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Discussion Starter · #1 ·
My 9k developed a coolant leak recently, which took me a while to track down. I eventually traced it to the point where the crankcase breather connects to the air intake (just before the turbo).

Right next to it, there is a small rubber pipe apparently going into the intake. The other end connects to a thin metal pipe which went off around the block somewhere.

Anyone know what on earth this is for? Some primative form of water injection maybe? It's the last place I was expecting to find coolant! Or is it a vacuum pipe and something else is leaking into the pipe?

Regards,
Alan
 

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Well, when I followed the water circuit on my 9-5 the small metal tube comes from the turbo. Presumably the water in the tube is heated as it goes through the turbo and so provides warmth to the throttle body.

There's a flow diagram I worked out here for the 9-5.
 

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This is, as you say, part of the positive crank ventilation system. Basically, there is a pipe going from the crank breather to the inlet, before the turbo.

The complication is that this pipe has a water jacket running around it for part of the way. I think this is to stop the emissions condensing on the wall of the pipe?

Anyway, that's what it is. The pipe is double skinned, coolant on the outside. The water should not enter the intake system, they should be kept separate!
 

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Discussion Starter · #6 ·
Originally posted by sgould:
[qb]Well, when I followed the water circuit on my 9-5 the small metal tube comes from the turbo.  [/qb][/b]
Yes, I've got one of those too, but this is an additional metal pipe, connected (apparently) to the thick air intake just before the turbo.

Originally posted by JohnCC:
[qb]The complication is that this pipe has a water jacket running around it for part of the way. I think this is to stop the emissions condensing on the wall of the pipe?

Anyway, that's what it is. The pipe is double skinned, coolant on the outside.
[/qb][/b]
Ah, that's interesting, I hadn't noticed that. I'm going to try replacing the leaky hose tonight, so I'll have a closer look and report back. Might even take a few photos if it's bright enough.

Thanks for the replies guys,

Alan
 

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Discussion Starter · #7 ·
Well, I just changed the hose this evening, and now it all makes sense.

You were both quite correct, it is a throttle body heater, and it takes an 'interesting' route to the throttle body.

The metal pipe is connected to the turbo coolant pipe via a 'T' piece. It then connects to a short rubber pipe (the leaky bit), then connects to another metal pipe that runs up inside the crankcase breather hose (presumably to keep it warm), then connects to the throttle body via a rubber hose. Bizarre, but sort of logical in a Saab sort of way.

The change from metal pipe to rubber hose had confused me - I had originally thought that it was a vacuum hose going into the throttle body.

BTW, the old rubber hose had started breaking up, and just fell apart in my hands when I took it off. I replaced it with some reinforced fuel line pipe which should last a lot better.

Cheers,
Alan
 
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