Having had my first BMW for 6 days now, i could do with some help from you guys. Apologies if i'm being stupid but.......

I have a 1993 E34 520i. How do I know if this is the SOHC 1990cc engine or the DOHC 24V unit?

What sort of mpg can I expect? First tankful worked out average of 31mpg, but on the second tank (having got stuck in some traffic for 15 mins yesterday) I have already drained just over a quarter of the tank in 90 miles!

The engine seems a bit slow to accelerate until I hit about 3500rpm then it flies! Is this normal? I've checked the plugs and air filter and it all looks okay (car has full dealer service history and has covered about 87000 miles) Only thing that worries me under the bonnet is a slight hissing noise coming from somewhere under the inlet manifold/throttle body at tickover. If you blip the throttle there is a CHA kind of sound and the noise stops for a second and returns as the revs die down again. Is this normal or have I got a  vacumn leak somewhere?

I'm not a bad mechanic, having had older VW's in the past and owning motorcycles I've had to be! But I don't have a workshop manual for this car at the moment and have no idea how to get to the spaghetti of wires and hoses under the manifold!

Many Thanks in advance for any help anyone can give me on these questions

IIRC the Lump changed in 1991.  You will have the DOHC 24V.

Type your Engine number / Veh. number into the database...accessible from this forum.

MPG.  31 is good.  I get 28 on a long steady run (3.5 hours) at 70mph.  I can break the 30mpg if I do the same journey at 65.  Round town and daily I get 22-24mpg.

That his / cha.  Yep, I have had that.  I meddled and messed with all pipes, played with the Air flow flap.  It went away....I don't know if I cured it, or what I touched to cure it, or if it just self-righted!

Paul

Thanks for that Paul. Where do I find the database you mention?

Cheers