UKSaabs

I've just seen a mention of an EVAP valve "bolt mod" for T7 engines. Can someone explain please?
Cheers
Mark

1. Take top pipe off APC valve (it's mounted to the cobra pipe)
2. Stick a 6mm Bolt into the pipe and clamp.
3. Test drive

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What we need are more people who specialise in the impossible

Yes. The non-return valves can stick in the vapour return (EVAP. This means that the turbo control doesn't get the right signals. So the "bolt mod" disconnects the EVAP system.

On the black plastic valve on the top front of the engine by the inlet cobra pipe - the one with three black plastic pipes coming from it. Pull off the top pipe of the three. Then stick a bolt into the pipe and leave the outlet from the valve free to air.

Job done.

On later cars from around 2005 or so, Saab did this themselves, so the pipework was probably not really needed in the first place....

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Everything will be OK in the end. If it's not OK, it's not the end...

Now that I didn't know.

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What we need are more people who specialise in the impossible

Can someone please post a picture of the evap valve, might try this tomorrow to see if it cures my running issues

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2004 2.3 9-5 HOT
1999 Honda CBR1100 XX Blackbird

The APC valve is the black one nearest the camera.




The EVAP valve that sticks is further along the line. But once the pipe is disconnected and blocked, it doesn't matter whether the valve works or not!!

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Everything will be OK in the end. If it's not OK, it's not the end...

Just for info, on my 2007 model the pipe is just connected around the back of the cobra pipe. But the whole leg of the EVAP is removed, instead of blocking it.

Here's a crummy picture of mine.

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Everything will be OK in the end. If it's not OK, it's not the end...

The pipe that's removed in later cars is highlighted in red. The two tees are removed too.

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Everything will be OK in the end. If it's not OK, it's not the end...

Cool. Thanks for the info!

So which bit do you leave to atmosphere?

If I split the pipe on the throttle body side of the valve coming from the inlet pipe and plug that gap, that's the test?

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2004 2.3 9-5 HOT
1999 Honda CBR1100 XX Blackbird

I also had to put a bolt in the pipe on the backside of the throttle body to prevent CELs

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http://www.topcashback.co.uk/ref/rincey
'55 9-5 aero silver
Theres nowt better than a pie sandwich

I posted this cos the boost was only reaching high yellow on the gauge and the felt like it had flat spots (sometimes) in the mid range. Did the bolt mod yesterday and have an instant improvement (especially torque) and now boosting into the low red. Cool.
Thanks all!

The big problem with this setup is the check valves. This bolt mod is to stop boost pressure getting to the APC valve from the throttle body. Blocking the top hose stops this but still bleeds boost pressure from the throttlebody into the turbo inlet via the hose connected to the cobra pipe.

Best option, as SGould says is to completely remove the pipe from the T on the evap system, by the purge valve, and use silicone hose to connect the cobra directly to the APC. This will free up a (hopefully) good check valve to replace the one between the throttlebody and evap valve making everything good with the world again.

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It takes 2 to make an argument. And I think both you buggers are wrong....

I had hoped this would cure my high yellow boost level but unfortunatly it did not.... Now where to look next?

Thanks Pug.
My car is a 2000 Aero. Is this extra mod OK for the earlier cars? If so I will deffo try it.

It's only possible on the early cars!! . On later cars, Saab had already removed it themselves...

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Everything will be OK in the end. If it's not OK, it's not the end...

D'oh!
So, I need to connect a hose from the cobra to the APC valve port that's now open to air, to replace the hose with check valve that's currently fitted?

You need to find out if the check valve has failed first. If it has this will fix it. If it hasn't there's likely another issue with the car.

To do this pull the hose going into the back of the throttle body and the hose going onto the evap valve off and try blowing into it from the throttle body side. You shouldn't be able to as the check valve should close. Also try sucking on it (gently) and you should be able to. If the check valve is faulty it will need replacing otherwise there will still be running issues, bolt mod or not.

There would be no harm in performing this mod anyway. Let's be honest, there's a reason Saab did it eventually.

To do a permanent mod try make sense of this.....
Have a look at SGoulds pictures. You can see the pipe going straight from the cobra to the apc.
As far as the rest of the hose goes, follow the hose from the EVAP valve, slightly below and rearwards of the MAF, to the inner wing. Here you can see the tee. The hose that runs forward from here is the one that goes to the cobra. This can be removed albeit with a bit of effort. You can then either replace the tee with an elbow or block this off.
If the check valve has failed but the forward facing one is good, grab a load of silicone hose and get merry with it. Pull the check valve from the forward facing hoses and connect the EVAP valve to the throttle body with the check valve inline using silicone pipe.

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It takes 2 to make an argument. And I think both you buggers are wrong....

Thanks Pug.
A little project for the weekend I think...

Have a look here:- http://www.saabcentral.com/forums/showt ... p?t=203271

I would just replace the valve if faulty.

Don't know if these would work:- http://www.ebay.co.uk/itm/Diesel-Non-Re ... 3f1bdf887d

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2000 9-3 2.3 viggen convertible.
NoobTune Stage 3, with Wossners.
http://miikka.org/saabcode/