Overboost event - how to know if something has gone wrong?
#1
Overboost event - how to know if something has gone wrong?
I've been diagnosing why I am only getting 3-4 PSI at present, and I determined it to be the wastegate actuator... done by removing the actuator line from the system and seeing what happened...
Well - it's definitely the actuator - I tested it lateish last night after dinner, and I was taken completely by surprise at how quick it spooled up - it was near immediate - I was watching the AFM/boost gauge closely but as it shot up so quick (can't recall the peak) she hit the lean mark for a fraction of a second, and as I lifted off immediately the boost both popped off a silicone hose joiner (I presume in addition to/alternative to opening the BOV), which obviously made it run like a pig - I discovered what had happened after I limped the couple of hundred metres into my home garage. I reconnected all the hoses and started it again - it idled and still idles perfectly. I also pulled plugs 1 & 3 to have a look - obvious signs of carbon buildup (like fine black soot) on them (running rich on normal boost) but no signs of scorching or anything I'd expect to show something wrong.
I also drove the car again this morning under normal conditions, and it all seems fine - idle, running, boost, temp, oil temp and pressure.....
Should I be concerned, and what should I look for specifcally that would indicate signs that I broke something significant/ly? I'm (understandably) a little skitzed out by it - just finished the install and the LAST thing I want is to break it.
And yes - I knew/know about being careful with this disgnosis method - it just took me completely by surprise.
Well - it's definitely the actuator - I tested it lateish last night after dinner, and I was taken completely by surprise at how quick it spooled up - it was near immediate - I was watching the AFM/boost gauge closely but as it shot up so quick (can't recall the peak) she hit the lean mark for a fraction of a second, and as I lifted off immediately the boost both popped off a silicone hose joiner (I presume in addition to/alternative to opening the BOV), which obviously made it run like a pig - I discovered what had happened after I limped the couple of hundred metres into my home garage. I reconnected all the hoses and started it again - it idled and still idles perfectly. I also pulled plugs 1 & 3 to have a look - obvious signs of carbon buildup (like fine black soot) on them (running rich on normal boost) but no signs of scorching or anything I'd expect to show something wrong.
I also drove the car again this morning under normal conditions, and it all seems fine - idle, running, boost, temp, oil temp and pressure.....
Should I be concerned, and what should I look for specifcally that would indicate signs that I broke something significant/ly? I'm (understandably) a little skitzed out by it - just finished the install and the LAST thing I want is to break it.
And yes - I knew/know about being careful with this disgnosis method - it just took me completely by surprise.
#4
Stock pump, 1.8 injectors, and EMB with tune set up for 8psi plus O2 clamp
But yes - everything seems OK - no obvious issues on a decent length run this morning.
#7
Arthor chill out dude . you probably didnt even top 8psi get a real WG and make sure the it is installed so that the actuator is pulled shut. Also i doubt you did anything to the turbo itself, if motor damage is your concern then run a compression check and maybe a leak down but i doubt anything is amiss. GL. FWIW i did the same on my motor to see if i had WG issues and seen 23 psi and no failure this was before my dyno runs and with stock fuel system and RRFPR. Sometimes you just get lucky.
#8
Boost Czar
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With just an open boost line to the actuator, you are slowly opening the wasegate...even at 1psi, so the turbine spool is negatively affected.
This is why I always advocate MBCs. Even at the same boost level it's going to force the actuator to stay closed as long as possible....giving you better spool.
This is why I always advocate MBCs. Even at the same boost level it's going to force the actuator to stay closed as long as possible....giving you better spool.
#9
Thanks guys - my sense of chill is restored
I checked the turbo fins, the plugs, and looked down the sparkplug shafts inside the chambers last night - all looks good - the plugs are clean again - no huge build up of soot (NGK Iridiums), so I guess I got lucky too - just that everything I have read about boost+lean=bad+breakage.
Then again - the BP motor is a tuff bit'o'gear.
And explaining to the g/f that I've just spent a huge amount of our money on a turbo kit only to have to spend more cause I broke it would have been bad - very bad.
I checked the turbo fins, the plugs, and looked down the sparkplug shafts inside the chambers last night - all looks good - the plugs are clean again - no huge build up of soot (NGK Iridiums), so I guess I got lucky too - just that everything I have read about boost+lean=bad+breakage.
Then again - the BP motor is a tuff bit'o'gear.
And explaining to the g/f that I've just spent a huge amount of our money on a turbo kit only to have to spend more cause I broke it would have been bad - very bad.
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Mikel
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09-28-2015 04:46 PM