OK, this is bugging me... any suggestions please guys?
1999 S40 T4, hasn't been boosting right for a while. Trying to get it back to 1.0bar stock boost.
Originally was boosting to just 0.4bar, suspected the boost control solenoid so replaced with a Blitz dual-spec R boost controller (good for 2+bar) that I had lying around. Now we get 0.7bar but no more, even with the Blitz wound right up to 100% (a bit scary trying THAT!)
The car spools up nicely to 0.7bar but then will just hold 0.7 and dump the excess boost to atmosphere. Quite an abrupt effect, I could believe that the Blitz was cutting in early but can't see any evidence for this.
Checked for the usual air leaks etc, nothing found. Wastegate actuator feels reasonably tight, not sloppy.
Currently has an atmospheric DV AND the standard recirc, which might be causing the issue? I'm blanking off the recirc valve later this week to see if that might help...
What else can we think of?
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Monday 11th August 2008, 12:52 #1Senior Member
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Thanked 887 Times in 593 PostsT4 won't boost past 0.7bar... help please!
Alastair
Current: 2009 Cayenne GTS and a 2016 Prius IV... yes.
Previous Volvos: 2009 V50 D5 R-Design, 2005 V70R, 2001 V70 T5, 2001 S40 T4, 2x 1999 S40 T4, 2003 V40 T4, 1999 V70 T5, 1996 854 T5 & 855 T5, 1995 855 T5, and a 480...
Previous other stuff: Saxo Turbo, 2004 996 C4S, 2008 Z4M, 2001 Yaris T-Sport, 2002 S2000 Mugen, and a 1999 Evo VI
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Monday 11th August 2008, 15:02 #2Senior Member
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Thanked 103 Times in 97 Postswhat is the recuirc valve connected too? if nothing then thats most probably your problem as they require boost pressure to hold them shut....
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Monday 11th August 2008, 15:09 #3Senior Member
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Thanked 887 Times in 593 PostsIt's connected to the intake manifold...
Alastair
Current: 2009 Cayenne GTS and a 2016 Prius IV... yes.
Previous Volvos: 2009 V50 D5 R-Design, 2005 V70R, 2001 V70 T5, 2001 S40 T4, 2x 1999 S40 T4, 2003 V40 T4, 1999 V70 T5, 1996 854 T5 & 855 T5, 1995 855 T5, and a 480...
Previous other stuff: Saxo Turbo, 2004 996 C4S, 2008 Z4M, 2001 Yaris T-Sport, 2002 S2000 Mugen, and a 1999 Evo VI
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Monday 11th August 2008, 16:31 #4Senior Member
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Thanked 2 Times in 2 PostsWhat does your vac read at when the car is idle?
1998 S40 T4Two Hundred Horses of Swedish Boost Action!!
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Monday 11th August 2008, 16:37 #5Senior Member
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Thanked 342 Times in 293 PostsCould there be a blockage in the exhaust system? I remember someone on this site having a problem with a blocked cat tha resulted in no more than 0.8 bar of boost and it worked fine up until that figure.
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Monday 11th August 2008, 17:19 #6Senior Member
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Thanked 887 Times in 593 Posts0.7ish from memory, but I don't recall the units
Originally Posted by Stevie-Boy
What could I tell from this?Alastair
Current: 2009 Cayenne GTS and a 2016 Prius IV... yes.
Previous Volvos: 2009 V50 D5 R-Design, 2005 V70R, 2001 V70 T5, 2001 S40 T4, 2x 1999 S40 T4, 2003 V40 T4, 1999 V70 T5, 1996 854 T5 & 855 T5, 1995 855 T5, and a 480...
Previous other stuff: Saxo Turbo, 2004 996 C4S, 2008 Z4M, 2001 Yaris T-Sport, 2002 S2000 Mugen, and a 1999 Evo VI
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Monday 11th August 2008, 17:20 #7Senior Member
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Thanked 887 Times in 593 Postshehee, my first T5 came with a collapsed cat and that prevented ANY boost! Great fun once we'd sorted THAT! Originally Posted by Alan M
I think the exhaust should be fine as it's only a year old (through from the turbo back).
Thanks though!Alastair
Current: 2009 Cayenne GTS and a 2016 Prius IV... yes.
Previous Volvos: 2009 V50 D5 R-Design, 2005 V70R, 2001 V70 T5, 2001 S40 T4, 2x 1999 S40 T4, 2003 V40 T4, 1999 V70 T5, 1996 854 T5 & 855 T5, 1995 855 T5, and a 480...
Previous other stuff: Saxo Turbo, 2004 996 C4S, 2008 Z4M, 2001 Yaris T-Sport, 2002 S2000 Mugen, and a 1999 Evo VI
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Monday 11th August 2008, 17:31 #8Senior Member
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Thanked 64 Times in 60 PostsRecirc valve is the most probable cause imo. blanking plate required.
"I am never wrong! Just in a position to learn something new!"
Mods so far, HLM ReMap, Goodridge brake lines, Eibach springs lowering 35mm, K&N57i filter with cold air, Strut brace, Shark fin aerial, Boost guageYES IT'S A DIESELWish list, BOV, 18" rims, Struts, Stainless exhaust, Injector Upgrade, MORE POWER!
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Monday 11th August 2008, 20:17 #9Senior Member
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Thanked 887 Times in 593 PostsWeird if the stock recirc can handle a bar of boost... unless it's having issues working in tandem with the atmospheric dv? Quite possible I suppose... Originally Posted by CONDYBOY
Alastair
Current: 2009 Cayenne GTS and a 2016 Prius IV... yes.
Previous Volvos: 2009 V50 D5 R-Design, 2005 V70R, 2001 V70 T5, 2001 S40 T4, 2x 1999 S40 T4, 2003 V40 T4, 1999 V70 T5, 1996 854 T5 & 855 T5, 1995 855 T5, and a 480...
Previous other stuff: Saxo Turbo, 2004 996 C4S, 2008 Z4M, 2001 Yaris T-Sport, 2002 S2000 Mugen, and a 1999 Evo VI
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Monday 11th August 2008, 21:53 #10Senior Member
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Thanked 2 Times in 2 PostsSo your vac is at 10psi when the car is idling then. That sounds alright really, a dodgy vac value could point to a boost leak.
Just thinking, if you're boosting to 10psi and the standard boost is 13psi(?) then it's probably going to end up being something like a minor boost leak or that recirc as it's not a massive drop in boost. Be interesting to see what does happen when you blank that off.Last edited by Stevie-Boy; Monday 11th August 2008 at 22:11.
1998 S40 T4Two Hundred Horses of Swedish Boost Action!!
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The Following User Says Thank You to Stevie-Boy For This Useful Post:
Al115 (Tuesday 12th August 2008)
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Tuesday 12th August 2008, 01:43 #11Senior Member
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Thanked 23 Times in 15 Postshave you tried running a straight vac hose from the inlet to the actuator?
this will at least let you know at which point the actuator pops open and bleeds off
RossAll fast cars long gone. Sensible family BMW 3 series now.
Still Volvo links though as my wife has a V50 R design sport and a mildly fettled
T4
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Tuesday 12th August 2008, 09:07 #12Senior Member
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Thanked 887 Times in 593 PostsNo I haven't and maybe I should! Good idea thanks. Can try it tonight... Originally Posted by Ross9
Any risks involved in doing this that I should be aware of?
Alastair
Current: 2009 Cayenne GTS and a 2016 Prius IV... yes.
Previous Volvos: 2009 V50 D5 R-Design, 2005 V70R, 2001 V70 T5, 2001 S40 T4, 2x 1999 S40 T4, 2003 V40 T4, 1999 V70 T5, 1996 854 T5 & 855 T5, 1995 855 T5, and a 480...
Previous other stuff: Saxo Turbo, 2004 996 C4S, 2008 Z4M, 2001 Yaris T-Sport, 2002 S2000 Mugen, and a 1999 Evo VI
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Tuesday 12th August 2008, 10:10 #13Senior Member
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Thanked 103 Times in 97 Postshave you checked for any hidden codes?
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Tuesday 12th August 2008, 10:31 #14Senior Member
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Thanked 887 Times in 593 PostsGood point and no I haven't, will have a crack at that too.
Alastair
Current: 2009 Cayenne GTS and a 2016 Prius IV... yes.
Previous Volvos: 2009 V50 D5 R-Design, 2005 V70R, 2001 V70 T5, 2001 S40 T4, 2x 1999 S40 T4, 2003 V40 T4, 1999 V70 T5, 1996 854 T5 & 855 T5, 1995 855 T5, and a 480...
Previous other stuff: Saxo Turbo, 2004 996 C4S, 2008 Z4M, 2001 Yaris T-Sport, 2002 S2000 Mugen, and a 1999 Evo VI
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Wednesday 20th August 2008, 18:40 #15Senior Member
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Thanked 887 Times in 593 PostsUpdate... not too positive...
No DTCs stored.
Blanked the recirc valve off and retested... no change whatsoever (apart from more noise...)
It feels to me like something is dumping boost at 0.7bar, but I can't blame the Blitz as the same thing was happening when the stock BCS was fitted!
Guess it might be time to hunt for holes in hoses, but I've been through that once... any pointers? Suggestions? Words of encouragement?
Cheers guys...Alastair
Current: 2009 Cayenne GTS and a 2016 Prius IV... yes.
Previous Volvos: 2009 V50 D5 R-Design, 2005 V70R, 2001 V70 T5, 2001 S40 T4, 2x 1999 S40 T4, 2003 V40 T4, 1999 V70 T5, 1996 854 T5 & 855 T5, 1995 855 T5, and a 480...
Previous other stuff: Saxo Turbo, 2004 996 C4S, 2008 Z4M, 2001 Yaris T-Sport, 2002 S2000 Mugen, and a 1999 Evo VI
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Wednesday 20th August 2008, 18:48 #16Senior Member
CDO Sufferer
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Wastegate actuator diaphragm split?
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Wednesday 20th August 2008, 20:27 #17Senior Member
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Thanked 103 Times in 97 Poststhat would stop the wastegate opening.... i would expect more boost than 0.7bar even with the leak via the diaphragm Originally Posted by jimka
She may not be perfect but i love her anyway....
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