Slow to build boost, and boost is low
Discussion
I have a Volvo with the 2.3 litre inline five engine, specifically the high pressure turbo version.
It should boost to ~1.4 bar, and it should do so rapidly - but it currently boosts lazily and only to around 0.8 bar.
I have tried a number of things, up to disconnecting the line from the boost control solenoid to the wastage actuator - and it still would not boost beyond 0.8 bar.
Inspecting the turbo the shaft spins freely, with no discernible play.
What is the failure mode at work here (I'm pretty certain it's the turbo), and how is it likely to play out, ultimately - bits of turbine in the intercooler?
Also - if I get it rebuilt by Turbo Dynamics, is it worth replacing the journal bearings with ball bearings (TD04 19T)?
It should boost to ~1.4 bar, and it should do so rapidly - but it currently boosts lazily and only to around 0.8 bar.
I have tried a number of things, up to disconnecting the line from the boost control solenoid to the wastage actuator - and it still would not boost beyond 0.8 bar.
Inspecting the turbo the shaft spins freely, with no discernible play.
What is the failure mode at work here (I'm pretty certain it's the turbo), and how is it likely to play out, ultimately - bits of turbine in the intercooler?
Also - if I get it rebuilt by Turbo Dynamics, is it worth replacing the journal bearings with ball bearings (TD04 19T)?
Dammit said:
I have a Volvo with the 2.3 litre inline five engine, specifically the high pressure turbo version.
It should boost to ~1.4 bar, and it should do so rapidly - but it currently boosts lazily and only to around 0.8 bar.
I have tried a number of things, up to disconnecting the line from the boost control solenoid to the wastage actuator - and it still would not boost beyond 0.8 bar.
Inspecting the turbo the shaft spins freely, with no discernible play.
What is the failure mode at work here (I'm pretty certain it's the turbo), and how is it likely to play out, ultimately - bits of turbine in the intercooler?
Also - if I get it rebuilt by Turbo Dynamics, is it worth replacing the journal bearings with ball bearings (TD04 19T)?
Maybe a air leak or the cat/exhaust partially blocked??It should boost to ~1.4 bar, and it should do so rapidly - but it currently boosts lazily and only to around 0.8 bar.
I have tried a number of things, up to disconnecting the line from the boost control solenoid to the wastage actuator - and it still would not boost beyond 0.8 bar.
Inspecting the turbo the shaft spins freely, with no discernible play.
What is the failure mode at work here (I'm pretty certain it's the turbo), and how is it likely to play out, ultimately - bits of turbine in the intercooler?
Also - if I get it rebuilt by Turbo Dynamics, is it worth replacing the journal bearings with ball bearings (TD04 19T)?
Dammit said:
Checked the cat with a bore scope after dropping the down pipe- clean as a whistle, and you can see through it (100 cell race cat)
What is your thinking ref air leak?
Well if you're tyre leaks air....it will have less pressure in it. If there is a leak anywhere within the turbo system...it will have to work harder to maintain any pressure...if it is even capable.What is your thinking ref air leak?
Really there could be many causes, and generally a visual and manual inspection on the turbo is usually a fairly reliable one so should rule that out.
It could be a leaky pipe, blown intercooler, blocked exhaust. If you've removed the wastegate actuator pipes and it's still not making much boost, that would generally rule out an engine control problem and again point to an air leak or blockage.
Dammit said:
Checked the whole of the charge pipe work - found the (inevitable) small boost leak, but it is small- not nearly enough to account for the amount of boost that is missing.
Both silencers are straight through types- could they possibly be blocked?
Depends on their internal design. Anything is possible...shove something up and see, if you are unable to actually see.Both silencers are straight through types- could they possibly be blocked?
Is the wastegate flap actually working ? not jammed open or anything ? undo the rod and see what the flap feels like
Inspected the wastegate when the downpipe was off- moves and seals fine.
This is one of those cases where we can find nothing wrong, but something clearly is.
We tested the actuator also, and that was fine.
It's as though the turbo can't spin beyond a certain speed, yet spins freely when you inspect it.
I'm pretty much at the point where I'll send the turbine to turbo dynamics just to rule that out as the problem.
This is one of those cases where we can find nothing wrong, but something clearly is.
We tested the actuator also, and that was fine.
It's as though the turbo can't spin beyond a certain speed, yet spins freely when you inspect it.
I'm pretty much at the point where I'll send the turbine to turbo dynamics just to rule that out as the problem.
stock recirc diaphrams struggle running over a bar in good condition , I have just had my 15g done by turbo dynamics with 19t upgrade and they had new diagphrams if you need one as they are a bit steep if you go off the Mitsubishi part no . Lambda light is a bit misleading as its really the check engine light and the early motronic doesn't have a lot of codes to read and certainly nothing about cat efficiency as there isn't a post cat lambda if it's an early car
There is no post cat lambda in mine- I'm not that concerned about the light to be honest, I suspect the Lambda sensor didn't like being removed when we dropped the downpipe.
Be handy if Volvo had not used their own OBD version for these cars, but as they did no garage ever seems able to read the codes.
Be handy if Volvo had not used their own OBD version for these cars, but as they did no garage ever seems able to read the codes.
Dammit said:
Mine is an 850R - a version of the 850 T5.
The fastest way to move a wardrobe, in 1996.
They're transverse mounted ? not inline.The fastest way to move a wardrobe, in 1996.
Is there no way to flash fault codes from the ecu ?
http://www.volvoforums.org.uk/showthread.php?t=838...
It may not tell you the problem, but if the light is on, it may help a little. But it may well be the turbo too, in which case no amount of fault codes will tell you that
Edited by stevieturbo on Saturday 27th December 22:19
We took the boost control solenoid out of the circuit (first with an MBC, then just an open line to the actuator) and the turbo boosted to 0.8 bar and no more.
We also screwed the actuator shut and the same symptoms were observed.
What we have not done is investigate the (forgotten the correct term) air recirc valve.
Could it be acting as a massive boost leak?
We also screwed the actuator shut and the same symptoms were observed.
What we have not done is investigate the (forgotten the correct term) air recirc valve.
Could it be acting as a massive boost leak?
Dammit said:
We took the boost control solenoid out of the circuit (first with an MBC, then just an open line to the actuator) and the turbo boosted to 0.8 bar and no more.
We also screwed the actuator shut and the same symptoms were observed.
What we have not done is investigate the (forgotten the correct term) air recirc valve.
Could it be acting as a massive boost leak?
Mighty Kitten did suggest this over a week ago. Yes it is possible.We also screwed the actuator shut and the same symptoms were observed.
What we have not done is investigate the (forgotten the correct term) air recirc valve.
Could it be acting as a massive boost leak?
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