MY08 shaky power delivery

[spec.B]

Hey guys,

Having a bit of an issue with the lib with what I assume is a misfire. Completely stock running 98 RON. Two separate (but probably related issues)...

a) WOT pull in 2nd/3rd/4th from 2k - 4k rpm has some shaky patches in it. 4k to 6.5k seems smooth. 1st happens too quickly to tell.

b) For those in the Sydney area playing along at home, this happens pulling up the long hills on the F3. Under load in 5th/6th at highway speeds power delivery is subtle shaky. If I squeeze the throttle a little in 5th it will happily accelerate, it's not bogged down but it's not smooth. For reference it's about the same as sitting in the car stationary and having someone in the passenger seat shaking about.

I'm thinking it's probably plugs. Car has done 45k kms and they're original as far as I know. If i'm going to replace plugs, should I be getting one step colder, especially since I'm considering TBE + tune? Any brands/recommendations?

[bigBADbenny]

Start with the basics I reckon.
Clean MAF, check all hoses & inlet for leaks and the exhaust too.
Soapy water spray then aerosol in engine bay.
Log it and get a learning view.
Personally I wouldn't go the tune & upgrades without using a tactrix for logging and having some way to monitor vitals like boost & afr etc.

[Newbie GT]

Start with the basics I reckon.
Clean MAF, check all hoses & inlet for leaks and the exhaust too.
Soapy water spray then aerosol in engine bay.
Log it and get a learning view.
Personally I wouldn't go the tune & upgrades without using a tactrix for logging and having some way to monitor vitals like boost & afr etc.

So Benny you wouldn't trust a reputable tuner eg msr or the like unless you were consistently logging?

[bigBADbenny]

It's good to monitor the vitals for sure, regardless of tuner - and also to have some understanding of the various factors that contribute to the cars reliability.

[Newbie GT]

It's good to monitor the vitals for sure, regardless of tuner - and also to have some understanding of the various factors that contribute to the cars reliability.

But once tuned correctly isn't it set and forget besides regular maintenance ?

[bigBADbenny]

In a perfect world... Which its not.
Bad fuel, blown hoses, low oil, failing avcs, tunes without headroom...

[Newbie GT]

In a perfect world... Which its not.
Bad fuel, blown hoses, low oil, failing avcs, tunes without headroom...

I get the point lot of factors :/

[Newbie GT]

In a perfect world... Which its not.
Bad fuel, blown hoses, low oil, failing avcs, tunes without headroom...

However you would think the tuner would check all these out 1st

[seanmau5]

In a perfect world... Which its not.
Bad fuel, blown hoses, low oil, failing avcs, tunes without headroom...

However you would think the tuner would check all these out 1st

[peadya100]

Hey spec.b.
I had the same symptoms a while back and it ended up being a hose that had come off the blow off valve. Quick fix and worth a sticky beek if you haven't already looked at it

[bigBADbenny]

In a perfect world... Which its not.
Bad fuel, blown hoses, low oil, failing avcs, tunes without headroom...

However you would think the tuner would check all these out 1st

Not really unless you were paying them for that on top of your tune.
But all this is covered on the forum and of little relevance to the OP's call for assistance.

[Newbie GT]

In a perfect world... Which its not.
Bad fuel, blown hoses, low oil, failing avcs, tunes without headroom...

However you would think the tuner would check all these out 1st

Not really unless you were paying them for that on top of your tune.
But all this is covered on the forum and of little relevance to the OP's call for assistance.

Agree soz OP

[jp928]

I had something vaguely similar a while ago also - queried dealer, they said they found a hose cramped, crimped closed. It was a small (10-12mm OD) coming off the wastegate (I think). The problem came back again later, and I found it myself, and re-routed it , fixed oK. Check along the run of the big hose off the aircleaner to the turbo for a small hose next to, or underneath, being squashed.
jp 08 gtb 6mt

[spec.B]

Thanks peadya and jp; will check for any obvious hose issues before I go changing plugs.

benny; jumping straight to logging for a stock standard car seems a little over the top.

All: does anyone have a hose schedule or arrangement drawing/diagram, photos or anything for the common troublemakers? I've tried tracing stuff from the obvious blow off valve/wastegate/turbo areas before but they disappear into the bowels of the engine pretty quickly.

[bigBADbenny]

benny; jumping straight to logging for a stock standard car seems a little over the top.

Not really at all, since stock cars expire all the time due to wear and tear and the factory tune etc.
Plus you want to be ready for keeping an eye on things after your impending upgrades.
Its also just great for your independence, mechanical sympathy and understanding of your car - especially if you're considering mods.

All: does anyone have a hose schedule or arrangement drawing/diagram, photos or anything for the common troublemakers? I've tried tracing stuff from the obvious blow off valve/wastegate/turbo areas before but they disappear into the bowels of the engine pretty quickly.

Yes its under General Description / Inlet Manifold in your WSM. I can PM you the pages for an MY07 if you need.