Porsche Enthusiasts Club Forum

Hi LarJammer, No. I had no boost. From my limited understanding when I connected up the wastegate connection pipe the DME went into safe mode as the cycling valve was continually open or allowing boost too soon. As I tested by clamping the pipe the boost built up and the DME see the cycling valve as closed allowing boost. Other can say I dont know what I'm talking about

So with the WG hose clamped the car should overboost as the ECU cant control it. Since you mentioned your boost gauge doesnt seem to work properly you will need an aftermarket gauge temporarily installed to check the actual boost level under load. this should be done carefully as its easy to wind it up to 1.4bar if you are not paying attention. If you are still not reaching the factory boost level (0.8bar) with the WG hose clamped then more investigation is required (boost leak, faulty turbo, wastegate, ecu etc.) Or just give it to a specialist to sort out...

Today, I replaced the cycling valve with a new Porsche unit. New wastegate hose fitted and test drove. This didn't improve my boost issue. I have investigated further - when the WG hose is removed it'll have boost. Any suggestions what else I should check from these symptom?

considering what you have changed/tested to date and the symptoms described I would assume that the culprit must be the wastegate itself, either stuck open or cracked. I would be getting under the car now to remove the wastegate and see what you have, it won't be easy to remove due to rusted bolts so start by spraying the bolts with something like WD40 or better and let soak for a few days. Keep spraying with fresh WD40 over this time, use a wire brush to get the muck off and let the fresh WD40 soak in further, if these bolts have never been removed before they may prove stubborn and need a more drastic approach, let's hope you don't need that...

Pete

without seeing the car its guess work but you really need to check for boost leaks before buying more parts. and double check all of your plumbing is correct. other possibilities - faulty turbo, wastegate, ecu etc.

I think we can rule out boost leaks due to the car holding boost when the wastegate hose is clamped, the hose itself is new so we must have a problem with the wastegate, it could be simple or terminal in as far as the wastegate itself is concerned...only way to find out now is to remove the wastegate, strip it down and check for cracks or stuck valve...personally I would be taking a close look first round the wastegate to see if you can see any tail tail signs of escaping exhaust gases which may help diagnose the culprit...

Pete

we cant rule anything out yet. it should be overboosting with the wg hose clamped, without any data from the op we dont know if thats the case. a much easier way of testing the wg is to clamp off the hose, take it for a quick blast and feel if the wg exhaust pipe has become hot. if it is, exhaust gas is leaking past the wg. if its still cold the wg is sealed.

Pete, I did notice over time when the hose was clamped it stopped boosting. So, now I've disconnected it from the wg and it boosts. I will have a look at the wg at closer inspection. I know its most properly as old as the car.

If I cant see any major issues externally on the wg I'll get the car to a speicalist to check the boost pressure. I've read trying to remove the wg is a pig of a job. Custom tool mods.