LukeT

2008 series 1 had been gradually losing power over a few weeks. No engine codes at all so was shooting in the dark when it came to diagnosing. Car had extremely rough idle and stalled once 10 seconds after start-up. After replacing (very dirty) air filter and cleaning MAF, found that air intake tube smelled of oil, and there were traces of oil on the old air filter. After this change, car now returns a P0410 (secondary air injection).

Plugs, wires and coils are in good condition, they were replaced circa 5k miles ago, but I have admittedly only visually inspected the plugs and wires.

Loss of power remains but rough idle and stalling are gone. New symptom of awful start-up time - today it took almost 5s before it started, almost thought it was going to flood. She is very slow up the revs and completely cuts out at 6k rpm. The exhaust no longer has that subtle rumble it always did when listening from the back of the car, making me think it was a clogged cat all along. Wanted to verify there's nothing else to do before I go about taking the cat off for inspection.

Loki

iTrader: (1)

Oil in the intake is either overfilled oil or blowby (which is not a great sign). Clean it out and see if it comes back.
​​​​​The symptoms sound like the cat is a possibility, definitely check it out. Bad cats kill engines, and long startup times are not a great indicator. Don't worry about the P0410 for now, it's not what's causing the symptoms.

LukeT

Thanks for this. Will be replacing the cat with a midpipe tomorrow, can worry about the smell later

Would a clogged cat cause the poor start-up times? Or would it be the cat causing the engine to go bad, causing the bad times?

Edit: Found one of the plugs has a hairline crack on housing. Could this be the cause of bad start? As you can tell I'm trying very hard to avoid believing the engine is dead

Loki

iTrader: (1)

You could just get a compression test to see what you're working with. A cat won't usually cause starting problems by itself, that would be more ignition or compression. Do you get a lot of white smoke once it does start after sitting for a while?

LukeT

A test would definitely be in order. A midpipe and new plugs fixed all my aforementioned issues.

I get a little smoke every time, today I got a bit but it stopped before the car warmed up. Only time I get tonnes is after de-flood, as you do I suppose.