Engine symptoms has garage stumped.

**Blagmeister** · 15th July 2009, 19:12

Not long after buying my Vec back in Nov, it developed an intermittent issue. The engine made a "chuffing" sound on gearchange together with a misfire.

On taking the car into the garage [A local Saab Specialists] to undergo a service, they found that my inlet manifold was clogged and the swirl flaps were knackered. My intercooler also had a hold in it. Both these were replaced and for a short while things were much better.

Then I got the same issues back again: chuffing and missing together with a limp mode and an error code which showed a throttle body error. They checked the unit on the bench and it was faulty so a new one was fitted.

Shortly after this I got another error code of P0234 which gave the explanation of "boost pressure control circuit negative deviation". One boost control valve later and I am still gettting this same issue and its driving me nuts.

It seems to only manifest itself when the engine is fully warm, and only on gearchanges at around 2250rpm under gentle-moderate throttle pressure. it sounds like a solenoid or something like it not operating smoothly which would explain the chuffing sound but I am only going on gut feeling.

The garage are suggesting that it could be the turbo which would mean big bucks and frankly I am loathe to spend any more dosh until it can be proven exactly what the problem is. They are a bit stumped and can only suggest now looking at the turbo as the root cause.

Anyone had anything similar, or is there any techies out there who might have an idea of what could be causing this?

I really would appreciate some help 'cos I am at the stage of wanting to go outside and set fire to the chuffing thing!

Phil

**GazVXLINE170** · 15th July 2009, 19:18

I had the manifold and intercooler changed too and it cured my issues, but have they changed the EGR Valve?

Does it also suffer extreme loss of power under 2,000rpm? If so it is most likely the EGR - really common.

Gazza4

**Blagmeister** · 15th July 2009, 20:25

Hi Gazza

They have checked the EGR and its fine. I cleaned it pretty much as soon as I got the car and it was fine then too. They have bench tested it and it all seems to be in order so I am really at a loss as to what to do next.

So far its cost me well over £1k to have all the repairs done and I am still no further down the road.

I'm ready to torch the ********

**Blagmeister** · 16th July 2009, 18:34

Anyone else have any ideas as to what I should try next?

**GazVXLINE170** · 16th July 2009, 18:58

Turbo?

Pretty much at a loss now m8.

Gazza4

**plasma** · 16th July 2009, 19:13

check the vaccum line to the boost valve?

**Blagmeister** · 18th July 2009, 09:41

thanks for the suggestion fellas. the more i think about it the more i think its the turbo. possibly vanes sticking or the wastegate not working properly causing the overboost. if i hoof it then it doesnt do it, but if i pull away gently i get the symptoms like it is not enough pressure to ppen the wastegate fully. or am i way off beam?

**walt1wallace** · 18th July 2009, 22:17

hi had the same problems fault code p0234 was present had checked every thing on the car stripped it all down only to find a air leak on the bottom of my intercooler rad fitted a new one now running perfect back to full power and no funny sounds any more..............