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Discussion Starter · #1 ·


in the picture above, my main hose that runs from the nipple in the valve cover to the intake to the turbo broke (just before where the hose leaving the tb connects), so i finally installed my catchcan.

but my question is, the circled hose/port on the tb runs into the main hose also. what is the purpose of this?

my understanding is that under boost, this hose plays the role of sucking oil vapors out of the valvecover, and into the intake pre turbo, so they are then reburned. but why would you want to suck air out of the TB?

my only thought is that it provides the vacuum pull to remove vapors when the turbo is not providing boost.

if this is the case, would it make sense to run a line from that port to the catchcan so that it also has some pull to help extract the vapors?
 

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Saab Mad
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That hose takes coolant from the throttle body all around the blow-by hose. There's no gases in it, just coolant. It doesn't run INTO the main hose, it runs AROUND it.

You ask: what's the point? my guess is that it keeps the pipe warm preventing blow-by to condensate and oil drops hitting the compressor blades.
 

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Discussion Starter · #3 ·
yeah if its coolant that makes sense.

it does go into the big hose tho, i guess it next to another smaller hose within?
 

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If you check the main pipe, you'll see that it has an outer sleeve where the coolant flows. Blow-by gases in, coolant out. You'll also see a small metal pipe on the other end of the main pipe, close to the turbo. That's where the coolant that goes in from the pipe you indicated comes out (or it's the other way around? whatever).
 

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Mind these cars were built by the trolls in the land of snow balls

The water heater pipe is to stop oil emulsion sludge plugging off in the vent pipe. Likewise the throttle body water supply pipes stop the throttle butterfly from icing up & in the later models the inlet heater plate helps with combustion efficiency. All three items can be removed if your climate allows
 

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Norman Lovie said:
The water heater pipe is to stop oil emulsion sludge plugging off in the vent pipe. Likewise the throttle body water supply pipes stop the throttle butterfly from icing up & in the later models the inlet heater plate helps with combustion efficiency. All three items can be removed if your climate allows
Makes sense. Thanks.
How warm should the climate be to allow these devices to be removed? did you do it in your car? could I do it, considering that where I live I might get the odd -5°C week then spend the whole winter around freezing point?
 

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I,ve done the heater plate & the throttle body hot water pipes. haven,t done the vent but will in due course.

Were presently getting up to -10degc = I refit the throttle pipes in the winter, basically i,ve got a piece of pipe and I join the two hoses together to bypass, seems a bit daft to heat up the throttle after the IC is trying its best to cool it down, but at regular - degC conditions, any benifit is lost & it will prevent the throttle from icing up and sticking ( although i,ve never experienced this)
 

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I disconnected all the above items and didn't experience any problems except now the intercooler and pipework remained nice and clean instead of being coated in oil.
 

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Marrk said:
I disconnected all the above items and didn't experience any problems except now the intercooler and pipework remained nice and clean instead of being coated in oil.
And this is probably the most efficient reason for doing it, the IC with a coating of oil is a bloomin good thermal insulator:roll:
 

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No, what is the reason for the oil tube to go in front of the turbo? Could it be for some lubrication reason or something? I mean why would engeneers go through all the troubles of installing it if there is no point? Especially because there is another "PCV" hose going on top of the intake manifold...

Klim
 

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mulik51 said:
No, what is the reason for the oil tube to go in front of the turbo? Could it be for some lubrication reason or something? I mean why would engeneers go through all the troubles of installing it if there is no point? Especially because there is another "PCV" hose going on top of the intake manifold...

Klim
One works when you're on boost, one when you're off boost. You don't want to pressurize the crankcase with boost, right?;)

marrk said:
... now the intercooler and pipework remained nice and clean instead of being coated in oil.
Don't understand why :confused:
Are you talking about the inside or the outside?
My intake pipe is quite clean on both the outside and outside. Havent's checked the inside of the IC though...
 

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Over time the oil misting coat,s the inside of the IC, doesn,t take a lot, but next time you,ve got it off give it a wash out with acetone or petrol etc.., best leave to soak.

A good indicator is the std saab hose bends from the turbo to IC, run your finger inside them to see how much "tar" is there
 

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Norman Lovie said:
Over time the oil misting coat,s the inside of the IC, doesn,t take a lot, but next time you,ve got it off give it a wash out with acetone or petrol etc.., best leave to soak.

A good indicator is the std saab hose bends from the turbo to IC, run your finger inside them to see how much "tar" is there
Oh I understand now, I thought Marrk was talking about removing only the blow-by pipe heating (and I couldn't understand how it could help with gunk in the intake), but actually he did remove all the blow-by system and fitted a mere air filter in place of the whole system... I remember his post about this now.
 
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