these symptoms equal?

[turkey]

Here's what my bh5 tt is doing.when the water temp is cold it has bad hesitation under any acceleration, but the moment the temp is normal problem hardly noticeable.If i turn off car for a couple of minutes and then drive again problem is back for up to 30 seconds.What could be causing this?Temp sensor?oxy sensor?

Also while driving at any speed, any gear, if i gently accelerate, once i reach about 3 inhg the boost will increase to about 2-3 psi even though there's been no change in acceleration or load on the engine. decelerating, when i reach 1inhg then it drops to 3or 4 inhg.this makes it near impossible to keep a constant speed on the open road

Any help out there?

[Guest]

I cant give you the answers as to why, but I can say that it is exactly the same manner that my bh5 performs. I've had it checked by several different garages and have been told 'its nothing to worry about', so I'm going to believe them.

I would probably say though, that the electronics controlling the spooling of turbos, fuel feed, air ratio etc must be complicated having two turbos..so its likely that there would be some weirdness at some point.

[turkey]

was anything replaced at all when you had it looked at? I can't help but think its something mechanical though.

[Guest]

Nothing that I'm aware of has been replaced. The only thing I can say is that once the engine is up to running temp its fine. Makes me think it could be metal contraction/expansion causing more friction?

[Guest]

I believe that a bunch of sensors are ignored at startup for a short period which may explain why it is a little odd when warm just after startup.

As for when cold... there is a bunch of things going on when cold like no O2 sensor data and the ECU knowing the car is cold so they all do that.

The small amount of boost you are seeing is normal... what will be happening is that at that engine speed and throttle opening the primary turbo is finally starting to spin fast enough to produce measurable boost. Before 3k rpm at that throttle opening there probably isn't enough exhaust gas flow to spin the turbo fast enough to produce boost.

[ReubenH]

 Heroes Legend said:

I would probably say though, that the electronics controlling the spooling of turbos, fuel feed, air ratio etc must be complicated having two turbos..

Yes and no. Generally your average mechanic won't want to touch the TT, the operation of them is a nightmare.

BUT, sensors and computer are all the same as the simple ol single turbo's. The difference is there's simply additional solenoids.

Have either of you checked the check engine light codes? Trust me, there could easily be a code in there, despite it never showing the CEL. I had an o2 sensor unplugged for 2 weeks before the car finally decided to show the CEL.

[Guest]

Yea, given my previous threads about the fuck-up from the last 'service' at auckland subaru specialists, its been to 3 different garages since. Have raised this informally and nothing untoward has come back. Right now, my car is as squeeky clean as wingers can make it, and its still present so am happy to just live with it. Besides, I shouldnt be raping the engine when its cold, and neither should you!

[D-Style]

Sounds like a Temp sensor.

Thou my B4 wasnt the best when cold.

[turkey]

My wagon has no codes, and with the issue of boost it does it at any rpm, any gear, under any condition.i've never noticed this on a previous tt (bg5) i had or single turbo cars i've had as well.Anyone know what sort of price for a new temp sensor is?

[D-Style]

around $65 when i got it. Got to buy from Subaru thou.

[Guest]

it sounds like an afm. it gets corrected when in closed loop. swap one over from any other turbo car with that style AFM to check, disconnect the battery before testing as the fuel trims will be up the shit.