New boost problems

2.7 V6 30v biturbo - 251bhp
2.7 V6 30v biturbo - 261bhp
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JUT
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New boost problems

Post by JUT » Mon Sep 24, 2007 10:12 am

Bloody cars! Only got my car out of limp mode less than 100 miles ago, and it's back in it again!

Previously it appeared that some shonky reassembly by a local garage led to one of the solid plastic intercooler pipes blowing off under pressure, which through some convoluted process seems to have blown a diverter valve... Valve replaced, car out of limp mode, away I go...

Yesterday, was driving along, giving it a bit of a boot, and a major hissing noise developed under boost - hissing louder the harder you accelerate - but yet the car drove fine (i.e. didn't conk out at idle like it had when the hose blew off last month)

I did a cursory check of the hoses that are visible from the top of the engine, and I couldn't see anything amiss, but the car has gone into limp mode again so barely generates enough boost for the hiss to be audible. I'm thinking it sounds like a split hose, but I'm not sure where to still allow the car to idle fine. Any ideas? Like I say, the car still starts and idles ok, no blue smoke or anything like that, just a loss of boost and the accompanying hissing.

JUT
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RE: New boost problems

Post by JUT » Mon Sep 24, 2007 10:27 am

Incidentally, as a side question, I've noticed that several of the hoses in the engine bay are not in great condition, as you'd probably expect on a 9 year old car with 92k on the clock - I'm thinking of replacing all the boost hoses with a silicone set. I have found a supplier on ebay who will do a set for just under £100 delivered:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :IT&ih=012

But I'm not sure if this is a false economy and whether I should just bite the bullet and shell out £250 for a Samco set:

http://cgi.ebay.co.uk/SAMCO-SILICONE-TU ... dZViewItem

Is there likely to be a lot of difference in the quality of the hoses? I have asked the seller of the cheaper set who they are manufactured by and how many ply the hoses are, but depending on whether they know their product I may not get an answer...

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ChipHazzard
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RE: New boost problems

Post by ChipHazzard » Mon Sep 24, 2007 10:32 am

JUT

where about's are you as you might have someone nearby that can do a pressure test for you. It sounds like a boost leak to me have you check for codes with vag-com yet ?

Cheers

Mike
FL Noggy S4 Avant

710N's, afterrun mod, MRC Generic Map & RS246 sticker
Kwack ZX7R & DRZ400 supermoto

JUT
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RE: New boost problems

Post by JUT » Mon Sep 24, 2007 10:38 am

I'm in North London, not sure of anywhere that does boost pressure checks near me, except maybe SCC Performance in St Albans. I don't have a vag-com, really should stop being tight as both me, my brother and my mum all drive vag-group cars and I'm sure it would come in handy!

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ChipHazzard
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RE: New boost problems

Post by ChipHazzard » Mon Sep 24, 2007 10:46 am

I'm sure there's someone in your neck of the woods that's got vag-com ad a pressure tester on here. failing that i'm not too far away in dartford
FL Noggy S4 Avant

710N's, afterrun mod, MRC Generic Map & RS246 sticker
Kwack ZX7R & DRZ400 supermoto

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dodgydave
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Re: RE: New boost problems

Post by dodgydave » Mon Sep 24, 2007 11:01 am

JUT wrote:I'm in North London, not sure of anywhere that does boost pressure checks near me, except maybe SCC Performance in St Albans. I don't have a vag-com, really should stop being tight as both me, my brother and my mum all drive vag-group cars and I'm sure it would come in handy!
Jut,

I can do a health check and preassure test your motor. Give me a ring 07769704322

I'm E17 Walthamstow.

Dave
Never enough...

JUT
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RE: Re: RE: New boost problems

Post by JUT » Mon Sep 24, 2007 11:08 am

Sweet, cheers

bobbler
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RE: Re: RE: New boost problems

Post by bobbler » Mon Sep 24, 2007 11:44 am

JUT, I just got those very same £100 hoses in front of me this morning. They seem to be no different in feel and build than Samco sets that I have had before.
Only thing I would say is that they could do with a good clean before installation as there seems to be a lot of dust inside them. I can live with that personally.
I will be fitting them later on so will let you know if they are made to the correct sizes too.
. S4 Nogaro Blue Avant . ECS IV . RS4 handling bits . 18" Ultraleggera . AWE Boost Gauge . MRC Custom Map . 315 BHP . 482 Nm .

JUT
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RE: Re: RE: New boost problems

Post by JUT » Mon Sep 24, 2007 11:55 am

Excellent, would be good to hear if they are worth a punt

JUT
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RE: Re: RE: New boost problems

Post by JUT » Mon Sep 24, 2007 1:58 pm

Just to add a little about those cheaper hoses, the seller confirmed that all those hoses are 3 ply and that the set is 12 hoses not 14 as stated in the listing on ebay. I believe Samco use 3 ply up to 76mm and then 4 ply thereafter, so if an of the hoses are bigger than 76mm on the S4, the Samco set may be up to more punishment. If not, the cheaper set looks like a bit of a bargain.

bobbler
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RE: Re: RE: New boost problems

Post by bobbler » Mon Sep 24, 2007 3:51 pm

Well, it fitted. Ended up just replacing the TBB this morning as I didn't have a load of spare replacement clips/jubilees to do the rest.
Fit is nice and snug, has same issue as with the Samco set, that of the sensor mounting point being too high up to get the engine cover back on. I trimmed it down as much as I felt happy doing but still wouldn't create enough clearance.
All in all I am very happy with it at the moment as it has fixed this and I am back to 15ish PSI of boost again.
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. S4 Nogaro Blue Avant . ECS IV . RS4 handling bits . 18" Ultraleggera . AWE Boost Gauge . MRC Custom Map . 315 BHP . 482 Nm .

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