault for problems so far. weak pistons are weak. some are said by owners to be a bad tune but maybe not. I would like to get more specific info from those who posted. this is what I want to know.

what cylinder failed? #4
What was your AFR? better than 12
Most importantly - What are your mods at the current time and how long did you run the car with it and boost PSI level?
What mods did you run with last and for how long did you run with it and boost PSI?


To break a piston like this takes time. it has to begin cracking before it lets go. Just trying to figure out what PSI or mods that push it over the edge. perhaps 2.6 should not be run with stock pistons. 2.7 the max? safest is 2.8? 2.6 without full exhaust mods is a no no? lets find the common ground and warn others.

 

I was running, wideband, catless dp, 3in exhaust, front mount and stock heat exchanger, dual pass, additional surge tank, 60lb injectors when i was on the dyno. Apparently robs tune has section that leans out real bad at wot I was running this tune before the dyno run for several months. I was running a 2.6 last fall with no cooling mods ouch. I just replaced the pistons and ring and two of my four piston were shot. Piston had a very small section of the ringland gone. and the other piston when I was taking the rings off a chunk came out of it lucky I got the problem before the devestation happened. I am so paranoid now if I want to continue to run the 2.6 or not I dont have the money to be replacing pistons again. I did replace with diamond forged with dual coatings and total seal rings

 

^^^ Quick question, did you hone the cylinders at all? Or just toss the new pistons and rings in?

My #4 blew a ringland while tuning. AFR was 11.77. Currently working on getting a return fuel system made.