Drove fine had a slight turbo squeel but still drove and pulled fine and did not use oil, I broke down and after investigation it would only start with oil cap removed and noticed that alot of pressure in engine and assumed exhaust gases coming back through Engine so checked exhaust and no gases were coming out so I disconnected exhaust from turbo to check if exhaust was blocked but still the same fault so I then bypassed egr valve by blanking on top of manifold and still the same fault so I have now removed turbo and sat it to one side and then started the vehicle and finally we have exhaust gases coming out of engine but now won't start and run which to me it should still start and run even with no turbo attached to the exhaust, I do not wish to get turbo reconditioned even though I no it is on its way out I'm not 100% sure it is causing this fault and hoping that someone has had something similar in past as I've never known a turbo to fail in a way that blocks the turbo and does not let the exhaust gases escape causing them to be blown back into engine and into Engine through valve ports, any help would be much appreciated as I'm running out of ideas but have tried to eliminate everything it could be bit by bit until I find the fault but struggling, thank you

I can't offer you answer on this, but I don't think 'what you think is happening', is actually happening !! Hope that makes sense.

If you block the exhaust normally either the engine will stall (or not start), or things tend to explode due to back pressure, and if you are really lucky sometimes it will stall and explode !

 

 

Hi thank you for the reply but I haven't blocked the exhaust but that is the fault, so I have disconnected bit by bit to try and find the blockage and after removing turbo we have gases escaping now, with turbo attached it just wants to send the exhaust gases thro the egr valve and back into the engine which makes me think there is a fault with the turbo but I've never come across this before.

Stuck turbo gate / gate valve ?

Ok yeah makes sense obviously had under and over boost but never fully stuck but yes I do think I'm on the right track just like to get a second opinion on these things before I go to far and spend too much lol, thank you for your help it's much appreciated.