[saabster]

Hi Guys

I have read the archives, and have come to the conclusion that my wastegate is not opening causing the boost to go way into the red on full throttle and it then cuts out. My first step was to check the actuator rod which moves back and forward quite freely, but the symptoms are still the same. How far should the rod move? and if it moves can it still be a problem with the wastegate. Should I remove the turbo and clean out the wastegate, or is there something that ca be done with it in situ?

 

[zeke]

Check the hose from the BPC solenoid to the wastegate, first. If there's a crack/hole, then there'll be no controlling the wastegate actuator. I've never seen a bad wastegate on a 9000, but I suppose anything is possible I have had BPC's that gave this symptom - they seem to have to two modes of failing: low boost and too much boost. Usually, it's low boost.

 

[ben hall]

The BPC solenoids themselves are prone to failing, and I'm sure someone here will be along at some point and remind us all what the resistance should be across its various pins. However, I have had a failed solenoid which showed the correct resistances!!

The easiest way to test it is to try a known good one. They only take a few seconds to swap (disconnect the 3 hoses, and undo the 2 bolts holding it to the top of the radiator).

However, before doing that it is worth checking all the hoses for leaks, including the 3 hoses to/from the solenoid, and the other smaller diameter hoses that make up the turbo/vaccuum system. The smaller ones in particular are prone to becoming brittle and cracking with age (you don't say what model/age your car is).

cheers,

Ben.

p.s. my solenoid is, I think, playing up at the moment. So, if there's anyone in the Berkshire area with a known good one I could try.......

 

[zeke]

Resistance (~3 ohms) should be checked between the two outside pins and the middle pin (1-2,3-2).

 

[andrew hume]

I am no expert(see my posts!!!) but shouldn't the BCV that you mention fail safe i.e. allowing boost pressure to get to the wastegate? Since the wastegate is the final safety device I would have thought that this would be the failure mode for it.

 

[saabster]

Ok, wastegate actuator rod is moving freely, and I have checked the resistance across the solenoid. I have 4 ohms across 1-2 and 7 ohms across 2-3. I guess this means my solenoid is shot, am I correct?

 

[saabster]

Well I fitted a new (second hand) BPC solenoid today and it has done the job as far as I can tell, as I didnt have long to test it.

It would seem that it doesnt revert to failsafe mode when this fault occurs, you just have to rely on the safety cutout or drive with a very light foot.