Ian0611

iTrader: (41)

So I've run into a new problem recently with spool-up on my car. I've tried searching but haven't really found anything that describes the problem I'm having so here goes. I'll try to make this as short as possible.

Basically what happens is is when I go WOT boost will start to build normally until it hits about 20psi then stays flat at 20 for a second or two and then surges to anywhere from 25-27psi. This happens in every gear but is obviously more noticeable in 3rd, 4th, and 5th gear. The times that I've been able to log this, it seems to always happen between 3500-4500 rpm.

I went out today to do some street tuning thinking perhaps it was an issue with the tune and after doing a few runs and making some adjustments the problem seemed to go away. But on my way home from work tonight I tried going WOT in 3rd to make sure everything was OK and the same thing happened again. I drove around somemore and the problem seemed to go away after I did a couple more WOT pulls in 2nd amd 3rd gear.

So here are my thoughts on what the problem could be:

The Tune: I'm using ECU controlled boost but I may have posted this in the wrong section because I'm starting to think that it's not the tune, but I'm still not 100% certain on that. I've tried several different settings with my boost and I'm still having this problem and the last time I made any adjustments to my boost tables was at least a few weeks before this problem showed up.

The BOV: I have a metal IX BOV that I bought new and installed in February so I'd be surprised if it were leaking or having other issues already but anythings possible. I have a couple of other issues (car goes really rich sometimes when coming to a stop) going on that could be related to the BOV so that's why I'm wondering if this problem could be related as well.

The turbo: I'm still using the stock 8 turbo with a 10.5 hotside and the car has 80,000 miles on it so maybe it's starting to give out.

Stock boost solenoid: It's also been on there for 80K. Maybe it's time to upgrade to a Grimmspeed 3 port or something.

Stock WG Actuator: ???

I don't really want to go out and buy a bunch of parts that I don't need that won't fix the problem so any thoughts and help would be greatly appreciated!!

white8

iTrader: (14)

I had this problem on my 8 turbo with 9.8 side with 77,000 miles My boost was set at 27 psi and it would go 24 psi pause 35 psi! I kept driving it like that being careful and letting off when ever it would go past 30 but it was on and off like yours but then as i put more miles on like 6,000 it started spooling like a dog it wouldn't hit full boost for about 5 seconds So i checked shaft play for the hell of it and it spun free and decent shaft play not bad. but then i disconnected the wastegate from the o2 housing and it took all of my might to push in the rod. I just assumed the wastegat was bad but i didnt care because i replaced the whole unit with an fp black and when i went for the first drive i spooled it just a little bit to see if the problem went away and it did cause my fp black spooled faster then my 8 turbo so hope this helps...

jrohner

It could just be wastegate flutter.

Ian0611

iTrader: (41)

Thanks for the response! I do have some doubts about it being the wasgate because during the times that I have logged the problem with Evoscan, the wastegate appears to be following the Max Wastegate Duty Cycle table just the way that it's suppose too and it's not recording any fluttering. Is it possible that Evoscan wouldn't pick this up?

Ian0611

iTrader: (41)

Any other thoughts on this?

jrohner

WGDC is just the duty cycle of the solenoid, it's not logging the actual position of the wastegate actuator.

Ian0611

iTrader: (41)

Ahhhhh I see. Thanks for the clarification. So do you think it's more likely to be an issue with the wastegate actuator then and not the boost solenoid?

white8

iTrader: (14)

i just took my 02 housing off the turbo and the gasket was blown on the inside I think that may have been the problem

Ian0611

iTrader: (41)

I think I may have an exhaust leak around the downpipe or O2 housing so that could be it. The only thing is that I think that leak has been there for a while and I only started noticing this problem a few weeks ago.

Ian0611

iTrader: (41)

Bump for a few more opinnions on this. Thanks!

Ian0611

iTrader: (41)

Finally got a chance to look for that exhaust leak the other day and not only did I find one of the nuts about ready to fall off the O2 housing but part of the gasket is definitely blown out as well. Not real sure what do at this point. The cheapest thing to do would be to just replace the gasket but I'll pretty ticked if that doesn't fix the problem and if I'm going to go through all that work I'm tempted to just replace the whole turbo. I've been looking for a reason to upgrade anyway... LOL

white8

iTrader: (14)

Copper gasket spray works for me and a **** ton of others on here. it sounds scary to use a spray with no gasket but it works great. One guy on here has gone 15,000 miles no problem other guys dont use spray or gasket at all. 7 bucks for a can at any parts store

Ian0611

iTrader: (41)

Thanks for the suggestion. I was wondering if there was something like that out there so I may look into that and give it a shot. I actually am starting to think that the real problem is that my clutch is slipping , based on what I've read and seen from some others. Plus the problem is getting worse. When it first started happening I only noticed it 4th and 5th and now I notice it all gears.

drifterific

iTrader: (10)

Sorry to bump this up but I didn't want to start a new thread about this subject.

I just installed a MAC valve to use for boost control and am trying to get it all dialed in but at full boost 23-24 lbs the wastegate pulses (I have an EPM Open dump on the stock turbo) so I can really hear it pulsing. Any thoughts or ideas on why it is pulsing. When I was on the stock solenoid it would only pulse in 5th gear pulls and now it is in every gear.

Ian0611

iTrader: (41)

Sorry I didn't update this but my problem actually ended up being a slipping clutch. I didn't think that was the problem at first because it was so sporadic and always seemed to happen at the same place in the RPMs but the problem got a lot worse over the course of the last couple of weeks so I knew it had to more than just a boost table or something.