[Mk2] [Turbo] Lambda sensor and Turbo question (not related) with pics

[PlasticMonster]

Lamda Sensor:

My engine is being rebuilt soon, is currently being checked over (stripped down). They have found the lamda sensor was not put on properly when originally installed during the last rebuild by the previous owner (back in December 08). It was put on leaving what looks like a small gap between the gasket.

Pic below:



What effect would this have had on the engine running? Looking for possible reasons for the faliure. (suspected conrods have come loose).

Turbo:

The turbo is a stage 1 Turbo technics CT26.

On top of it is what looks to be some type of feed pipe that has been blanked off.

Pic Below:



Could anyone tell me what this is and why this might have been done?

Additionally should I change this during the rebuild (eg: attach what has been removed) ?

Thanks in advance for your help.

[b4rk3r]

the pipe from the turbo, is the pipe to the actuator i believe.. but if that has always been blanked off then i'd imagine the wastegate would never open, and you'd be hitting fuel cut all the time or running as much boost as the turbo could make. i'm sure somebody will confirm soon.
Conrods coming loose is probably caused by knock/det.

I'll let someone that knows confirm

[PlasticMonster]

Thanks B4rk3r, does anyone know if this is correct?

The car did vent to atmousphere, when I came off the trottle so im assuming that it didnt build up all the pressure?

The lamda helps on the air fuel mixture doesnt it? If this is wrong (the poor seal) could that have caused detonation?

[b4rk3r]

when you get det the standard ecu should go hit fuel cut though


If that pipe was never connected to the actuator then the wastegate wouldn't open... What boost were you running?

[PlasticMonster]

The aftermarket gauge I have stated roughly 0.5 bar first and second gear and 0.7 maybe slightly over in third+

No boost controller ever fitted either EBC or manual as I thought the engine was still new and should be left to settle for a little bit.

I am partially to blame, I had let the oil get low but the engine tuner who is working on it are telling me that what was in it should easily have been enough to prevent a faliure.

[Wingers]

The lambda sensor doesn't have any effect when you're on-boost but should keep the mixture correct when cruising off-boost. A leak like that shouldn't have had any rfeal effect on reliability but might have been costing you fuel consumption.

As for the turbo, which bit are you talking about that's blanked off?
There's a 2-bolt blanking plate in the middle, but also a pipe on the right hand side of the picture.
The pipe on the right is the feed to the wastegate but it sounds like that's been working fine so I'm guessing that you mean the 2-stud blanking plate on the main bearing housing.

That's ok as well. There should be one plate that's blanked off and another connection on the other side that has a feed pipe that runs to the engine block.



I've heard that these engines are very susseptable to running low oil. I think my old engine went the same way as I'm fairly sure that I spun a bearing due to running low oil and not changing it frequently enough.

Wingers