Bought a E32 1991 730i SE for charity roadtrip. Need help!

[AIbUSE]

Hi Guys,

I bought a 1991 730i SE which is to be used to do a 1500 mile roadtrip through Europe to raise money for UNICEF, the children's charity. The car's been SORN for the last 5 years so needs a bit of work.

I've given it a full service, oil, filters, plugs, etc. but it seems to rev up and down between 1200-1700 rpm on idle. It's smooth through the complete rev range and drives perfectly. I've taken the idle control valve off and given it a good clean but it hasn't resolved it. Any ideas what else it could be?

Also, there were a lot of airlocks in the rad and I have bled the system out, filled it with water and let the engine run for some time. It didn't seem to overheat when I run it for 30 mins or so. However, I took it for a short drive and the temp needle almost hit red. No obvious leaks, any ideas what it could be?

They all sound like common M30 problems but I'm not too familiar with these at all.

Cheers
Ruhul

[djk]

Pulsing idle could be an air leak - check the intake boot, TB gasket, Inlet manifold gasket, rocker cover gasket etc. Not an M30 expert, but have had the same problem on an e30!

[fingerman]

Hhm, good one but you may bey best asking in the following forums ?

http://www.bmw7resource.co.uk/forum/index.php

http://www.the7seriesregister.co.uk/

Tho a lot of M30 experts on here - good luck

[AIbUSE]

I've checked all the above mentioned. It seems steady on start up but then starts pulsing after a short while of running.

[AIbUSE]

Hhm, good one but you may bey best asking in the following forums ?

http://www.bmw7resource.co.uk/forum/index.php

http://www.the7seriesregister.co.uk/

Tho a lot of M30 experts on here - good luck

Cheers fingerman, found most of the other forums not as useful as the Zone but I'll check them out

[djk]

I've checked all the above mentioned. It seems steady on start up but then starts pulsing after a short while of running.

That's exactly the problem I had, v. annoying in an auto! I think it's showing up once the ecu has switched to a 'normal' idle, after a faster/enriched one at start up. Other things would be to check the operation of the air flow meter, but don't ask me how!

[AIbUSE]

I've checked all the above mentioned. It seems steady on start up but then starts pulsing after a short while of running.

That's exactly the problem I had, v. annoying in an auto! I think it's showing up once the ecu has switched to a 'normal' idle, after a faster/enriched one at start up. Other things would be to check the operation of the air flow meter, but don't ask me how!

lol, I doubt it is the AFM as the car drives perfectly when in gear, no surges or hesitations through the rev range.

Cheers

[djk]

If it's stuck open, wouldn't it only show a problem at idle?

[mr_dink]

Check that the throttle position sensor is giving a closed throttle signal.

The ECU needs this signal or the Idle Control Valve will not be able to do it's job.

Throttle position sensor is item 2 in this pic.

http://www.realoem.com/bmw/showparts.do ... g=13&fg=15

Not sure which pins you should be testing though, or even how many there are on an M30.

Anyone else?

[daimlerman]

Cooling system problem sounds like a blocked radiator,not too suprising given that the poor thing has stood for 5 years.Difficult to clean out as well,all those tiny tubes to get furred up. May be worth trying a kettle de-scaler before a new radiator?