orangecurry said:
Shirley the sensible thing to do would have been to replace the O2 sensor, then test drive?
If that's what they did then whoopee.
But I've never heard of injector problems on the 993 before?
(pops off to Rennlist)
Don't call me Shirley.
They did loads of tests first to rule things out (unfortunately for my wallet this was redoing work, but as it turns out necessary, and Precision also didn't charge me for all the hours the spent!)
Here is some of the work they carried out before they tested the injectors... They didn't go straight to the injectors as I'd told them they had just been tested and came back with a clean bill of health.
They knew cylinder one had an issue as the spark was fouled. They carried out a full test plan of the engine fuel and electrical.
They replaced the O2 sensor but it was still failing emissions. They traced all the wiring back to the DME I.E all voltages earths and resistances.
They carried out a hot engine leak down test number 1 cylinder has 10% leakage, the others are all below this reading. They said that was not high but due to the oil contamination they felt there was an internal fault; either valves, piston rings or bore pick up . They were leaning more towards a valve issue but would need to dismantle the engine to be 100% certain.
In addition, they carried out a smoke test to make sure there wasn't have any air leaks.
They did pre and post cat tests to understand the effect of my FabSpeed 200 cell cats... The fabspeed has the O2 sensor on one side, not in the middle which makes it imperfect.
They put video cameras in there to see what was happing (I can't remember exactly where.)
Then as one last check before embarking on a rebuild to fix the oil leak they swapped out the injectors with ones they had in the shop. And emissions when right down to acceptable levels.
So the said I didn't have to do the rebuild unless I wanted to address the oil leak immediately. I think they said it was likely a valve issue. But the car is now fine to drive and passes emission tests.
I'm going to drive it and then get the oil leak fixed in the oil leak fixed next year, spread the costs out a bit.
What gives me comfort is the problem is no longer 'unidentified', I know what the oil leak issue is and I can plan to get it fixed and it's not urgent.