just like the title says, i think i blew the motor up last night...
heres the story, i was out last night driving the car running 12 psi (would spike to 14 because of the cold weather) and i gave it one really hard pull. i ran through 1-3 and by the end of it i heard something that sounded like metal rubbing together. i put it in nuetral and the car stalled out on its own. i tryed to start it again but all i got was cranking. we pulled the egi fuse and tryed to crank it over, but nothing. so i got it pushed started and it actually started....but i had to stay on the gas or else it would want to stall out. well i limped it back to the shop and the whole way it felt and sounded like i was running on half a motor. also the boost gauge needle was shaking pretty bad so i thought that the turbos might have blown. well when i got to the shop my power fc said that my trailing plugs where only reading 6-7 when cranking the engine so that might be part of it too. well guys im FREAKING out on what could be wronge with the car and would really appreciate any input on this whole thing!

 

check map sensor....probably blown. Rule of thumb never run more than 10 psi on stock ecu

 

It amazing how many blown motor threads you see during the years first few solid cold fronts! If it is not a map sensor issue good luck. Compression test time. G

 

you said boost "spike", but it sounds like creep....spike isn't caused by cold weather, generally speaking

another motor down the tubes because someone was too cheap to port the wastegate (and yes I am guilty myself).....DON'T DRIVE YOUR CAR IF YOU HAVE CREEP (LOSS OF BOOST CONTROL), IT AIN'T WORTH IT

 

the map sensor is a good idea to start with. also im using the power fc tuned to 12lbs of boost. any ideas on what that scraping sound might have been? sorry i know its a little vauge..

 

Sounds blown to me. Get a compression check to be sure. How close are you to NJ? Bring the car up to me and Ihor, we'll give you a stout streetported motor. PM me if interested.

 

does anybody think it might be the plugs??

 

No. What are your mods?

 

Don't waste your time trying to diagnose the issue before you compression test. Just do the compression test first.. then go from there. Take it from someone who has a few under his belt, as I am sure many of us do LOL.

 

sounds like a blown engine unfortunately...

 

comp. check!

 

+1, that's what got me.

If you wanna play, be ready to pay.

 

what exactly is creep by the way? i always thought it was the same as a boost spike, but im assuming im rong, lol ive learned alot in my past year of ownership, but dont know everything yet (im working on it )

 

It's where the wastegat is 100% open, but it cannot allow enough exhaust to bypass the turbo. So the higher the RPM, the more exhaust is output, thus the "creeping" boost. It'll creep up the higher the RPM, and you'll have unwanted, and uncontrolled boost.

 

so if my boost pills removed because of boost spikes (streetported motor) and its boosting strictly off the wastegate (6psi i believe) do i shouldnt have to worry about that should i? i dont have a boost gauge hooked up yet.

 

Yes, you should worry about it. In the past, I would have my boost controller off, meaning 7 psi boost. I'd still creep to 15 psi on cold weather.....from 5500 to 8000 or so the boost would skyrocket. this was with open exhaust and stock wastegate. If people would leave a cat on the car, they wouldn't have these problems.

 

yeah brah, i know alot of people that pop thier engine from straight pipes and a non ported wastegates. this almost happened to me when i first got my batmobile, i bought straight pipes and when i did a 16psi boost take off with a stock ECM, i litterally drove home to put my stock cat back on. thank goodness i did not hear a pop or anything... but now i think i have a chipped apex seal (hence why i am ripping apart my engine to see). i am 23, getting my PhD in aerospace engineering and am a material control supervisor for a squadron in the navy and i am still learning about this car :-D

it sucks people have to learn the hard way when they dont have a boost gauge

 

the boost gauge won't necessarily save you because you can't react that quick

to run a mp safely you need

1. ported WG
2. reliable boost control
3. plenty of fuel, and preferably
4. wideband AFR

 

ive got a highflow cat on there. no boost conroller as of yet. so ive got the fuel coverd. but the waste gate i dont think was ported when they did a streetport. i run my motor fairly hard on ocasion doing 35 mph pulls just cause i get bored. (a couple in this cold weather) my motors been shaking horribly at 1200 rpm, lol but i have my own thread started about that so i wont hijack this one with questions about that, but i found out what i need to know about boost creep. bassicly need to just go single and have a half way decent wastegate and simplify the crap outa my car. thats if my motor isnt blown. if thats the case ive got an ls2 in the carport. build that up and go that way for my daily driver and do a 20b project when i get extra cash. thanks for the info guys

 

If it's a stock ECU, it should fuel cut at 12psi if there is a boost creep problem. If it's a spike the stock ECU can't do anything about it.

In any case, it's yet another person losing an engine to too much boost. So sad.

Dave

 

Why would your boost gauge needle be shaking if your turbos were blown? Unless you were actually boosting on them that shouldn't be the cause. More likely, the shaking needle is because your engine is having a really tough time holding good vacuum (I'm assuming the shaking you observe is during idle conditions)... ask me how I know Like everyone else said, comp check!

If you can't control the boost, then don't boost!

 

I see this happen every year once the weather cools down. Sad stuff......

 

The violently shaking boost gauge is a tell tail sign of a compression issue

 

it should, but mine didn't (twice)....creep can kill the motor before fuel cut kicks in, and fuel cut itself can exacerbate the problem

retarding the ignition would have been a better approach imo