E30 Zone

hi, i'm new2 this site and the world ot rwd.
jiust bought a 325i sport. its a 90 wit standard running gear, bar lowering springs (h & r).
have a few wee problems wit it and could do wit some advice from people in the know. I am a hgv mechanic so petrol engines are a wee mistery to me. when cold the engine runs on tick over ok, but when reved is slow to pick up. then when accelerating, if you go over 4500 rpm when u change gear it starts to chug and splutter momentarily. when warm it is ok unless left ticking over and then it hesitates when u first give it throttle.
have an older 325 but it isn't a sport and the engine seems to have some minor differences. have changed the leads and air filter. also the oil levl light is on. how can i check if its the sensor without buyin one as my spars engine has a different sensor.
lastly i heard synthetic gear oil was what was needed for the diff. a hino lorry uses x75w90 so thats what i used but sometimes the diff doen't bite.. any advice. clutches hard to change? troublesome?
thanks for all your help in advance! =

Well, first things to check are the things that can be solved cheaply.

Check fuel filter has been changed recently. I don't think you can take them apart to see the filter itself. Check that the fuel pump is delivering fluid. (Pull off a fuel line and crank the engine, with a mate holding the fuel line. You first need to depresssurise the system by taking out fuse 11, and starting the engine until it dies) Check that there are no cracked fuel lines, thus letting air into the system. The smell of fuel under the car is enough to point this out.

On the ignition side, check that the coil is delivering nice fat sparks, by taking a plug out, put on a rubber glove and hold it near the block. If the plugs are dirty or eroded, change them. Taking the distributer cap off is a bit of a marathon, but the cap could be tracking under load.

Those are standard car checks. But now you have to check for specific e30 problems. Air leaks from old hoses can give hesitations, as can air leaks around the inlet manifold. Put your ear in the engine and listen for whooshing.

Lastly, you have to check for the electronic bits. The throttle position sensor often gets filled with oil, and need to be cleaned out with carb cleaner every 10 years or so. Or it could be the idle control valve, ( doesn't sound like it from your symptoms). If the previous owner has been messing around with the ECU unit, fitting chips etc, he may have inadvertantly shorted something. Again not too likely but possible

The oil light being on could be something as simple as oil on the sender wire. Check it's nice and dry. These engines often leak in that area.

Lastly, use the 'search' facilty on this website, looking for tips on fuel pumps etc.

thanks for that, will have a butchers and let ya know how i get on.

the knock sensor was shot on my saab and that made the engine hesitant... dont know if BMW has one though???

no knock sensors on M20 , good call though M8

intake bellows ok dude? remove the section between TB and AFM and see what the condition is like, often split on the underside and cause same symptoms.

you've covered the basics , I'd suggest changing the blue coolant sender on the 'stat housing too, not mega Ԛ£Ã”šÃ‚£ and causes same gremlins as described.

what has the fuel consumption been like ??

slideways wrote: lastly i heard synthetic gear oil was what was needed for the diff. a hino lorry uses x75w90 so thats what i used but sometimes the diff doen't bite.. any advice. clutches hard to change? troublesome?
thanks for all your help in advance! =

The sport is fitted with an LSD and needs to have LSD only oil, available from the dealers, not sure where else you can get it from though.

engines are different post/pre 88

Simon wrote:

slideways wrote: lastly i heard synthetic gear oil was what was needed for the diff. a hino lorry uses x75w90 so thats what i used but sometimes the diff doen't bite.. any advice. clutches hard to change? troublesome?
thanks for all your help in advance! =

The sport is fitted with an LSD and needs to have LSD only oil, available from the dealers, not sure where else you can get it from though.

Only use lsd oil from the dealers as other lsd oils seem a bit didgy and my old sport diff did not like them

fuel consumption...oh my god!
drive a diesel golf also, talkl about ying and yang.
driving the nuts out of it cause i'm still too excited wit her to be sensible. reckon i get about 15 to the gallon!