need help

2002 wrx 80+miles no mods, except up-pipe and hks blow off valve.

i seem to have a problem, whenever turbo kicks in after 3k rpm it seems to surge not boost but surge, and theres lack of power there also. would i need to get a new turbo, i don't think its leaking any where.

 

When did you have your BOV installed, is it a circulating BOV or a atmosphere? And can you describe the surge, is the car going slow when this happens?

 

I would check to see if you have boost leak. I have seen the y pipe on the under side of the intercooler crack.

 

i had my bov install about 2yrs ago, and its a atomosphere bov, and the car does not slow down, but when the car boost theres no power, the rpm would surge, drop back down and then the car would pick up.?

 

have not done that one yet.

 

Hard to tell as I'm trying to picture this, but almost sounds like a clutch to me, surge as in the engine rev's up and the car doesn't accelerate? Have you checked to see if the BOV is stuck open, thats happened to me before as well. If it is stuck us something to lubricate it.

 

no no no, the car is in gear and moving already, but would happen when i accelarate.
i'll have to check the bov thing also, i might need a new clutch also but im pretty sure this is not the culprit.

 

Ummm what?

So your moving in gear, and you floor the car, and then the RPM's jump up, but the car doesn't move any faster?

YOU NEED A CLUTCH!!

 

This sounds similar to my situation: the boost surges so it feels like a pause to catch it's breath or something for a half a second or so. I have plenty of acceleration, it just surges rather than being smooth. The surge happens probably about 3-4 times if I am really accelerating in say, third gear. The other gears do it, too; but most of my quicker or longer acceleration is in third (by driving style).

What has been suggested to me: Silicone Y-Pipe to replace the stocker. Replace the Boost Control Solinoid.

My car is a completely stock 02 WRX Wagon except for EBC Rotors and Green Stuff pads.

Dunno if that info will help, but this thread is of interest to me, too.

 

Does the turbo seem to be 'hunting' for boost by going up and down while normally it would be a solid pressure? If so... could be a cracked vac line or a vac line that leaking at it's mounting point.

If the boost is surging like this, there may be an issue in the wastegate system. Our cars run a pressure bleed type of wastegate. This means there is a direct positive boost line that connects the turbo to the wastegate, then there is a T in the line that is routed to the boost control solenoid (we'll call it BCS). The BCS vents some of the boost pressure going to the wastegate acutator, and by this controls the amount the wastegate is opened. The BCS is controlled by the ECU from readings from the boost pressure sensor (we'll call him the BPS). If there is a leak somewhere in the vac/boost line system the boost will be leaked prior to the BPS the ECU will think the car is running under no boost, and close the wastegate all together. This causes a spike in boost pressure. As the pressure increases the air normally leaked is now too great to vent through the hole, and reaches the BPS. BPS tells the ECU there is too much boost now, the ECU tells the BCS to open the wastegate and drop the boost level. Then the cycle starts over again.

Vac lines on turbo cars are prone to premature wearing. This is caused by the constant stretching (boost) and contraction (vac) that our vac lines endure. Add to this the cold temps that you are seeing and it's tendency to harden/freeze the lines, which causes cracks and poor sealing properties.

I was having the same issue on my wife's car while I was in town, along with a boost leak under acceleration. The surging was caused by the small vac line between the turbo and the T leading to the wastegate actuator and the BCS. The boost leak was caused by the vac line feeding the BPV allowing boost pressure to leak where the hose met the BPV's nipple. New lines, and clamps, and no issues anymore.

 

my rpms would only jump up to about 4k and back down to 3k and then boost.
it's kind off hard to explain.but no it's not jump around like what you re thinking about.

 

First... get rid of the BOV.
Second check for any leaks
And then go from there. Dont just buy a new turbo when the prob could be something little. i speak from experience, BOV made my car run like complete a$$.

 

all great info guys, i will proceed to hunt this thing down just haven't had anytime to really look at it yet. thank you guys.

 

i had the bov on for a few yrs without any probs, when i had a cat-back and stage 1 accessport, but when i took everything off except the up-pipe and bov, i did notice that my bov got quietier and quietier, and now i have to really step on it to hear it.?

 

will try it out.

 

Any updates?

 

i'm thinking that it may now be my clutch, how would you know for sure?

 

If its a clutch you'll notice it more during cold starts. Its important that you replace it before it fails completely otherwise you'll be stuck and unable to drive the car. Try accelerating from 1st thru 3rd gear, not too crazy agressive but enough to tell if its slipping.

 

Could most likely be your bov. Hks bovs are notorious to cause all kinds of problems. Had one went and had surging problems with mine.

 

lmao @ nobody else listening to him.

It's the clutch. /thread

 

LMAO. Obviously the clutch is slipping.
He did say it jumps to 4k then goes back to 3k and starts boosting.