g'day

ive got a largish vacuum leak after the 02 sensor which means my engine will be running lean until it is fixed.

Now i now running lean can burn out valves, so how bad will the leak have to be for that to happen, and what woudl the signs be? Would it running too hot register on the temp gauge?

I've already done 1500k's with it like this and i haven't noticed any change in performance, i just don't want to f**k up my engine

If you don't want to screw up your engine, get it fixed. Running lean will lead to increased combustion chamber temps (which may increase overall engien temps too), pinging and a good chance of blowing head gaskets.

But I don't quite understand what you mean saying there is a leak after the O2 sensor. A leak before the O2 sensor (usually happens where the extractors/exhaust manifold meets the head) can often lead tot he engine running rich not lean, but after the O2 there will be no effect.

how will having a vaccum leak make the engine run lean? won't it introduce extra oxygen near the sensor and in turn make it THINK that its running lean, with which the ECU will richen things up giving you a rich result?


Cheers