2005 Audi 1.8 a4 check engine light on and car now spudders??

No I would not crank the car. If you do not have oil pressure reading then it can cause catastrophic engine failure if you crank or drive. Have you checked the oil level via the dipstick? and if so what was the level?

compression test
check for internal crack in turbo
replace plugs
check for blown head gasket

My 2005 A4 3.0 convertible audi is not a diesel, but I had a similar experience with a low oil signal going on and after checking the oil, which was sufficient, and replacing the dipstick, the light did not come back on until a subsequent trip. The light usualIy went on when I was close to the needing an oil change. I've had the car, a used one, for about two years, and the oil light minimum signal started behaving like yours early. About a week ago the oil pressure warning light came on. I don't know if there's a relationship, but if there is be careful. Audis of our vintage have a problem with sludge build up that damages the oil pump, which is a costly item. If you drive the car with low oil pressure you may seriously/fatally damage the car. I don't know if the sludge, if that's what you have, can be cleaned out, but I'd do it if it can be. My mechanic advised me to trade the car to a dealer rather than fix it. Hope you have better luck!

good chance with that problem you were close most likely a misfire will cause that. it would be either your spark plugs or coil pack. also make sure your vacuum lines are good and air filter is good. also bad gas can cause that problem. the worst outcome would be your throttle body going out on you.

The mechanic should check on the gears form N, R, P, 1st gear, second, third gear of the transmission . you also have to check the oil seals of the gears of the transmission.Don't forget to check also the shift level and the shift fork of the transmission.check the said gears ,the shift fork ,the shift level and the oil seals if they are worn out or destroyed you should replace them.Most of the time if the engine spudders when changing in gears it means that there is a problem in the oil seals of the transmission gears . Don't forget to check also the transmission bearing to be sure. Because it is spuddering .

You have a turbo hose or vacuum hose leak, you need to trace that down..Any intake leaks will cause the traction/check engine lights to light up.

I hope that you had the proper weight oil installed, at your oil change. If your oil is up to the proper level, and it's rattling ,this is VERY bad. White smoke usually means steam in the exhaust, and that means a blown head gasket. Check your coolant level. I wouldn't drive it anymore......until someone knowledgeable can diagnose it!!!!!

NEED TO CHECK WITH A SCANNER , THAT WILL PINPOINT THE PROBLEM. AJ

most cars have a self diagnosis proceedure during and just after startup. this is not a fault unless it appears while going round corners or just generally driving around. you have had the sense to check your levels and pressures then i wouldnt worry too much about it unless it stays on or is as i say on while driving.

The car has entered into fail safe mode. It wil not allow the engine to rev high but allows you only to get to a mechanic or to get some oil into the engine. What's the level like? Is there any trace of leakeage?