"Knock, knock"..."Who's there?"... "Your engine"...

[Rinzleristron]

I drove down to Laaaandon! yesterday, from South Wales. Now you would probably ask "what sort of idiot would neglect to check his oil and water levels before embarking on such a trip?"... well, ladies and gentleman that idiot would be me.

I did the same trip in April and my roadster laughed in face of Friday night rush hour London traffic, all 2hrs of it.

Yesterday however I got across London village in 45 mins, during which, and I thought my mind was playing tricks, I heard a knocking sound from the engine. It took me just over 2hrs on the M4 to home and the same thing... a knocking not a constant but every now and then, as soon as I turned my head and the stereo down to pin point the noise it was gone again. It wasn't until the end of the journey that I realised it only appeared when going around corners, accelerating quickly or breaking heavily. At which point I thought to myself s**t I've got no oil.

I got home immediately removed the oil cap and checked the dipstick. The engine was smoking away nicely and the dipstick was a beautiful shade of oil free!?

So anyone take a shot at telling me:-

A) Is it feasible that the knock was a result of the oil or lack of or could it be an ignition problem?

B) How has my car not suffered a catastrophic failure?

C) I'm using 5w/40 fully synthetic, any suggestions?

D) Why the **** would you drive in London? (Don't feel that this last question is compulsory)

Here's a image of the car in front of 'The Shard'

[frogger]

Nice picture!  Shame about the rest!

Given the oil level, you're initial suspicions seem very likely.
Borrow a trained ear if your still unsure, should be possible to confirm from the sound and nature of the knock.

In terms of why hasn't it completely failed, I guess is just a matter of time, though it is an impressively long journey without complete failure!

[JudoKilli]

Does it sound like what I posted in this thread?

[Rinzleristron]

Does it sound like what I posted in this thread?

Thanks for the link. It was more tappety if that makes sense!? I put 2ltrs of oil in it which took the level to where it should be on the dip stick. I'm sure the capacity is approx 4ltrs, do Im assuming the engine was not dry, took it for a good drive and there is no more noise.

Did you have any other symptoms, like overheating?

[Wabbitkilla]

Engine refill after a drain and filter swap is 3.7 litres.

[mrzwei]

That was without doubt bottom end knock due to oil starvation. Don't go anywhere without checking the oil level for a bit.
Had the same in a company motor, put a couple of litres in and, surprise suprise the knock went away.

The cause of the oil loss is now the worry.